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Kengo A, Nabeemeeah F, Denti P, Sabet R, Okyere-Manu G, Abraham P, Weisner L, Mosala MH, Tshabalala S, Scholefield J, Resendiz-Galvan JE, Martinson NA, Variava E. Assessing potential drug-drug interactions between clofazimine and other frequently used agents to treat drug-resistant tuberculosis. Antimicrob Agents Chemother 2024; 68:e0158323. [PMID: 38597667 PMCID: PMC11064479 DOI: 10.1128/aac.01583-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 03/07/2024] [Indexed: 04/11/2024] Open
Abstract
Clofazimine is included in drug regimens to treat rifampicin/drug-resistant tuberculosis (DR-TB), but there is little information about its interaction with other drugs in DR-TB regimens. We evaluated the pharmacokinetic interaction between clofazimine and isoniazid, linezolid, levofloxacin, and cycloserine, dosed as terizidone. Newly diagnosed adults with DR-TB at Klerksdorp/Tshepong Hospital, South Africa, were started on the then-standard treatment with clofazimine temporarily excluded for the initial 2 weeks. Pharmacokinetic sampling was done immediately before and 3 weeks after starting clofazimine, and drug concentrations were determined using validated liquid chromatography-tandem mass spectrometry assays. The data were interpreted with population pharmacokinetics in NONMEM v7.5.1 to explore the impact of clofazimine co-administration and other relevant covariates on the pharmacokinetics of isoniazid, linezolid, levofloxacin, and cycloserine. Clofazimine, isoniazid, linezolid, levofloxacin, and cycloserine data were available for 16, 27, 21, 21, and 6 participants, respectively. The median age and weight for the full cohort were 39 years and 52 kg, respectively. Clofazimine exposures were in the expected range, and its addition to the regimen did not significantly affect the pharmacokinetics of the other drugs except levofloxacin, for which it caused a 15% reduction in clearance. A posteriori power size calculations predicted that our sample sizes had 97%, 90%, and 87% power at P < 0.05 to detect a 30% change in clearance of isoniazid, linezolid, and cycloserine, respectively. Although clofazimine increased the area under the curve of levofloxacin by 19%, this is unlikely to be of great clinical significance, and the lack of interaction with other drugs tested is reassuring.
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Affiliation(s)
- Allan Kengo
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Firdaus Nabeemeeah
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Ryan Sabet
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - Gifty Okyere-Manu
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - Pattamukkil Abraham
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - Lubbe Weisner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Modiehi Helen Mosala
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - Sibongile Tshabalala
- Bioengineering and Integrated Genomics Group, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Janine Scholefield
- Bioengineering and Integrated Genomics Group, Council for Scientific and Industrial Research, Pretoria, South Africa
| | | | - Neil A. Martinson
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
- Johns Hopkins University Center for Tuberculosis Research, Division of Infectious Diseases, School of Medicine, Baltimore, Maryland, USA
| | - Ebrahim Variava
- Perinatal HIV Research Unit (PHRU), University of the Witwatersrand, Johannesburg, South Africa
- Department of Internal Medicine, University of the Witwatersrand, Klerksdorp/Tshepong Hospital Complex North-West Province, Klerksdorp-Tshepong, South Africa
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Sanghavi K, Ribbing J, Rogers JA, Ahmed MA, Karlsson MO, Holford N, Chasseloup E, Ahamadi M, Kowalski KG, Cole S, Kerwash E, Wade JR, Liu C, Wang Y, Trame MN, Zhu H, Wilkins JJ. Covariate modeling in pharmacometrics: General points for consideration. CPT Pharmacometrics Syst Pharmacol 2024; 13:710-728. [PMID: 38566433 PMCID: PMC11098153 DOI: 10.1002/psp4.13115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/15/2024] [Accepted: 02/05/2024] [Indexed: 04/04/2024] Open
Abstract
Modeling the relationships between covariates and pharmacometric model parameters is a central feature of pharmacometric analyses. The information obtained from covariate modeling may be used for dose selection, dose individualization, or the planning of clinical studies in different population subgroups. The pharmacometric literature has amassed a diverse, complex, and evolving collection of methodologies and interpretive guidance related to covariate modeling. With the number and complexity of technologies increasing, a need for an overview of the state of the art has emerged. In this article the International Society of Pharmacometrics (ISoP) Standards and Best Practices Committee presents perspectives on best practices for planning, executing, reporting, and interpreting covariate analyses to guide pharmacometrics decision making in academic, industry, and regulatory settings.
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Affiliation(s)
| | | | | | - Mariam A. Ahmed
- Quantitative Clinical Pharmacology, Takeda PharmaceuticalCambridgeMassachusettsUSA
| | | | - Nick Holford
- Department of Pharmacology & Clinical PharmacologyUniversity of AucklandAucklandNew Zealand
| | | | | | | | - Susan Cole
- Medical and Healthcare product Regulatory Agency (MHRA)LondonUK
| | - Essam Kerwash
- Medical and Healthcare product Regulatory Agency (MHRA)LondonUK
| | | | - Chao Liu
- Applied Innovation Quantitative Solutions, BeiGeneWashingtonDCUSA
| | - Yaning Wang
- Createrna Science and TechnologyClarksburgMarylandUSA
| | - Mirjam N. Trame
- Integrated Drug Development Northeast Regional LeadCertaraMassachusettsUSA
| | - Hao Zhu
- Division of Pharmacometrics, Office of Clinical PharmacologyCenter for Drug Evaluation and Research, Food and Drug AdministrationSilver SpringsMarylandUSA
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O'Hanlon CJ, Sumpter A, Anderson BJ, Hannam JA. Time-Varying Clearance in Milrinone Pharmacokinetics from Premature Neonates to Adolescents. Clin Pharmacokinet 2024; 63:695-706. [PMID: 38613610 PMCID: PMC11106138 DOI: 10.1007/s40262-024-01372-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2024] [Indexed: 04/15/2024]
Abstract
BACKGROUND AND OBJECTIVES Milrinone is an inotrope and vasodilator used for prophylaxis or treatment of low cardiac output syndrome after weaning from cardiopulmonary bypass (CPB). It is renally eliminated and has an acceptable therapeutic range of 100-300 μg/L, but weight-based dosing alone is associated with poor target attainment. We aimed to develop a population pharmacokinetic model for milrinone from premature neonates to adolescents, and to evaluate how age, renal function and recovery from CPB may impact dose selection. METHODS Fifty paediatric patients (aged 4 days to 16 years) were studied after undergoing cardiac surgery supported by CPB. Data from 29 premature neonates (23-28 weeks' postmenstrual age) treated for prophylaxis of low systemic blood flow were available for a pooled pharmacokinetic analysis. Population parameters were estimated using non-linear mixed effects modelling (NONMEM 7.5.1). RESULTS There were 369 milrinone measurements available for analysis. A one-compartment model with zero-order input and first-order elimination was used to describe milrinone disposition. Population parameters were clearance 17.8 L/70 kg [95% CI 15.8-19.9] and volume 20.4 L/h/70 kg [95% CI 17.8-22.1]. Covariates included size, postmenstrual age and renal function for clearance, and size and postnatal age for volume. Milrinone clearance is reduced by 39.5% [95% CI 24.0-53.7] immediately after bypass, and recovers to baseline clearance with a half-time of 12.0 h [95% CI 9.7-15.2]. Milrinone volume was 2.07 [95% CI 1.87-2.27] times greater at birth than the population standard and decreased over the first days of life with a half-time of 0.977 days [95% CI 0.833-1.12]. CONCLUSION Milrinone is predominately renally eliminated and so renal function is an important covariate describing variability in clearance. Increasing clearance over time likely reflects increasing cardiac output and renal perfusion due to milrinone and return to baseline following CPB.
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Affiliation(s)
- Conor J O'Hanlon
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Anita Sumpter
- Department of Anaesthesia, Auckland Hospital, Auckland, New Zealand
| | - Brian J Anderson
- Department of Anaesthesia, Auckland Hospital, Auckland, New Zealand
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Jacqueline A Hannam
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand.
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Holford N, O'Hanlon CJ, Allegaert K, Anderson B, Falcão A, Simon N, Lo YL, Thomson AH, Sherwin CM, Jacqz-Aigrain E, Llanos-Paez C, Hennig S, Mockus L, Kirkpatrick C. A physiological approach to renal clearance: From premature neonates to adults. Br J Clin Pharmacol 2023. [PMID: 38031322 DOI: 10.1111/bcp.15978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/13/2023] [Accepted: 11/23/2023] [Indexed: 12/01/2023] Open
Abstract
AIMS We propose using glomerular filtration rate (GFR) as the physiological basis for distinguishing components of renal clearance. METHODS Gentamicin, amikacin and vancomycin are thought to be predominantly excreted by the kidneys. A mixed-effects joint model of the pharmacokinetics of these drugs was developed, with a wide dispersion of weight, age and serum creatinine. A dataset created from 18 sources resulted in 27,338 drug concentrations from 9,901 patients. Body size and composition, maturation and renal function were used to describe differences in drug clearance and volume of distribution. RESULTS This study demonstrates that GFR is a predictor of two distinct components of renal elimination clearance: (1) GFR clearance associated with normal GFR and (2) non-GFR clearance not associated with normal GFR. All three drugs had GFR clearance estimated as a drug-specific percentage of normal GFR (gentamicin 39%, amikacin 90% and vancomycin 57%). The total clearance (sum of GFR and non-GFR clearance), standardized to 70 kg total body mass, 176 cm, male, renal function 1, was 5.58 L/h (95% confidence interval [CI] 5.50-5.69) (gentamicin), 7.77 L/h (95% CI 7.26-8.19) (amikacin) and 4.70 L/h (95% CI 4.61-4.80) (vancomycin). CONCLUSIONS GFR provides a physiological basis for renal drug elimination. It has been used to distinguish two elimination components. This physiological approach has been applied to describe clearance and volume of distribution from premature neonates to elderly adults with a wide dispersion of size, body composition and renal function. Dose individualization has been implemented using target concentration intervention.
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Affiliation(s)
- Nick Holford
- Department of Pharmacology & Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Conor J O'Hanlon
- Department of Pharmacology & Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
- Department of Hospital Pharmacy, Erasmus MC, Rotterdam, The Netherlands
| | - Brian Anderson
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Amilcar Falcão
- Faculty of Pharmacy, Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal
| | - Nicolas Simon
- Aix Marseille Univ, Hop Sainte Marguerite, Service de Pharmacologie clinique, Marseille, France
| | - Yoke-Lin Lo
- Department of Pharmacy Practice, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Alison H Thomson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Catherine M Sherwin
- University of Otago, Dunedin, New Zealand
- University of Utah, Salt Lake City, Utah, USA
- Department of Pediatrics, Wright State University Boonshoft School of Medicine/Dayton Children's Hospital, Dayton, Ohio, USA
| | - Evelyne Jacqz-Aigrain
- Paediatric Pharmacology and Pharmacogenetics, APHP Hôpital Saint-Louis - University Paris Cité, Paris, France
| | | | - Stefanie Hennig
- University of Queensland, Brisbane, Australia
- Certara, Inc., Princeton, New Jersey, USA
| | - Linas Mockus
- Chemical Engineering Department, Purdue University, West Lafayette, Indiana, USA
| | - Carl Kirkpatrick
- Monash Institute of Pharmaceutical Sciences, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Melbourne, Australia
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Kengo A, Nabisere R, Gausi K, Musaazi J, Buzibye A, Omali D, Aarnoutse R, Lamorde M, Dooley KE, Sloan DJ, Denti P, Sekaggya-Wiltshire C. Dolutegravir pharmacokinetics in Ugandan patients with TB and HIV receiving standard- versus high-dose rifampicin. Antimicrob Agents Chemother 2023; 67:e0043023. [PMID: 37850738 PMCID: PMC10648962 DOI: 10.1128/aac.00430-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/13/2023] [Indexed: 10/19/2023] Open
Abstract
Higher rifampicin doses may improve tuberculosis treatment outcomes. This could however exacerbate the existing drug interaction with dolutegravir. Moreover, the metabolism of dolutegravir may also be affected by polymorphism of UGT1A1, a gene that codes for uridine diphosphate glucuronosyltransferase. We used population pharmacokinetic modeling to compare the pharmacokinetics of dolutegravir when coadministered with standard- versus high-dose rifampicin in adults with tuberculosis and HIV, and investigated the effect of genetic polymorphisms. Data from the SAEFRIF trial, where participants were randomized to receive first-line tuberculosis treatment with either standard- 10 mg/kg or high-dose 35 mg/kg rifampicin alongside antiretroviral therapy, were used. The dolutegravir model was developed with 211 plasma concentrations from 44 participants. The median (interquartile range) rifampicin area under the curve (AUC) in the standard- and high-dose arms were 32.3 (28.7-36.7) and 153 (138-175) mg·h/L, respectively. A one-compartment model with first-order elimination and absorption through transit compartments best described dolutegravir pharmacokinetics. For a typical 56 kg participant, we estimated a clearance, absorption rate constant, and volume of distribution of 1.87 L/h, 1.42 h-1, and 12.4 L, respectively. Each 10 mg·h/L increase in the AUC of coadministered rifampicin from 32.3 mg·h/L led to a 2.3 (3.1-1.4) % decrease in dolutegravir bioavailability. Genetic polymorphism of UGT1A1 did not significantly affect dolutegravir pharmacokinetics. Simulations of trough dolutegravir concentrations show that the 50 mg twice-daily regimen attains both the primary and secondary therapeutic targets of 0.064 and 0.3 mg/L, respectively, regardless of the dose of coadministered rifampicin, unlike the once-daily regimen.
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Affiliation(s)
- Allan Kengo
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Ruth Nabisere
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Kamunkhwala Gausi
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Joseph Musaazi
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Allan Buzibye
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Denis Omali
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Rob Aarnoutse
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mohammed Lamorde
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Kelly E. Dooley
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Centre, Nashville, Tennessee, USA
| | - Derek James Sloan
- Division of Infection and Global Health, School of Medicine, University of St. Andrews, St Andrews, United Kingdom
| | - Paolo Denti
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
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Kengo A, Gausi K, Nabisere R, Musaazi J, Buzibye A, Omali D, Aarnoutse R, Lamorde M, Dooley KE, Sloan DJ, Sekaggya-Wiltshire C, Denti P. Unexpectedly low drug exposures among Ugandan patients with TB and HIV receiving high-dose rifampicin. Antimicrob Agents Chemother 2023; 67:e0043123. [PMID: 37850737 PMCID: PMC10649026 DOI: 10.1128/aac.00431-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/13/2023] [Indexed: 10/19/2023] Open
Abstract
We characterized the pharmacokinetics of standard- and high-dose rifampicin in Ugandan adults with tuberculosis and HIV taking dolutegravir- or efavirenz-based antiretroviral therapy. A liver model with saturable hepatic extraction adequately described the data, and the increase in exposure between high and standard doses was 4.7-fold. This was lower than what previous reports of dose-exposure nonlinearity would predict and was ascribed to 38% lower bioavailability of the rifampicin-only top-up formulation compared to the fixed-dose combination.
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Affiliation(s)
- Allan Kengo
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Kamunkhwala Gausi
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Ruth Nabisere
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Joseph Musaazi
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Allan Buzibye
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Denis Omali
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Rob Aarnoutse
- Department of Pharmacy, Radboud university medical center, Nijmegen, the Netherlands
| | - Mohammed Lamorde
- Infectious Disease Institute, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Kelly E. Dooley
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Centre, Nashville, Tennessee, USA
| | - Derek James Sloan
- Division of Infection and Global Health, School of Medicine, University of St. Andrews, Scotland, United Kingdom
| | | | - Paolo Denti
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
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Raina M, Ashraf A, Soundararajan A, Mandal AK, Sethi SK. Pharmacokinetics in Critically Ill Children with Acute Kidney Injury. Paediatr Drugs 2023:10.1007/s40272-023-00572-z. [PMID: 37266815 DOI: 10.1007/s40272-023-00572-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/12/2023] [Indexed: 06/03/2023]
Abstract
Acute kidney injury (AKI) is a commonly encountered comorbidity in critically ill children. The coexistence of AKI disturbs drug pharmacokinetics and pharmacodynamics, leading to clinically significant consequences. This can complicate an already critical clinical scenario by causing potential underdosing or overdosing giving way to possible therapeutic failures and adverse reactions. Current available studies offer little guidance to help maneuver such complex dosing regimens and decision-making in pediatric patients as most of them are done on heterogeneous groups of adult populations. Though there are some studies on drug dosing during continuous renal replacement therapy (CRRT), their utility is in question because of the recent advances in CRRT technology. Our review aims to discuss the principles of pharmacokinetics pertinent for honing the existing practices of drug dosing in critically ill children with AKI, and the various complexities and intricate challenges involved. This in turn will provide a framework to help enable caretakers to tailor dosing regimens in complex clinical setups with further ease and precision.
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Affiliation(s)
| | - Amani Ashraf
- Northeast Ohio Medical University, Rootstown, OH, USA
| | - Anvitha Soundararajan
- Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH, USA
| | | | - Sidharth Kumar Sethi
- Pediatric Nephrology, Kidney Institute, Medanta, The Medicity Hospital, Gurgaon, Haryana, 122001, India.
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Kim EH, Choi BM, Kang P, Lee JH, Kim HS, Jang YE, Ji SH, Noh GJ, Cho JY, Kim JT. Pharmacokinetics of dexmedetomidine in pediatric patients undergoing cardiac surgery with cardiopulmonary bypass. Paediatr Anaesth 2023; 33:303-311. [PMID: 36594749 DOI: 10.1111/pan.14626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND Cardiopulmonary bypass can affect the pharmacokinetics of anesthetic agents. AIMS We aimed to evaluate the pharmacokinetics of dexmedetomidine for infants and small children undergoing cardiac surgery with cardiopulmonary bypass based on population pharmacokinetics. METHODS We enrolled 30 pediatric cardiac surgical patients in this study. After anesthetic induction with atropine (0.02 mg/kg), thiopental sodium (5 mg/kg), and fentanyl (2-3 μg/kg), we administered 1 μg/kg of dexmedetomidine for 10 min, followed by administration of 0.5 μg/kg of dexmedetomidine per hour during surgery. At the initiation of cardiopulmonary bypass, 1 μg/kg of dexmedetomidine was infused over 5 min. Arterial blood was obtained at predefined time points. A pharmacokinetic model was developed using NONMEM. Theory-based allometric scaling with fixed exponents was applied. Weight, age, post-menstrual age, fat-free mass, whether to implement cardiopulmonary bypass and temperature were explored as covariates. RESULTS A total of 376 blood samples were obtained from 29 children (age: 20.3 ± 19.3 months, weight: 9.7 ± 4.1 kg). A two-compartment mammillary model with third compartment associated cardiopulmonary bypass procedure best explained the pharmacokinetics of dexmedetomidine. The pharmacokinetic parameter estimates (95% CI) standardized to a 70-kg person were as follows: V1 (L) = 31.6 (17.9-39.5), V2 (L) = 90.1 (44.0-330), Cl (L/min) = 1.08 (0.70-1.25), Q (L/min) = 2.0 (1.05-3.46). Volume for third compartment associated cardiopulmonary bypass procedure (L) = 39.4 (19.3-50.9). Clearance was not influenced by the presence of cardiopulmonary bypass in this model. CONCLUSION When cardiopulmonary bypass is applied, the plasma concentration of dexmedetomidine decreases due to an increase in the volume of distribution, so a loading dose is required to maintain the previous concentration.
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Affiliation(s)
- Eun-Hee Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Byung-Moon Choi
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, Ulsan College of Medicine, Seoul, Korea
| | - Pyoyoon Kang
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Ji-Hyun Lee
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hee-Soo Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Young-Eun Jang
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sang-Hwan Ji
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Gyu-Jeong Noh
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, Ulsan College of Medicine, Seoul, Korea
| | - Joo-Youn Cho
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine, Seoul, Korea
| | - Jin-Tae Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
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Schiavo A, Maldonado C, Vázquez M, Fagiolino P, Trocóniz IF, Ibarra M. Quantitative systems pharmacology Model to characterize valproic acid-induced hyperammonemia and the effect of L-carnitine supplementation. Eur J Pharm Sci 2023; 183:106399. [PMID: 36740101 DOI: 10.1016/j.ejps.2023.106399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/29/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
Valproic acid (VPA) is a short-chain fatty acid widely prescribed in the treatment of seizure disorders and epilepsy syndromes, although its therapeutic value may be undermined by its toxicity. VPA serious adverse effects are reported to have a significant and dose-dependent incidence, many associated with VPA-induced hyperammonemia. This effect has been linked with reduced levels of carnitine; an endogenous compound involved in fatty acid's mitochondrial β-oxidation by facilitation of its entrance via the carnitine shuttle. High exposure to VPA can lead to carnitine depletion causing a misbalance between the intra-mitochondrial β-oxidation and the microsomal ω-oxidation, a pathway that produces toxic metabolites such as 4-en-VPA which inhibits ammonia elimination. Moreover, a reduction in carnitine levels might be also related to VPA-induced obesity and lipids disorder. In turn, L-carnitine supplementation (CS) has been recommended and empirically used to reduce VPA's hepatotoxicity. The aim of this work was to develop a Quantitative Systems Pharmacology (QSP) model to characterize VPA-induced hyperammonemia and evaluate the benefits of CS in preventing hyperammonemia under both chronic treatment and after VPA overdosing. The QSP model included a VPA population pharmacokinetics model that allowed the prediction of total and unbound concentrations after single and multiple oral doses considering its saturable binding to plasma proteins. Predictions of time courses for 2-en-VPA, 4-en-DPA, VPA-glucuronide, carnitine, ammonia and urea levels, and for the relative change in fatty acids, Acetyl-CoA, and glutamate reflected the VPA induced changes and the efficacy of the treatment with L-carnitine. The QSP model was implemented to give a rational basis for the L-carnitine dose selection to optimize CS depending on VPA dosage regime and to assess the currently recommended L-carnitine rescue therapy after VPA overdosing. Results show that a L-carnitine dose equal to the double of the VPA dose using the same interdose interval would maintain the ammonia levels at baseline. The QSP model may be expanded in the future to describe other adverse events linked to VPA-induced changes in endogenous compounds.
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Affiliation(s)
- Alejandra Schiavo
- Department of Pharmaceutical Sciences, Faculty of Chemistry. Universidad de la República. Montevideo, Uruguay; Graduate Program in Chemistry, Faculty of Chemistry, Universidad de la República. Montevideo, Uruguay
| | - Cecilia Maldonado
- Department of Pharmaceutical Sciences, Faculty of Chemistry. Universidad de la República. Montevideo, Uruguay
| | - Marta Vázquez
- Department of Pharmaceutical Sciences, Faculty of Chemistry. Universidad de la República. Montevideo, Uruguay
| | - Pietro Fagiolino
- Department of Pharmaceutical Sciences, Faculty of Chemistry. Universidad de la República. Montevideo, Uruguay
| | - Iñaki F Trocóniz
- Pharmacometrics and Systems Pharmacology Research Unit, Department of Pharmaceutical Technology and Chemistry, School of Pharmacy and Nutrition, University of Navarra. Pamplona, Spain; IdiSNA; Navarra Institute for Health Research, Pamplona, Spain
| | - Manuel Ibarra
- Department of Pharmaceutical Sciences, Faculty of Chemistry. Universidad de la República. Montevideo, Uruguay.
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Anderson BJ, Cortinez LI. Perioperative Acetaminophen Dosing in Obese Children. CHILDREN 2023; 10:children10040625. [PMID: 37189874 DOI: 10.3390/children10040625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/14/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023]
Abstract
Acetaminophen is a commonly used perioperative analgesic drug in children. The use of a preoperative loading dose achieves a target concentration of 10 mg/L associated with a target analgesic effect that is 2.6 pain units (visual analogue scale 1–10). Postoperative maintenance dosing is used to keep this effect at a steady-state concentration. The loading dose in children is commonly prescribed per kilogram. That dose is consistent with the linear relationship between the volume of distribution and total body weight. Total body weight is made up of both fat and fat-free mass. The fat mass has little influence on the volume of distribution of acetaminophen but fat mass should be considered for maintenance dosing that is determined by clearance. The relationship between the pharmacokinetic parameter, clearance, and size is not linear. A number of size metrics (e.g., fat-free and normal fat mass, ideal body weight and lean body weight) have been proposed to scale clearance and all consequent dosing schedules recognize curvilinear relationships between clearance and size. This relationship can be described using allometric theory. Fat mass also has an indirect influence on clearance that is independent of its effects due to increased body mass. Normal fat mass, used in conjunction with allometry, has proven a useful size metric for acetaminophen; it is calculated using fat-free mass and a fraction (Ffat) of the additional mass contributing to total body weight. However, the Ffat for acetaminophen is large (Ffat = 0.82), pharmacokinetic and pharmacodynamic parameter variability high, and the concentration–response slope gentle at the target concentration. Consequently, total body weight with allometry is acceptable for the calculation of maintenance dose. The dose of acetaminophen is tempered by concerns about adverse effects, notably hepatotoxicity associated with use after 2–3 days at doses greater than 90 mg/kg/day.
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11
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Takahashi S, Tsuji Y, Holford N, Ogami C, Kasai H, Kawasuji H, To H, Yamamoto Y. Population Pharmacokinetic Model for Unbound Concentrations of Daptomycin in Patients with MRSA Including Patients Undergoing Hemodialysis. Eur J Drug Metab Pharmacokinet 2023; 48:201-211. [PMID: 36862367 DOI: 10.1007/s13318-023-00820-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2023] [Indexed: 03/03/2023]
Abstract
BACKGROUND AND OBJECTIVE Unbound daptomycin concentrations are responsible for pharmacologically beneficial and adverse effects, although most previous reports have been limited to the use of total concentrations. We developed a population pharmacokinetic model to predict both total and unbound daptomycin concentrations. METHODS Clinical data were collected from 58 patients with methicillin-resistant Staphylococcus aureus including patients undergoing hemodialysis. A total of 339 serum total and 329 unbound daptomycin concentrations were used for model construction. RESULTS Total and unbound daptomycin concentration was explained by a model that assumed first-order distribution with two compartments, and first-order elimination. Normal fat body mass was identified as covariates. Renal function was incorporated as a linear function of renal clearance and independent non-renal clearance. The unbound fraction was estimated to be 0.066 with a standard albumin of 45 g/L and standard creatinine clearance of 100 mL/min. Simulated unbound daptomycin concentration was compared with minimum inhibitory concentration as a measure of clinical effectiveness and exposure-level-related induction of creatine phosphokinase elevation. The recommended doses were 4 mg/kg for patients with severe renal function [creatinine clearance (CLcr) ≤ 30 mL/min] and 6 mg/kg for patients with mild to moderate renal function (CLcr > 30 and ≤ 60 mL/min). A simulation indicated that dose adjusted by body weight and renal function improved target attainment. CONCLUSIONS This population pharmacokinetics model for unbound daptomycin could help clinicians to select the appropriate dose regimen for patients undergoing daptomycin treatment and reduce associated adverse effects.
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Affiliation(s)
- Saki Takahashi
- Department of Medical Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Yasuhiro Tsuji
- Laboratory of Clinical Pharmacometrics, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba, 274-8555, Japan.
| | - Nick Holford
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Chika Ogami
- Department of Medical Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Hidefumi Kasai
- Department of Clinical Pharmacokinetics and Pharmacodynamics, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hitoshi Kawasuji
- Department of Clinical Infectious Diseases, Toyama University Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Hideto To
- Department of Medical Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Yoshihiro Yamamoto
- Department of Clinical Infectious Diseases, Toyama University Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama, 930-0194, Japan
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12
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O'Hanlon CJ, Holford N, Sumpter A, Al‐Sallami HS. Consistent methods for fat-free mass, creatinine clearance, and glomerular filtration rate to describe renal function from neonates to adults. CPT Pharmacometrics Syst Pharmacol 2023; 12:401-412. [PMID: 36691877 PMCID: PMC10014044 DOI: 10.1002/psp4.12924] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/25/2023] Open
Abstract
Quantifying the effect of kidney disease on glomerular filtration rate (GFR) is important when describing variability in the clearance of drugs eliminated by the kidney. We aimed to develop a continuous model for renal function (RF) from prematurity to adulthood based on consistent models for fat-free mass (FFM), creatinine production rate (CPR), and GFR. A model for fractional FFM in premature neonates to adults was developed using pooled data from 4462 subjects and 2847 FFM observations. It was found that girls have an FFM higher than that predicted from adult women based on height, total body mass, and sex, and boys have an FFM lower than adult men until around the onset of puberty, when it approaches adult male values. Data from 108 subjects with measurements of serum creatinine (Scr) and GFR were used to construct a model for CPR. Creatinine clearance was predicted using a model for CPR (based on FFM, postmenstrual age, and sex) and Scr that avoids discontinuous predictions between neonates, children, and adults. Individual CPR may then be used with individual Scr to predict the estimated GFR (eGFR; eGFR = CPR/Scr). A previously published model for human GFR based on 1153 GFR observations in 923 subjects without known kidney disease was updated using the model for fractional FFM to predict individual size and age-consistent values for the expected normal GFR (nGFR). Individual renal function was then calculated using RF = eGFR/nGFR.
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Affiliation(s)
- Conor J. O'Hanlon
- Department of Pharmacology & Clinical PharmacologyUniversity of AucklandAucklandNew Zealand
| | - Nick Holford
- Department of Pharmacology & Clinical PharmacologyUniversity of AucklandAucklandNew Zealand
| | - Anita Sumpter
- Department of AnesthesiaAuckland HospitalAucklandNew Zealand
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13
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Morse JD, Cortinez LI, Anderson BJ. Considerations for Intravenous Anesthesia Dose in Obese Children: Understanding PKPD. J Clin Med 2023; 12:jcm12041642. [PMID: 36836174 PMCID: PMC9960599 DOI: 10.3390/jcm12041642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/09/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
The intravenous induction or loading dose in children is commonly prescribed per kilogram. That dose recognizes the linear relationship between volume of distribution and total body weight. Total body weight comprises both fat and fat-free mass. Fat mass influences the volume of distribution and the use of total body weight fails to recognize the impact of fat mass on pharmacokinetics in children. Size metrics alternative to total body mass (e.g., fat-free and normal fat mass, ideal body weight and lean body weight) have been proposed to scale pharmacokinetic parameters (clearance, volume of distribution) for size. Clearance is the key parameter used to calculate infusion rates or maintenance dosing at steady state. Dosing schedules recognize the curvilinear relationship, described using allometric theory, between clearance and size. Fat mass also has an indirect influence on clearance through both metabolic and renal function that is independent of its effects due to increased body mass. Fat-free mass, lean body mass and ideal body mass are not drug specific and fail to recognize the variable impact of fat mass contributing to body composition in children, both lean and obese. Normal fat mass, used in conjunction with allometry, may prove a useful size metric but computation by clinicians for the individual child is not facile. Dosing is further complicated by the need for multicompartment models to describe intravenous drug pharmacokinetics and the concentration effect relationship, both beneficial and adverse, is often poorly understood. Obesity is also associated with other morbidity that may also influence pharmacokinetics. Dose is best determined using pharmacokinetic-pharmacodynamic (PKPD) models that account for these varied factors. These models, along with covariates (age, weight, body composition), can be incorporated into programmable target-controlled infusion pumps. The use of target-controlled infusion pumps, assuming practitioners have a sound understanding of the PKPD within programs, provide the best available guide to intravenous dose in obese children.
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Affiliation(s)
- James Denzil Morse
- Department of Anaesthesiology, University of Auckland, Park Road, Auckland 1023, New Zealand
| | - Luis Ignacio Cortinez
- División Anestesiología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Brian Joseph Anderson
- Department of Anaesthesiology, University of Auckland, Park Road, Auckland 1023, New Zealand
- Department of Anaesthesia, Auckland Children’s Hospital, Park Road, Private Bag 92024, Auckland 1023, New Zealand
- Correspondence: ; Tel.:+64-9-3074903; Fax: +64-9-3078986
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Population pharmacokinetics and pharmacodynamics of cefazolin using total and unbound serum concentrations in patients with high body weight. Int J Antimicrob Agents 2023; 61:106751. [PMID: 36758780 DOI: 10.1016/j.ijantimicag.2023.106751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 01/04/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023]
Abstract
The objective of this study was to evaluate the steady state pharmacokinetics and pharmacodynamics of cefazolin in patients with a high body weight. Cefazolin was administered by 0.5-h infusions to 11 patients with total body weight (TBW) ≥120 kg receiving 3 g q8h, and 12 patients with TBW <120 kg receiving 2 g q8h. Total and unbound serum concentration-time data obtained from serial blood samples were analysed simultaneously by population pharmacokinetic modelling using NONMEM. Probability of target attainment (PTA) was calculated for various dosing regimens through Monte Carlo simulations based on the cumulative percentage of the dosing interval that the unbound concentration exceeds the minimum inhibitory concentration (MIC) value for the pathogen at steady state (fTMIC) ≥40%, ≥60% and 100%. A two-compartment model with non-linear protein binding and allometric scaling of the central volume of distribution using TBW best characterized both total and unbound concentration-time data. Unbound clearance was significantly associated with creatinine clearance, and maximum protein binding constant was significantly associated with serum albumin concentration and body mass index (P <0.05). Based on unbound concentration-time profiles, all simulated regimens achieved PTA >90% at MIC values ≤2 mg/L using fTMIC ≥40%, at MIC values ≤1 mg/L using fTMIC ≥60%, and at MIC values ≤0.5 mg/L using fTMIC of 100%. At fTMIC ≥60%, 0.5-h infusion of cefazolin 1 g q8h achieved PTA <90% at MIC values ≥2 mg/L in patients with TBW≥120 kg; however, prolonged-infusion and higher-dose regimens improved PTA to >90%. Overall, cefazolin pharmacokinetics are altered considerably in obese patients. Higher-dose and/or prolonged-infusion cefazolin regimens should be considered in patients with TBW ≥120 kg, particularly those with less-susceptible Gram-negative infections.
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15
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Derbalah A, Duffull S, Sherwin CM, Job K, Al‐Sallami H. Optimal dosing of enoxaparin in overweight and obese children. Br J Clin Pharmacol 2022; 88:5348-5358. [PMID: 35816401 PMCID: PMC9795990 DOI: 10.1111/bcp.15459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 06/17/2022] [Accepted: 07/01/2022] [Indexed: 12/30/2022] Open
Abstract
AIM Current enoxaparin dosing guidelines in children are based on total body weight. This is potentially inappropriate in obese children as it may overestimate the drug clearance. Current evidence suggests that obese children may require lower initial doses of enoxaparin, therefore the aim of this work was to characterise the pharmacokinetics of enoxaparin in obese children and to propose a more appropriate dosing regimen. METHODS Data from 196 unique encounters of 160 children who received enoxaparin treatment doses were analysed. Enoxaparin concentration was quantified using the chromogenic anti factor Xa (anti-Xa) assay. Patients provided a total of 552 anti-Xa samples. Existing published pharmacokinetic (PK) models were fitted and evaluated against our dataset using prediction-corrected visual predictive check plots (pcVPCs). A PK model was fitted using a nonlinear mixed-effects modelling approach. The fitted model was used to evaluate the current standard dosing and identify an optimal dosing regimen for obese children. RESULTS Published models of enoxaparin pharmacokinetics in children did not capture the pharmacokinetics of enoxaparin in obese children as shown by pcVPCs. A one-compartment model with linear elimination best described the pharmacokinetics of enoxaparin. Allometrically scaled fat-free mass with an estimated exponent of 0.712 (CI 0.66-0.76) was the most influential covariate on clearance while linear fat-free mass was selected as the covariate on volume. Simulations from the model showed that fat-free mass-based dosing could achieve the target anti-Xa activity at steady state in 77.5% and 78.2% of obese and normal-weight children, respectively, compared to 65.2% and 75.5% for standard total body weight-based dosing. CONCLUSIONS A population PK model that describes the time course of anti-Xa activity of enoxaparin was developed in a paediatric population. Based on this model, a unified dosing regimen was proposed that will potentially improve the success rate of target attainment in overweight/obese patients without the need for patient body size categorisation. Therefore, prospective validation of the proposed approach is warranted.
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Affiliation(s)
| | | | - Catherine M. Sherwin
- Department of PediatricsWright State University Boonshoft School of Medicine/Dayton Children's Hospital. DaytonOHUSA
| | - Kathleen Job
- School of MedicineUniversity of UtahSalt Lake CityUTUSA
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16
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Gausi K, Chirehwa M, Ignatius EH, Court R, Sun X, Moran L, Hafner R, Wiesner L, Rosenkranz SL, de Jager V, de Vries N, Harding J, Gumbo T, Swindells S, Diacon A, Dooley KE, McIlleron H, Denti P. Pharmacokinetics of standard versus high-dose isoniazid for treatment of multidrug-resistant tuberculosis. J Antimicrob Chemother 2022; 77:2489-2499. [PMID: 35678468 PMCID: PMC10146925 DOI: 10.1093/jac/dkac188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 05/13/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The WHO-endorsed shorter-course regimen for MDR-TB includes high-dose isoniazid. The pharmacokinetics of high-dose isoniazid within MDR-TB regimens has not been well described. OBJECTIVES To characterize isoniazid pharmacokinetics at 5-15 mg/kg as monotherapy or as part of the MDR-TB treatment regimen. METHODS We used non-linear mixed-effects modelling to evaluate the combined data from INHindsight, a 7 day early bactericidal activity study with isoniazid monotherapy, and PODRtb, an observational study of patients on MDR-TB treatment including terizidone, pyrazinamide, moxifloxacin, kanamycin, ethionamide and/or isoniazid. RESULTS A total of 58 and 103 participants from the INHindsight and PODRtb studies, respectively, were included in the analysis. A two-compartment model with hepatic elimination best described the data. N-acetyltransferase 2 (NAT2) genotype caused multi-modal clearance, and saturable first-pass was observed beyond 10 mg/kg dosing. Saturable isoniazid kinetics predicted an increased exposure of approximately 50% beyond linearity at 20 mg/kg dosing. Participants treated with the MDR-TB regimen had a 65.6% lower AUC compared with participants on monotherapy. Ethionamide co-administration was associated with a 29% increase in isoniazid AUC. CONCLUSIONS Markedly lower isoniazid exposures were observed in participants on combination MDR-TB treatment compared with monotherapy. Isoniazid displays saturable kinetics at doses >10 mg/kg. The safety implications of these phenomena remain unclear.
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Affiliation(s)
- Kamunkhwala Gausi
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | - Maxwell Chirehwa
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | | | - Richard Court
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa (CIDRI-Africa), Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Xin Sun
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Laura Moran
- Social & Scientific Systems, a DLH Company, Silver Spring, MD, USA
| | - Richard Hafner
- Division of AIDS, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
| | | | | | | | | | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Susan Swindells
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Kelly E Dooley
- Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Helen McIlleron
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa (CIDRI-Africa), Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Paolo Denti
- Division of Clinical Pharmacology, University of Cape Town, Cape Town, South Africa
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17
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Lawson R, Staatz CE, Fraser CJ, Ramachandran S, Teague L, Mitchell R, O'Brien T, Hennig S. Population pharmacokinetic model for once‐daily intravenous busulfan in pediatric subjects describing
time‐associated
clearance. CPT Pharmacometrics Syst Pharmacol 2022; 11:1002-1017. [PMID: 35611997 PMCID: PMC9381908 DOI: 10.1002/psp4.12809] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 11/25/2022] Open
Abstract
This study aimed to characterize the population pharmacokinetics (PK) of busulfan focusing on how busulfan clearance (CL) changes over time during once‐daily administration and assess different methods for measuring busulfan exposure and the ability to achieve target cumulative exposure under different dosing adjustment scenarios in pediatric stem cell transplantation recipients. Daily serial blood sampling was performed and concentration‐time data were analyzed using a nonlinear mixed‐effects approach. The developed PK model was used to assess achievement of target exposure under six dose‐adjustment scenarios based on simulations performed in RStudio (RxODE package)®. A total of 2491 busulfan plasma concentration–time measurements were collected from 95 patients characterizing 379 dosing days. A two‐compartment model with time‐associated CL best described the data with a typical CL of 14.5 L/h for an adult male with 62 kg normal fat mass (NFM; equivalent to 70 kg total body weight), typical volume of distribution central compartment (V1) of 40.6 L/59 kg NFM (equivalent to 70 kg total body weight), and typical volume of distribution peripheral compartment of 3.57 L/62 kg NFM. Model interindividual variability in CL and V1 was 14.7% and 34.9%, respectively, and interoccasional variability in CL was 6.6%. Patient size described by NFM, a maturation component, and time since start of treatment significantly influenced CL. Simulations demonstrated that using model‐based exposure estimates with each dose, and either a proportional dose‐adjustment calculation or model‐based calculated individual CL estimates to support dose adjustments, increased proportion of subjects attaining cumulative exposure within 5% of target compared with using noncompartmental analysis (100% vs. 0%). A time‐associated reduction in CL during once‐daily busulfan treatment was described.
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Affiliation(s)
- Rachael Lawson
- School of PharmacyUniversity of QueenslandBrisbaneQueenslandAustralia
- Pharmacy DepartmentQueensland Children's HospitalBrisbaneQueenslandAustralia
| | | | - Christopher J. Fraser
- Blood and Marrow Transplant ServiceQueensland Children's HospitalBrisbaneQueenslandAustralia
| | | | - Lochie Teague
- Pediatric Blood and Cancer CentreStarship HospitalAucklandNew Zealand
| | - Richard Mitchell
- Kids Cancer CentreSydney Children's HospitalRandwickNew South WalesAustralia
- School of Women & Children's HealthUniversity of New South WalesSydneyNew South WalesAustralia
| | - Tracey O'Brien
- Kids Cancer CentreSydney Children's HospitalRandwickNew South WalesAustralia
- School of Women & Children's HealthUniversity of New South WalesSydneyNew South WalesAustralia
| | - Stefanie Hennig
- Certara, Inc.PrincetonNew JerseyUSA
- School of Clinical Sciences, Faculty of HealthQueensland University of TechnologyBrisbaneAustralia
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18
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Population Pharmacokinetic Modelling of Intravenous Immunoglobulin Treatment in Patients with Guillain-Barré Syndrome. Clin Pharmacokinet 2022; 61:1285-1296. [PMID: 35781631 PMCID: PMC9439991 DOI: 10.1007/s40262-022-01136-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2022] [Indexed: 11/04/2022]
Abstract
Background and Objective Intravenous immunoglobulin (IVIg) at a standard dosage is the treatment of choice for Guillain–Barré syndrome. The pharmacokinetics, however, is highly variable between patients, and a rapid clearance of IVIg is associated with poor recovery. We aimed to develop a model to predict the pharmacokinetics of a standard 5-day IVIg course (0.4 g/kg/day) in patients with Guillain–Barré syndrome. Methods Non-linear mixed-effects modelling software (NONMEM®) was used to construct a pharmacokinetic model based on a model-building cohort of 177 patients with Guillain–Barré syndrome, with a total of 589 sequential serum samples tested for total immunoglobulin G (IgG) levels, and evaluated on an independent validation cohort that consisted of 177 patients with Guillain–Barré syndrome with 689 sequential serum samples. Results The final two-compartment model accurately described the daily increment in serum IgG levels during a standard IVIg course; the initial rapid fall and then a gradual decline to steady-state levels thereafter. The covariates that increased IgG clearance were a more severe disease (as indicated by the Guillain–Barré syndrome disability score) and concomitant methylprednisolone treatment. When the current dosing regimen was simulated, the percentage of patients who reached a target ∆IgG > 7.3 g/L at 2 weeks decreased from 74% in mildly affected patients to only 33% in the most severely affected and mechanically ventilated patients (Guillain–Barré syndrome disability score of 5). Conclusions This is the first population-pharmacokinetic model for standard IVIg treatment in Guillain–Barré syndrome. The model provides a new tool to predict the pharmacokinetics of alternative regimens of IVIg in Guillain–Barré syndrome to design future trials and personalise treatment. Supplementary Information The online version contains supplementary material available at 10.1007/s40262-022-01136-z.
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19
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Barraclough KA, Metz D, Staatz CE, Gorham G, Carroll R, Majoni SW, Cherian S, Swaminathan R, Holford N. Important lack of difference in tacrolimus and mycophenolic acid pharmacokinetics between Aboriginal and Caucasian kidney transplant recipients. Nephrology (Carlton) 2022; 27:771-779. [PMID: 35727904 DOI: 10.1111/nep.14080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/01/2022] [Accepted: 06/15/2022] [Indexed: 11/26/2022]
Abstract
AIM To examine whether differences in tacrolimus and mycophenolic acid (MPA) pharmacokinetics contribute to the poorer kidney transplant outcomes experienced by Aboriginal Australians. METHODS Concentration-time profiles for tacrolimus and MPA were prospectively collected from 43 kidney transplant recipients: 27 Aboriginal and 16 Caucasian. Apparent clearance (CL/F) and distribution volume (V/F) for each individual were derived from concentration-time profiles combined with population pharmacokinetic priors, with subsequent assessment for between-group difference in pharmacokinetics. In addition, population pharmacokinetic models were developed using the prospective dataset supplemented by previously developed structural models for tacrolimus and MPA. The change in NONMEM objective function was used to assess improvement in goodness of model fit. RESULTS No differences were found between Aboriginal and Caucasian groups or empirical Bayes estimates, for CL/F or V/F of MPA or tacrolimus. However, a higher prevalence of CYP3A5 expressers (26% compared with 0%) and wider between-subject variability in tacrolimus CL/F (SD = 5.00 compared with 3.25 L/h/70 kg) were observed in the Aboriginal group, though these differences failed to reach statistical significance (p = .07 and p = .08). CONCLUSION There were no differences in typical tacrolimus or MPA pharmacokinetics between Aboriginal and Caucasian kidney transplant recipients. This means that Bayesian dosing tools developed to optimise tacrolimus and MPA dosing in Caucasian recipients may be applied to Aboriginal recipients. In turn, this may improve drug exposure and thereby transplant outcomes in this group. Aboriginal recipients appeared to have greater between-subject variability in tacrolimus CL/F and a higher prevalence of CYP3A5 expressers, attributes that have been linked with inferior outcomes.
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Affiliation(s)
- Katherine A Barraclough
- Department of Nephrology, Royal Melbourne Hospital, Melbourne, Victoria, Australia.,School of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - David Metz
- Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.,Department of Nephrology, Royal Children's Hospital, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Christine E Staatz
- School of Pharmacy, University of Queensland, Brisbane, Queensland, Australia
| | - Gillian Gorham
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Robert Carroll
- Department of Nephrology, Central Northern Adelaide Renal Transplantation Services, Adelaide, South Australia, Australia.,Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sandawana William Majoni
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia.,Department of Nephrology, Northern Territory Renal Services, Darwin, Northern Territory, Australia.,School of Medicine, Flinders University Northern Territory Medical Program, Darwin, Northern Territory, Australia
| | - Sajiv Cherian
- Renal Services, Alice Springs Hospital, Alice Springs, Northern Territory, Australia
| | | | - Nick Holford
- Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
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20
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Du X, Huang C, Xue L, Jiao Z, Zhu M, Li J, Lu J, Xiao P, Zhou X, Mao C, Zhu Z, Dong J, Liu X, Chen Z, Zhang S, Ding Y, Hu S, Miao L. The Correlation Between Busulfan Exposure and Clinical Outcomes in Chinese Pediatric Patients: A Population Pharmacokinetic Study. Front Pharmacol 2022; 13:905879. [PMID: 35784763 PMCID: PMC9243314 DOI: 10.3389/fphar.2022.905879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/31/2022] [Indexed: 11/21/2022] Open
Abstract
Aims: The aims of the study were to 1) establish a population pharmacokinetic (Pop-PK) model for busulfan in Chinese pediatric patients undergoing hematopoietic stem cell transplantation (HSCT) and then estimate busulfan exposure and 2) explore the association between busulfan exposure and clinical outcomes. Methods: A total of 128 patients with 467 busulfan concentrations were obtained for Pop-PK modeling using nonlinear mixed effect model (NONMEM) software. Sixty-three patients who received the 16-dose busulfan conditioning regimen were enrolled to explore the correlations between clinical outcomes and the busulfan area under the concentration–time curve (AUC) using the Cox proportional hazards regression model, Kaplan–Meier method and logistic regression. Results: The typical values for clearance (CL) and distribution volume (V) of busulfan were 7.71 L h−1 and 42.4 L, respectively. The allometric normal fat mass (NFM) and maturation function (Fmat) can be used to describe the variability in CL, and the fat-free mass (FFM) can be used to describe the variability in V. Patients with AUCs of 950–1,600 µM × min had 83.7% (95% CI: 73.3–95.5) event-free survival (EFS) compared with 55.0% (95% CI: 37.0–81.8) for patients with low or high exposure (p = 0.024). The logistic regression analysis results showed no association between transplant-related toxicities and the busulfan AUC (p > 0.05). Conclusions: The variability in busulfan CL was related to the NFM and Fmat, while busulfan V was related to the FFM. Preliminary analysis results suggested that a busulfan AUC of 950–1,600 µM × min was associated with better EFS in children receiving the 16-dose busulfan regimen.
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Affiliation(s)
- Xiaohuan Du
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
- Department of Pharmacy, The Children’s Hospital of Soochow University, Suzhou, China
| | - Chenrong Huang
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute for Interdisciplinary Drug Research and Translational Sciences, College of Pharmaceutical Science, Soochow University, Suzhou, China
| | - Ling Xue
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
- Department of Pharmacology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Zheng Jiao
- Department of Pharmacy, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Min Zhu
- Department of Pharmacy, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Li
- Department of Hematology and Oncology, The Children’s Hospital of Soochow University, Suzhou, China
| | - Jun Lu
- Department of Hematology and Oncology, The Children’s Hospital of Soochow University, Suzhou, China
| | - Peifang Xiao
- Department of Hematology and Oncology, The Children’s Hospital of Soochow University, Suzhou, China
| | - Xuemei Zhou
- Department of Hematology and Oncology, The Children’s Hospital of Soochow University, Suzhou, China
| | - Chenmei Mao
- Department of Pharmacy, The Children’s Hospital of Soochow University, Suzhou, China
| | - Zengyan Zhu
- Department of Pharmacy, The Children’s Hospital of Soochow University, Suzhou, China
| | - Ji Dong
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiaoxue Liu
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhiyao Chen
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Shichao Zhang
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yiduo Ding
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Shaoyan Hu
- Department of Hematology and Oncology, The Children’s Hospital of Soochow University, Suzhou, China
- *Correspondence: Liyan Miao, ; Shaoyan Hu,
| | - Liyan Miao
- Department of Pharmacy, The First Affiliated Hospital of Soochow University, Suzhou, China
- Institute for Interdisciplinary Drug Research and Translational Sciences, College of Pharmaceutical Science, Soochow University, Suzhou, China
- National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Liyan Miao, ; Shaoyan Hu,
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21
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Cheng V, Abdul-Aziz MH, Burrows F, Buscher H, Corley A, Diehl A, Levkovich BJ, Pellegrino V, Reynolds C, Rudham S, Wallis SC, Welch SA, Roberts JA, Shekar K, Fraser JF. Population pharmacokinetics of ciprofloxacin in critically ill patients receiving extracorporeal membrane oxygenation (an ASAP ECMO study). Anaesth Crit Care Pain Med 2022; 41:101080. [PMID: 35472580 DOI: 10.1016/j.accpm.2022.101080] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 02/07/2022] [Accepted: 02/07/2022] [Indexed: 11/01/2022]
Abstract
INTRODUCTION This study aimed to describe the pharmacokinetics (PK) of ciprofloxacin in critically ill patients receiving ECMO and recommend a dosing regimen that provides adequate drug exposure. METHODS Serial blood samples were taken from ECMO patients receiving ciprofloxacin. Total ciprofloxacin concentrations were measured by chromatographic assay and analysed using a population PK approach with Pmetrics®. Dosing simulations were performed to ascertain the probability of target attainment (PTA) represented by the area under the curve to minimum inhibitory concentration ratio (AUC0-24/MIC) ≥ 125. RESULTS Eight patients were enrolled, of which three received concurrent continuous venovenous haemodiafiltration (CVVHDF). Ciprofloxacin was best described in a two-compartment model with total body weight and creatinine clearance (CrCL) included as significant predictors of PK. Patients not requiring renal replacement therapy generated a mean clearance of 11.08 L/h while patients receiving CVVHDF had a mean clearance of 1.51 L/h. Central and peripheral volume of distribution was 77.31 L and 90.71 L, respectively. ECMO variables were not found to be significant predictors of ciprofloxacin PK. Dosing simulations reported that a 400 mg 8 -hly regimen achieved > 72% PTA in all simulated patients with CrCL of 30 mL/min, 50 mL/min and 100 mL/min and total body weights of 60 kg and 100 kg at a MIC of 0.5 mg/L. CONCLUSION Our study reports that established dosing recommendations for critically ill patients not on ECMO provides sufficient drug exposure for maximal ciprofloxacin activity for ECMO patients. In line with non-ECMO critically ill adult PK studies, higher doses and therapeutic drug monitoring may be required for critically ill adult patients on ECMO.
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Affiliation(s)
- Vesa Cheng
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia; Adult Intensive Care Services and Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia; Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Mohd H Abdul-Aziz
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Fay Burrows
- Department of Pharmacy, St Vincent's Hospital, Sydney, New South Wales, Australia
| | - Hergen Buscher
- Department of Intensive Care Medicine, St Vincent's Hospital, Sydney, New South Wales, Australia; St Vincent's Centre for Applied Medical Research, University of New South Wales, Sydney, New South Wales, Australia
| | - Amanda Corley
- Adult Intensive Care Services and Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia
| | - Arne Diehl
- Department of Intensive Care and Hyperbaric Medicine, The Alfred Hospital, Melbourne, Victoria, Australia and School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Bianca J Levkovich
- Experiential Development and Graduate Education and Centre for Medicines Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
| | - Vincent Pellegrino
- Department of Intensive Care and Hyperbaric Medicine, The Alfred Hospital, Melbourne, Victoria, Australia and School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Claire Reynolds
- Department of Intensive Care Medicine, St Vincent's Hospital, Sydney, New South Wales, Australia
| | - Sam Rudham
- Department of Intensive Care Medicine, St Vincent's Hospital, Sydney, New South Wales, Australia
| | - Steven C Wallis
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Susan A Welch
- Department of Pharmacy, St Vincent's Hospital, Sydney, New South Wales, Australia
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia; Department of Intensive Care Medicine and Pharmacy, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France.
| | - Kiran Shekar
- Adult Intensive Care Services and Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia; Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia; Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia; Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia
| | - John F Fraser
- Adult Intensive Care Services and Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia; Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia; Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia; Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia
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22
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Morse JD, Cortinez LI, Anderson BJ. Pharmacokinetic Pharmacodynamic Modelling Contributions to Improve Paediatric Anaesthesia Practice. J Clin Med 2022; 11:jcm11113009. [PMID: 35683399 PMCID: PMC9181587 DOI: 10.3390/jcm11113009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 12/10/2022] Open
Abstract
The use of pharmacokinetic-pharmacodynamic models has improved anaesthesia practice in children through a better understanding of dose-concentration-response relationships, developmental pharmacokinetic changes, quantification of drug interactions and insights into how covariates (e.g., age, size, organ dysfunction, pharmacogenomics) impact drug prescription. Simulation using information from these models has enabled the prediction and learning of beneficial and adverse effects and decision-making around clinical scenarios. Covariate information, including the use of allometric size scaling, age and consideration of fat mass, has reduced population parameter variability. The target concentration approach has rationalised dose calculation. Paediatric pharmacokinetic-pharmacodynamic insights have led to better drug delivery systems for total intravenous anaesthesia and an expectation about drug offset when delivery is stopped. Understanding concentration-dependent adverse effects have tempered dose regimens. Quantification of drug interactions has improved the understanding of the effects of drug combinations. Repurposed drugs (e.g., antiviral drugs used for COVID-19) within the community can have important effects on drugs used in paediatric anaesthesia, and the use of simulation educates about these drug vagaries.
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Affiliation(s)
- James D. Morse
- Department of Anaesthesiology, University of Auckland, Park Road, Auckland 1023, New Zealand;
| | - Luis Ignacio Cortinez
- División Anestesiología, Escuela de Medicina, Pontificia Universidad Católica de Chile, San Diego de Chile 8331150, Chile;
| | - Brian J. Anderson
- Department of Anaesthesiology, University of Auckland, Park Road, Auckland 1023, New Zealand;
- Correspondence: ; Tel.: +64-9-3074903; Fax: +64-9-3078986
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23
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Hui KHM, Lui CYG, Wu KLA, Chen J, Cheung YT, Lam TNT. Multi-center prospective population pharmacokinetic study and the performance of web-based individual dose optimization application of intravenous vancomycin for adults in Hong Kong: A study protocol. PLoS One 2022; 17:e0267894. [PMID: 35511796 PMCID: PMC9070875 DOI: 10.1371/journal.pone.0267894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 04/12/2022] [Indexed: 11/18/2022] Open
Abstract
A recent consensus guideline recommends migrating the therapeutic drug monitoring practice for intravenous vancomycin for the treatment of methicillin-resistant Staphylococcus aureus infection from the traditional trough-based approach to the Bayesian approach based on area under curve to improve clinical outcomes. To support the implementation of the new strategy for hospitals under Hospital Authority, Hong Kong, this study is being proposed to (1) estimate and validate a population pharmacokinetic model of intravenous vancomycin for local adults, (2) develop a web-based individual dose optimization application for clinical use, and (3) evaluate the performance of the application by comparing the treatment outcomes and clinical satisfaction against the traditional approach. 300 adult subjects prescribed with intravenous vancomycin and not on renal replacement therapy will be recruited for population pharmacokinetic model development and validation. Sex, age, body weight, serum creatinine level, intravenous vancomycin dosing records, serum vancomycin concentrations etc. will be collected from several electronic health record systems maintained by Hospital Authority. Parameter estimation will be performed using non-linear mixed-effect modeling techniques. The web-based individual dose optimization application is based on a previously reported application and is built using R and the package shiny. Data from another 50 subjects will be collected during the last three months of the study period and treated as informed by the developed application and compared against historical control for clinical outcomes. Since the study will incur extra blood-taking procedures from patients, informed consent is required. Other than that, recruited subjects should receive medical treatments as usual. Identifiable patient data will be available only to site investigators and clinicians in each hospital. The study protocol and informed consent forms have been approved by the Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee (reference number: NTEC-2021-0215) and registered at the Chinese Clinical Trial Registry (registration number: ChiCTR2100048714).
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Affiliation(s)
- Ka Ho Matthew Hui
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Chung Yan Grace Lui
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Ka Lun Alan Wu
- Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong East Cluster, Hospital Authority of Hong Kong, Hong Kong, China
| | - Jason Chen
- Department of Pharmacy, Ruttonjee and Tang Shiu Kin Hospitals, Hong Kong East Cluster, Hospital Authority, Hong Kong, China
| | - Yin Ting Cheung
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- * E-mail: (TNTL); (YTC)
| | - Tai Ning Teddy Lam
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- * E-mail: (TNTL); (YTC)
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24
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Wallenburg E, Ter Heine R, Schouten JA, Raaijmakers J, Ten Oever J, Kolwijck E, Burger DM, Pickkers P, Frenzel T, Brüggemann RJM. An Integral Pharmacokinetic Analysis of Piperacillin and Tazobactam in Plasma and Urine in Critically Ill Patients. Clin Pharmacokinet 2022; 61:907-918. [PMID: 35377133 PMCID: PMC9249689 DOI: 10.1007/s40262-022-01113-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND OBJECTIVES Although dose optimization studies have been performed for piperacillin and tazobactam separately, a combined integral analysis is not yet reported. As piperacillin and tazobactam pharmacokinetics are likely to show correlation, a combined pharmacokinetic model should be preferred to account for this correlation when predicting the exposure. Therefore, the aim of this study was to describe the pharmacokinetics and evaluate different dosing regimens of piperacillin and tazobactam in critically ill patients using an integral population pharmacokinetic model in plasma and urine. METHODS In this observational study, a total of 39 adult intensive care unit patients receiving piperacillin-tazobactam as part of routine clinical care were included. Piperacillin and tazobactam concentrations in plasma and urine were measured and analyzed using non-linear mixed-effects modeling. Monte Carlo simulations were performed to predict the concentrations for different dosing strategies and different categories of renal function. RESULTS A combined two-compartment linear pharmacokinetic model for both piperacillin and tazobactam was developed, with an output compartment for the renally excreted fraction. The addition of 24-h urine creatinine clearance significantly improved the model fit. A dose of 12/1.5 g/24 h as a continuous infusion is sufficient to reach a tazobactam concentration above the target (2.89 mg/L) and a piperacillin concentration above the target of 100% f T>1×MIC (minimum inhibitory concentration [MIC] ≤ 16 mg/L). To reach a target of 100% f T>5×MIC with an MIC of 16 mg/L, piperacillin doses of up to 20 g/24 h are inadequate. Potential toxic piperacillin levels were reached in 19.6% and 47.8% of the population with a dose of 12 g/24 h and 20 g/24 h, respectively. CONCLUSIONS A regular dose of 12/1.5 g/24 h is sufficient in > 90% of the critically ill population to treat infections caused by Escherichia coli and Klebsiella pneumoniae with MICs ≤ 8 mg/L. In case of infections caused by Pseudomonas aeruginosa with an MIC of 16 mg/L, there is a fine line between therapeutic and toxic exposure. Dosing guided by renal function and therapeutic drug monitoring could enhance target attainment in such cases. CLINICALTRIALS GOV IDENTIFIER NCT03738683.
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Affiliation(s)
- Eveline Wallenburg
- Department of Pharmacy, Radboud University Medical Center, Radboud Institute for Health Sciences, 864, Radboudumc, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands.
| | - Rob Ter Heine
- Department of Pharmacy, Radboud University Medical Center, Radboud Institute for Health Sciences, 864, Radboudumc, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Jeroen A Schouten
- Department of Intensive Care, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jelmer Raaijmakers
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jaap Ten Oever
- Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eva Kolwijck
- Department of Medical Microbiology, Jeroen Bosch Ziekenhuis, Den Bosch, The Netherlands
| | - David M Burger
- Department of Pharmacy, Radboud University Medical Center, Radboud Institute for Health Sciences, 864, Radboudumc, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands.,Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Peter Pickkers
- Department of Intensive Care, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tim Frenzel
- Department of Intensive Care, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud University Medical Center, Radboud Institute for Health Sciences, 864, Radboudumc, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands.,Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
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25
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Morse JD, Stanescu I, Atkinson HC, Anderson BJ. Population Pharmacokinetic Modelling of Acetaminophen and Ibuprofen: the Influence of Body Composition, Formulation and Feeding in Healthy Adult Volunteers. Eur J Drug Metab Pharmacokinet 2022; 47:497-507. [PMID: 35366213 PMCID: PMC9232434 DOI: 10.1007/s13318-022-00766-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND OBJECTIVE Combined acetaminophen and ibuprofen are common antipyretic and analgesic drugs. Formulation and feeding affect drug absorption. Drug clearance has a nonlinear relationship with total body weight. The covariate effect of fat mass on acetaminophen and ibuprofen pharmacokinetics remains unexplored. This study sought to quantify acetaminophen and ibuprofen pharmacokinetics with intravenous, tablet, sachet and oral suspension formulations in fed and fasted states. METHODS Pooled time-concentration data for acetaminophen and ibuprofen were available from fasting and fed healthy adults. Data from intravenous, tablet, sachet and suspension formulations were analysed using nonlinear mixed-effects models. Body composition was considered as a covariate on clearances and volumes of distribution (Vd). Size metrics investigated were total body weight, fat and fat-free mass. Theory-based allometry was used to scale pharmacokinetic parameters to a 70 kg individual. A factor on absorption half-life and lag time quantified delays due to feeding for oral formulations. Pharmacokinetic-pharmacodynamic simulations were used to explore the time courses of pain response for acetaminophen and ibuprofen for each formulation. RESULTS Pooled data included 116 individuals (18-49 years, 49-116 kg) with 6095 acetaminophen and 6046 ibuprofen concentrations available for analysis. A two-compartment pharmacokinetic model with first-order elimination described disposition for both drugs. Normal fat mass was the best covariate to describe acetaminophen clearance (CL), with a factor for fat contribution (FFATCL) of 0.816. Acetaminophen volume of distribution was described using total body weight. Normal fat mass was the best covariate to describe ibuprofen clearance (FFATCL = 0.863) and volume of distribution: (FFATV = 0.718). Clearance and central volume of distribution were 24.0 L/h/70 kg and 43.5 L/h/70 kg for acetaminophen. Ibuprofen clearance and central volume of distribution were 3.79 L/h/70 kg and 10.5 L/h/70 kg. Bioavailability and absorption half-life were 86% and 12 min for acetaminophen and 94% and 27 min for ibuprofen. Absorption lag times were 5.3 min and 6.7 min for acetaminophen and ibuprofen, respectively. Feeding increased both absorption half-life and absorption lag time when compared to the tablet formulation under fasting conditions. Feeding had the most pronounced effect on the lag time associated with tablet formulation for both drugs. Time to a pain score reduction of 2 points (visual analogue score, 0-10) differed by only 5-10 min across all formulations for acetaminophen and ibuprofen. CONCLUSION Fat mass was an important covariate to describe acetaminophen and ibuprofen pharmacokinetics. The absorption half-lives of acetaminophen and ibuprofen were increased in fed states. The delay in absorption, quantified by a lag time, was protracted for both drugs.
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Affiliation(s)
- James D Morse
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Park Road, Auckland, 1023, New Zealand
| | | | | | - Brian J Anderson
- Department of Anaesthesiology, University of Auckland, Park Road, Auckland, 1023, New Zealand. .,Department of Anaesthesia, Auckland Children's Hospital, Park Road, Private Bag 92024, Auckland, New Zealand.
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26
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Model-Informed Precision Dosing of Linezolid in Patients with Drug-Resistant Tuberculosis. Pharmaceutics 2022; 14:pharmaceutics14040753. [PMID: 35456587 PMCID: PMC9032906 DOI: 10.3390/pharmaceutics14040753] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/21/2022] [Accepted: 03/28/2022] [Indexed: 11/23/2022] Open
Abstract
Linezolid is an efficacious medication for the treatment of drug-resistant tuberculosis but has been associated with serious safety issues that can result in treatment interruption. The objectives of this study were thus to build a population pharmacokinetic model and to use the developed model to establish a model-informed precision dosing (MIPD) algorithm enabling safe and efficacious dosing in patients with multidrug- and extensively drug-resistant tuberculosis. Routine hospital therapeutic drug monitoring data, collected from 70 tuberculosis patients receiving linezolid, was used for model development. Efficacy and safety targets for MIPD were the ratio of unbound area under the concentration versus time curve between 0 and 24 h over minimal inhibitory concentration (fAUC0–24h/MIC) above 119 and unbound plasma trough concentration (fCmin) below 1.38 mg/L, respectively. Model building was performed in NONMEM 7.4.3. The final population pharmacokinetic model consisted of a one-compartment model with transit absorption and concentration- and time-dependent auto-inhibition of elimination. A flat dose of 600 mg once daily was appropriate in 67.2% of the simulated patients from an efficacy and safety perspective. Using the here developed MIPD algorithm, the proportion of patients reaching the efficacy and safety target increased to 81.5% and 88.2% using information from two and three pharmacokinetic sampling occasions, respectively. This work proposes an MIPD approach for linezolid and suggests using three sampling occasions to derive an individualized dose that results in adequate efficacy and fewer safety concerns compared to flat dosing.
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27
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Abstract
A clinical review is presented of basic allometric scaling theory and its application to pharmacokinetic models in anesthesia and other fields in the biologic sciences.
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28
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Zinovyev A, Sadovsky M, Calzone L, Fouché A, Groeneveld CS, Chervov A, Barillot E, Gorban AN. Modeling Progression of Single Cell Populations Through the Cell Cycle as a Sequence of Switches. Front Mol Biosci 2022; 8:793912. [PMID: 35178429 PMCID: PMC8846220 DOI: 10.3389/fmolb.2021.793912] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Cell cycle is a biological process underlying the existence and propagation of life in time and space. It has been an object for mathematical modeling for long, with several alternative mechanistic modeling principles suggested, describing in more or less details the known molecular mechanisms. Recently, cell cycle has been investigated at single cell level in snapshots of unsynchronized cell populations, exploiting the new methods for transcriptomic and proteomic molecular profiling. This raises a need for simplified semi-phenomenological cell cycle models, in order to formalize the processes underlying the cell cycle, at a higher abstracted level. Here we suggest a modeling framework, recapitulating the most important properties of the cell cycle as a limit trajectory of a dynamical process characterized by several internal states with switches between them. In the simplest form, this leads to a limit cycle trajectory, composed by linear segments in logarithmic coordinates describing some extensive (depending on system size) cell properties. We prove a theorem connecting the effective embedding dimensionality of the cell cycle trajectory with the number of its linear segments. We also develop a simplified kinetic model with piecewise-constant kinetic rates describing the dynamics of lumps of genes involved in S-phase and G2/M phases. We show how the developed cell cycle models can be applied to analyze the available single cell datasets and simulate certain properties of the observed cell cycle trajectories. Based on our model, we can predict with good accuracy the cell line doubling time from the length of cell cycle trajectory.
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Affiliation(s)
- Andrei Zinovyev
- Institut Curie, PSL Research University, Paris, France
- INSERM, Paris, France
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, Paris, France
- *Correspondence: Andrei Zinovyev,
| | - Michail Sadovsky
- Institute of Computational Modeling (RAS), Krasnoyarsk, Russia
- Laboratory of Medical Cybernetics, V.F.Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
- Federal Research and Clinic Center of FMBA of Russia, Krasnoyarsk, Russia
- Laboratory of Advanced Methods for High-Dimensional Data Analysis, Lobachevsky University, Nizhniy Novgorod, Russia
| | - Laurence Calzone
- Institut Curie, PSL Research University, Paris, France
- INSERM, Paris, France
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, Paris, France
| | - Aziz Fouché
- Institut Curie, PSL Research University, Paris, France
- INSERM, Paris, France
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, Paris, France
| | - Clarice S. Groeneveld
- Cartes d’Identité des Tumeurs (CIT) Program, Ligue Nationale Contre le Cancer, Paris, France
- Oncologie Moleculaire, UMR144, Institut Curie, Paris, France
| | - Alexander Chervov
- Institut Curie, PSL Research University, Paris, France
- INSERM, Paris, France
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, Paris, France
| | - Emmanuel Barillot
- Institut Curie, PSL Research University, Paris, France
- INSERM, Paris, France
- MINES ParisTech, PSL Research University, CBIO-Centre for Computational Biology, Paris, France
| | - Alexander N. Gorban
- Laboratory of Advanced Methods for High-Dimensional Data Analysis, Lobachevsky University, Nizhniy Novgorod, Russia
- Department of Mathematics, University of Leicester, Leicester, United Kingdom
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Optimising the Nadroparin Dose for Thromboprophylaxis During Hemodialysis by Developing a Population Pharmacodynamic Model Using Anti-Xa Levels. Clin Pharmacokinet 2022; 61:1559-1569. [PMID: 36040615 PMCID: PMC9652168 DOI: 10.1007/s40262-022-01162-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2022] [Indexed: 01/31/2023]
Abstract
INTRODUCTION The optimal nadroparin dose in patients undergoing hemodialysis is difficult to determine in clinical practice. Anti-Xa levels ≥ 0.4 IU/mL and < 2.0 IU/mL are suggested to prevent thrombus formation within the extracorporeal circuit whilst minimizing bleeding risk. We aimed to characterize the variability in the association between dose and anti-Xa levels, identify patient and dialysis characteristics that explained this variability, and optimize nadroparin dosing based on the identified characteristics. METHODS Anti-Xa samples were collected in patients who received intravenous nadroparin as thromboprophylaxis during routine dialysis sessions. A population pharmacodynamic model was developed using non-linear mixed-effects modelling. The percentage of patients ≥ 0.4 IU/mL (efficacy) and < 2.0 IU/mL (safety) was simulated for different doses, patient and dialysis characteristics. RESULTS Patients (n = 137) were predominantly receiving standard hemodialysis (84.7% vs. hemodiafiltration 15.3%) and had a mean bodyweight of 76.3 kg (± 16.9). Lean body mass (LBM), mode of dialysis, and dialyzer partially explained between-subject variability in anti-Xa levels. Patients on hemodiafiltration and those receiving hemodialysis with a high LBM (≥ 80 kg) had a low probability (< 29%) of anti-Xa levels ≥ 0.4 IU/mL during the entire dialysis session. All patients, except hemodialysis patients with a low LBM (< 50 kg), had a high probability (> 70%) of peak anti-Xa levels < 2.0 IU/mL. CONCLUSION Mainly patients receiving hemodiafiltration and those receiving hemodialysis with a high LBM can benefit from a higher nadroparin dose than currently used in clinical practice, while having anti-Xa levels < 2.0 IU/mL.
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Caspofungin Population Pharmacokinetic Analysis in Plasma and Peritoneal Fluid in Septic Patients with Intra-Abdominal Infections: A Prospective Cohort Study. Clin Pharmacokinet 2021; 61:673-686. [PMID: 34931282 DOI: 10.1007/s40262-021-01062-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVES The aim of this study was to report the pharmacokinetics (PK) of caspofungin in plasma and peritoneal fluid and to identify optimal dosing strategies in septic patients with intra-abdominal infections. METHODS Eleven patients with secondary peritonitis with septic shock received the standard dosing regimen of caspofungin. Total caspofungin plasma and peritoneal concentrations were subject to a population PK analysis using Pmetrics®. Monte Carlo simulations were performed considering the ratio of 24-h total drug exposure above the minimum inhibitory concentration (AUC24/MIC) in plasma and comparing simulated concentrations versus MIC in peritoneal fluid. RESULTS Fat-free mass (FFM) was retained in the final model of caspofungin, reporting a total clearance (standard deviation) of 0.78 (0.17) L/h and a central volume of distribution of 9.36 (2.61) L. The peritoneal fluid/plasma ratio of caspofungin was 33% on the first day of therapy (AUC24 73.92 (21.93) and 26.03 (9.88) mg*h/L for plasma and peritoneal data, respectively). Dosing simulations supported the use of standard dosing regimens for patients with an FFM < 50 kg for the most susceptible candida species (C. albicans and C. glabrata). For higher FFM, a loading dose of 70 or 100 mg, with a maintenance dose of 70 mg, reached AUC24/MIC ratios for these species. CONCLUSIONS There is moderate penetration of caspofungin into the peritoneal cavity (33%). For empirical treatment, a dose escalation of 100 mg loading dose on the first day is suggested for higher FFM to ensure adequate concentrations into the abdominal cavity for the most susceptible candida species.
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Morse JD, Sundermann M, Hannam JA, Kokki H, Kokki M, Anderson BJ. Population pharmacokinetics of oxycodone: Premature neonates to adults. Paediatr Anaesth 2021; 31:1332-1339. [PMID: 34469607 DOI: 10.1111/pan.14283] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/18/2021] [Accepted: 08/28/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Oxycodone is used in children and adults for the control of acute postoperative pain. Covariate influences such as age, size, and fat mass on oxycodone pharmacokinetic parameters over the human lifespan are poorly quantified. METHODS Pooled oxycodone time-concentration profiles were available from preterm neonates to adults. Data from intravenous, intramuscular, buccal, and epidural formulations were analyzed using nonlinear mixed-effects models. Normal fat mass was used to determine the influence of fat on oxycodone pharmacokinetics. Theory-based allometry was used to scale pharmacokinetic parameters to a 70 kg individual. A maturation function described the increase in clearance in neonates and infants. RESULTS There were 237 subjects (24 weeks postmenstrual age to 75 years; 0.44-110 kg) providing 1317 plasma concentrations. A three-compartment model with first-order elimination best described oxycodone disposition. Population parameter estimates were clearance (CL) 48.6 L.h-1 .70 kg-1 (CV 71%); intercompartmental clearances (Q2) 220 L.h-1 .70 kg-1 (CV 64%); Q3 1.45 L.h-1 .70 kg-1 ; volume of distribution in the central compartment (V1) 98.2 L.70 kg-1 (CV 76%); rapidly equilibrating peripheral compartment (V2) 90.1 L. 70 kg-1 (CV 76%); slow equilibrating peripheral compartment (V3) 28.9 L.70 kg-1 . Total body weight was the best size descriptor for clearances and volumes. Absorption halftimes (TABS ) were: 1.1 minutes for intramuscular, 70 minutes for epidural, 82 minutes for nasogastric, and 159.6 minutes for buccal administration routes. The relative bioavailability after nasogastric administration was 0.673 with a lag time of 8.7 minutes. CONCLUSIONS Clearance matured with age; 8% of the typical adult value at 24 weeks postmenstrual age, 33% in a term neonate and reached 90% of the adult clearance value by the end of the first year of life. Allometric scaling using total body weight was the better size descriptor of oxycodone clearance than fat-free mass.
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Affiliation(s)
- James D Morse
- Department of Pharmacology & Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Milan Sundermann
- Department of Pharmacology & Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Jacqueline A Hannam
- Department of Pharmacology & Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Hannu Kokki
- School of Medicine, University of Eastern Finland, Kuopio, Finland
| | - Merja Kokki
- Department of Anesthesiology and Intensive Care, Kuopio University Hospital, Kuopio, Finland
| | - Brian J Anderson
- Department of Anaesthesiology, Faculty of Medicine and Health Sciences, The University of Auckland, Auckland, New Zealand
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Wallenburg E, Ter Heine R, de Lange DW, van Leeuwen H, Schouten JA, Ten Oever J, Kolwijck E, Burger DM, Pickkers P, Gieling EM, de Maat MM, Frenzel T, Brüggemann RJ. High unbound flucloxacillin fraction in critically ill patients. J Antimicrob Chemother 2021; 76:3220-3228. [PMID: 34463730 PMCID: PMC8598283 DOI: 10.1093/jac/dkab314] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/27/2021] [Indexed: 12/03/2022] Open
Abstract
Objectives To describe the unbound and total flucloxacillin pharmacokinetics in critically ill patients and to define optimal dosing strategies. Patients and methods Observational multicentre study including a total of 33 adult ICU patients receiving flucloxacillin, given as intermittent or continuous infusion. Pharmacokinetic sampling was performed on two occasions on two different days. Total and unbound flucloxacillin concentrations were measured and analysed using non-linear mixed-effects modelling. Serum albumin was added as covariate on the maximum binding capacity and endogenous creatinine clearance (CLCR) as covariate for renal function. Monte Carlo simulations were performed to predict the unbound flucloxacillin concentrations for different dosing strategies and different categories of endogenous CLCR. Results The measured unbound concentrations ranged from 0.2 to 110 mg/L and the observed unbound fraction varied between 7.0% and 71.7%. An integral two-compartmental linear pharmacokinetic model based on total and unbound concentrations was developed. A dose of 12 g/24 h was sufficient for 99.9% of the population to achieve a concentration of >2.5 mg/L (100% fT>5×MIC, MIC = 0.5 mg/L). Conclusions Critically ill patients show higher unbound flucloxacillin fractions and concentrations than previously thought. Consequently, the risk of subtherapeutic exposure is low.
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Affiliation(s)
- Eveline Wallenburg
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Rob Ter Heine
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Dylan W de Lange
- Department of Intensive Care and Dutch Poisons Information Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Henk van Leeuwen
- Department of Intensive Care, Rijnstate, Arnhem, The Netherlands
| | - Jeroen A Schouten
- Department of Intensive Care, Radboud university medical center, Nijmegen, The Netherlands.,Department of Intensive Care, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands.,Radboudumc Center for Infectious Diseases, Nijmegen, The Netherlands
| | - Jaap Ten Oever
- Radboudumc Center for Infectious Diseases, Nijmegen, The Netherlands.,Department of Internal Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Eva Kolwijck
- Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands
| | - David M Burger
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands.,Radboudumc Center for Infectious Diseases, Nijmegen, The Netherlands
| | - Peter Pickkers
- Department of Intensive Care, Radboud university medical center, Nijmegen, The Netherlands.,Radboudumc Center for Infectious Diseases, Nijmegen, The Netherlands
| | - Emilie M Gieling
- Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Tim Frenzel
- Department of Intensive Care, Radboud university medical center, Nijmegen, The Netherlands
| | - Roger J Brüggemann
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands.,Radboudumc Center for Infectious Diseases, Nijmegen, The Netherlands
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Rubino CM, Flanagan S. Population Pharmacokinetics of Rezafungin in Patients with Fungal Infections. Antimicrob Agents Chemother 2021; 65:e0084221. [PMID: 34398673 PMCID: PMC8522775 DOI: 10.1128/aac.00842-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 08/11/2021] [Indexed: 11/29/2022] Open
Abstract
Rezafungin is a novel antifungal agent of the echinocandin class with potent activity against species of Candida and Aspergillus, including subsets of resistant strains, and Pneumocystis jirovecii. The objective of this analysis was to develop a population pharmacokinetic (PK) model to characterize the disposition of rezafungin in plasma following intravenous (IV) administration in healthy volunteers and in patients with candidemia and/or invasive candidiasis. The population PK model was based on a previous model from phase 1 data; formal covariate analyses were conducted to identify any relationships between subject characteristics and rezafungin PK variability. A four-compartment model with linear elimination and zero-order drug input provided a robust fit to the pooled data. Several statistically significant relationships between subject descriptors (sex, infection status, serum albumin, and body surface area [BSA]) and rezafungin PK parameters were identified, but none were deemed clinically relevant. Previous dose justification analyses conducted using data from phase 1 subjects alone are expected to remain appropriate. The final model provided a precise and unbiased fit to the observed concentrations and can be used to reliably predict rezafungin PK in infected patients.
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Population pharmacokinetics of vancomycin in critically ill adult patients receiving extracorporeal membrane oxygenation (an ASAP ECMO study). Antimicrob Agents Chemother 2021; 66:e0137721. [PMID: 34633852 DOI: 10.1128/aac.01377-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our study aimed to describe the population pharmacokinetics (PK) of vancomycin in critically ill patients receiving extracorporeal membrane oxygenation (ECMO), including those receiving concomitant renal replacement therapy (RRT). Dosing simulations were used to recommend maximally effective and safe dosing regimens. Serial vancomycin plasma concentrations were measured and analysed using a population PK approach on Pmetrics®. The final model was used to identify dosing regimens that achieved target exposures of area under the curve (AUC0-24) of 400 - 700 mg·h/L at steady state. Twenty-two patients were enrolled, of which 11 patients received concomitant RRT. In the non-RRT patients, the median creatinine clearance (CrCL) was 75 mL/min and the mean daily dose of vancomycin was 25.5 mg/kg. Vancomycin was well described in a two-compartment model with CrCL, the presence of RRT and total body weight found as significant predictors of clearance and central volume of distribution (Vc). The mean vancomycin renal clearance and Vc were 3.20 L/h and 29.7 L respectively, while the clearance for patients on RRT was 0.15 L/h. ECMO variables did not improve the final covariate model. We found that recommended dosing regimens for critically ill adult patients not on ECMO can be safely and effectively used in those on ECMO. Loading doses of at least 25 mg/kg followed by maintenance doses of 12.5 - 20 mg/kg 12-hourly are associated with a 97 - 98% probability of efficacy and 11 - 12% probability of toxicity, in patients with normal renal function. Therapeutic drug monitoring along with reductions in dosing are warranted for patients with renal impairment and those with concomitant RRT.
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González-Sales M, Holford N, Bonnefois G, Desrochers J. Wide size dispersion and use of body composition and maturation improves the reliability of allometric exponent estimates. J Pharmacokinet Pharmacodyn 2021; 49:151-165. [PMID: 34609707 DOI: 10.1007/s10928-021-09788-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/26/2021] [Indexed: 11/29/2022]
Abstract
To evaluate study designs and the influence of dispersion of body size, body composition and maturation of clearance or reliable estimation of allometric exponents. Non-linear mixed effects modeling and parametric bootstrap were employed to assess how the study sample size, number of observations per subject, between subject variability (BSV) and dispersion of size distribution affected estimation bias and uncertainty of allometric exponents. The role of covariate model misspecification was investigated using a large data set ranging from neonates to adults. A decrease in study sample size, number of observations per subject, an increase in BSV and a decrease in dispersion of size distribution, increased the uncertainty of allometric exponent estimates. Studies conducted only in adults with drugs exhibiting normal (30%) BSV in clearance may need to include at least 1000 subjects to be able to distinguish between allometric exponents of 2/3 and 1. Nevertheless, studies including both children and adults can distinguish these exponents with only 100 subjects. A marked bias of 45% (95%CI 41-49%) in the estimate of the allometric exponent of clearance was obtained when maturation and body composition were ignored in infants. A wide dispersion of body size (e.g. infants, children and adults) is required to reliably estimate allometric exponents. Ignoring differences in body composition and maturation of clearance may bias the exponent for clearance. Therefore, pharmacometricians should avoid estimating allometric exponent parameters without suitable designs and covariate models. Instead, they are encouraged to rely on the well-developed theory and evidence that clearance and volume parameters in humans scale with theory-based exponents.
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Affiliation(s)
| | - Nick Holford
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
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36
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Taylor WR, Hoglund RM, Peerawaranun P, Nguyen TN, Hien TT, Tarantola A, von Seidlein L, Tripura R, Peto TJ, Dondorp AM, Landier J, H Nosten F, Smithuis F, Phommasone K, Mayxay M, Kheang ST, Say C, Neeraj K, Rithea L, Dysoley L, Kheng S, Muth S, Roca-Feltrer A, Debackere M, Fairhurst RM, Song N, Buchy P, Menard D, White NJ, Tarning J, Mukaka M. Development of weight and age-based dosing of daily primaquine for radical cure of vivax malaria. Malar J 2021; 20:366. [PMID: 34503519 PMCID: PMC8427859 DOI: 10.1186/s12936-021-03886-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In many endemic areas, Plasmodium vivax malaria is predominantly a disease of young adults and children. International recommendations for radical cure recommend fixed target doses of 0.25 or 0.5 mg/kg/day of primaquine for 14 days in glucose-6-phosphate dehydrogenase normal patients of all ages. However, for many anti-malarial drugs, including primaquine, there is evidence that children have lower exposures than adults for the same weight-adjusted dose. The aim of the study was to develop 14-day weight-based and age-based primaquine regimens against high-frequency relapsing tropical P. vivax. METHODS The recommended adult target dose of 0.5 mg/kg/day (30 mg in a 60 kg patient) is highly efficacious against tropical P. vivax and was assumed to produce optimal drug exposure. Primaquine doses were calculated using allometric scaling to derive a weight-based primaquine regimen over a weight range from 5 to 100 kg. Growth curves were constructed from an anthropometric database of 53,467 individuals from the Greater Mekong Subregion (GMS) to define weight-for-age relationships. The median age associated with each weight was used to derive an age-based dosing regimen from the weight-based regimen. RESULTS The proposed weight-based regimen has 5 dosing bands: (i) 5-7 kg, 5 mg, resulting in 0.71-1.0 mg/kg/day; (ii) 8-16 kg, 7.5 mg, 0.47-0.94 mg/kg/day; (iii) 17-40 kg, 15 mg, 0.38-0.88 mg/kg/day; (iv) 41-80 kg, 30 mg, 0.37-0.73 mg/kg/day; and (v) 81-100 kg, 45 mg, 0.45-0.56 mg/kg/day. The corresponding age-based regimen had 4 dosing bands: 6-11 months, 5 mg, 0.43-1.0 mg/kg/day; (ii) 1-5 years, 7.5 mg, 0.35-1.25 mg/kg/day; (iii) 6-14 years, 15 mg, 0.30-1.36 mg/kg/day; and (iv) ≥ 15 years, 30 mg, 0.35-1.07 mg/kg/day. CONCLUSION The proposed weight-based regimen showed less variability around the primaquine dose within each dosing band compared to the age-based regimen and is preferred. Increased dose accuracy could be achieved by additional dosing bands for both regimens. The age-based regimen might not be applicable to regions outside the GMS, which must be based on local anthropometric data. Pharmacokinetic data in small children are needed urgently to inform the proposed regimens.
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Affiliation(s)
- Walter Robert Taylor
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Richard M Hoglund
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Pimnara Peerawaranun
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
| | - Thuy Nhien Nguyen
- Oxford University Clinical Research Unit, Wellcome Trust Major Oversea Programme, Ho Chi Minh City, Vietnam
| | - Tran Tinh Hien
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Oxford University Clinical Research Unit, Wellcome Trust Major Oversea Programme, Ho Chi Minh City, Vietnam
| | - Arnaud Tarantola
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, Phnom Penh, 12201, Cambodia
| | - Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rupam Tripura
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Department of Global Health, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Thomas J Peto
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jordi Landier
- Shoklo Malaria Research Unit, Mae Sot, Thailand
- Aix-Marseille Université, IRD, INSERM, SESSTIM, Marseille, France
| | - Francois H Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Shoklo Malaria Research Unit, Mae Sot, Thailand
| | | | - Koukeo Phommasone
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
- Amsterdam Institute for Global Health & Development, Amsterdam, The Netherlands
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
- Institute of Research and Education Development, University of Health Sciences, Vientiane, Lao PDR
| | - Soy Ty Kheang
- Center for Health and Social Development (HSD), National Institute for Public Health (NIPH) and University Research Co., LLC (URC), Chey Chumneas, Daun Penh, Phnom Penh, Cambodia
- AQUITY Global Inc, 987 Avenel Farm Dr, Potomac, MD, 20854, USA
| | - Chy Say
- Center for Health and Social Development (HSD), National Institute for Public Health (NIPH) and University Research Co., LLC (URC), Chey Chumneas, Daun Penh, Phnom Penh, Cambodia
| | - Kak Neeraj
- University Research Co., LLC Washington DC, 7200 Wisconsin Ave, Bethesda, MD, 20814, USA
| | - Leang Rithea
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
| | - Lek Dysoley
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
- Institute of Public Health, Phnom Penh, Cambodia
| | - Sim Kheng
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
| | - Sinoun Muth
- National Center for Parasitology, Entomology and Malaria Control, Khan Sen Sok, Phnom Penh, Cambodia
| | | | - Mark Debackere
- MSF Belgium Cambodia Malaria Program, Khan Chamkarmon, Phnom Penh, Cambodia
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Ngak Song
- FHI 360 Cambodia Office, Keng Kang III Khan Chamkamon, Phnom Penh, Cambodia
| | - Philippe Buchy
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, Phnom Penh, 12201, Cambodia
- GSK Vaccines, 23 Rochester Park, Singapore, Singapore
| | - Didier Menard
- Institut Pasteur du Cambodge, 5 Monivong Boulevard, Phnom Penh, 12201, Cambodia
- Unité Génétique du Paludisme Et Résistance, Département Parasites Et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/60 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Morse JD, Cortinez LI, Anderson BJ. Pharmacokinetic concepts for dexmedetomidine target-controlled infusion pumps in children. Paediatr Anaesth 2021; 31:924-931. [PMID: 34085357 DOI: 10.1111/pan.14235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/26/2021] [Accepted: 05/31/2021] [Indexed: 12/15/2022]
Abstract
Pharmacokinetic parameter estimates are used in mathematical equations (pharmacokinetic models) to describe concentration changes with time in a population and are specific to that population. Simulation using these models and their parameter estimates can enrich understanding of drug behavior and serve as a basis for study design. Pharmacokinetic concepts are presented pertaining to future designs of dexmedetomidine target-controlled infusion pumps in children. This manuscript provides the pediatric anesthesiologist with an understanding of the nuances that should be considered when using target-controlled infusion pumps; how the central volume may differ between populations, how clearance changes with age, and the impact of adverse effects on dose. In addition, the ideal loading dose and rate of delivery to achieve target concentration without adverse cardiovascular effects are reviewed, and finally, dose considerations for obese children, based on contact-sensitive half-time, are introduced. An understanding of context-sensitive half-time changes with age enables anesthetic practitioners to better estimate duration of effect after cessation of dexmedetomidine infusion. Use of these known pharmacokinetic parameters and covariate information for the pediatric patient could readily be incorporated into commercial target-controlled infusion pumps to allow effective and safe open-loop administration of dexmedetomidine in children.
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Affiliation(s)
- James D Morse
- Department of Pharmacology & Clinical Pharmacology, Auckland University, Auckland, New Zealand
| | - Luis Ignacio Cortinez
- División Anestesiología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago de Chile, Chile
| | - Brian J Anderson
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
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Busse D, Simon P, Petroff D, Dorn C, Schmitt L, Bindellini D, Kratzer A, Dietrich A, Zeitlinger M, Huisinga W, Michelet R, Wrigge H, Kloft C. Similar Piperacillin/Tazobactam Target Attainment in Obese versus Nonobese Patients despite Differences in Interstitial Tissue Fluid Pharmacokinetics. Pharmaceutics 2021; 13:1380. [PMID: 34575456 PMCID: PMC8464843 DOI: 10.3390/pharmaceutics13091380] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/09/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022] Open
Abstract
Precision dosing of piperacillin/tazobactam in obese patients is compromised by sparse information on target-site exposure. We aimed to evaluate the appropriateness of current and alternative piperacillin/tazobactam dosages in obese and nonobese patients. Based on a prospective, controlled clinical trial in 30 surgery patients (15 obese/15 nonobese; 0.5-h infusion of 4 g/0.5 g piperacillin/tazobactam), piperacillin pharmacokinetics were characterized in plasma and at target-site (interstitial fluid of subcutaneous adipose tissue) via population analysis. Thereafter, multiple 3-4-times daily piperacillin/tazobactam short-term/prolonged (recommended by EUCAST) and continuous infusions were evaluated by simulation. Adequacy of therapy was assessed by probability of pharmacokinetic/pharmacodynamic target-attainment (PTA ≥ 90%) based on time unbound piperacillin concentrations exceed the minimum inhibitory concentration (MIC) during 24 h (%fT>MIC). Lower piperacillin target-site maximum concentrations in obese versus nonobese patients were explained by the impact of lean (approximately two thirds) and fat body mass (approximately one third) on volume of distribution. Simulated steady-state concentrations were 1.43-times, 95%CI = (1.27; 1.61), higher in plasma versus target-site, supporting targets of %fT>2×MIC instead of %fT>4×MIC during continuous infusion to avoid target-site concentrations constantly below MIC. In all obesity and renally impairment/hyperfiltration stages, at MIC = 16 mg/L, adequate PTA required prolonged (thrice-daily 4 g/0.5 g over 3.0 h at %fT>MIC = 50) or continuous infusions (24 g/3 g over 24 h following loading dose at %fT>MIC = 98) of piperacillin/tazobactam.
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Affiliation(s)
- David Busse
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, 12169 Berlin, Germany; (D.B.); (L.S.); (D.B.); (R.M.)
- Graduate Research Training Program PharMetrX, 12169 Berlin, Germany
| | - Philipp Simon
- Department of Anesthesiology, Intensive Care, University of Leipzig Medical Centre, 04103 Leipzig, Germany; (P.S.); (A.D.)
- Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, 04103 Leipzig, Germany; (D.P.); (H.W.)
| | - David Petroff
- Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, 04103 Leipzig, Germany; (D.P.); (H.W.)
- Clinical Trial Centre Leipzig, University of Leipzig, 04109 Leipzig, Germany
| | - Christoph Dorn
- Institute of Pharmacy, University of Regensburg, 93053 Regensburg, Germany;
| | - Lisa Schmitt
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, 12169 Berlin, Germany; (D.B.); (L.S.); (D.B.); (R.M.)
- Graduate Research Training Program PharMetrX, 12169 Berlin, Germany
| | - Davide Bindellini
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, 12169 Berlin, Germany; (D.B.); (L.S.); (D.B.); (R.M.)
- Graduate Research Training Program PharMetrX, 12169 Berlin, Germany
| | - Alexander Kratzer
- Hospital Pharmacy, University Hospital Regensburg, 93053 Regensburg, Germany;
| | - Arne Dietrich
- Department of Anesthesiology, Intensive Care, University of Leipzig Medical Centre, 04103 Leipzig, Germany; (P.S.); (A.D.)
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, University Medical University of Vienna, 1090 Vienna, Austria;
| | - Wilhelm Huisinga
- Institute of Mathematics, University of Potsdam, 14469 Potsdam, Germany;
| | - Robin Michelet
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, 12169 Berlin, Germany; (D.B.); (L.S.); (D.B.); (R.M.)
| | - Hermann Wrigge
- Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, 04103 Leipzig, Germany; (D.P.); (H.W.)
- Department of Anesthesiology, Intensive Care and Emergency Medicine, Pain Therapy, Bergmannstrost Hospital Halle, 06112 Halle, Germany
| | - Charlotte Kloft
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin, 12169 Berlin, Germany; (D.B.); (L.S.); (D.B.); (R.M.)
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Ben Hassine K, Nava T, Théoret Y, Nath CE, Daali Y, Kassir N, Lewis V, Bredius RGM, Shaw PJ, Bittencourt H, Krajinovic M, Uppugunduri CRS, Ansari M. Precision dosing of intravenous busulfan in pediatric hematopoietic stem cell transplantation: Results from a multicenter population pharmacokinetic study. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2021; 10:1043-1056. [PMID: 34453497 PMCID: PMC8452291 DOI: 10.1002/psp4.12683] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/14/2021] [Accepted: 06/11/2021] [Indexed: 12/13/2022]
Abstract
Busulfan (Bu) is a common component of conditioning regimens before hematopoietic stem cell transplantation (HSCT) and is known for high interpatient pharmacokinetic (PK) variability. This study aimed to develop and externally validate a multicentric, population PK (PopPK) model for intravenous Bu in pediatric patients before HSCT to first study the influence of glutathione‐s‐transferase A1 (GSTA1) polymorphisms on Bu's PK in a large multicentric pediatric population while accounting for fludarabine (Flu) coadministration and, second, to establish an individualized, model‐based, first‐dose recommendation for intravenous Bu that can be widely used in pediatric patients. The model was built using data from 302 patients from five transplantation centers who received a Bu‐based conditioning regimen. External model validation used data from 100 patients. The relationship between body weight and Bu clearance (CL) was best described by an age‐dependent allometric scaling of a body weight model. A stepwise covariate analysis identified Day 1 of Bu conditioning, GSTA1 metabolic groups based on GSTA1 polymorphisms, and Flu coadministration as significant covariates influencing Bu CL. The final model adequately predicted Bu first‐dose CL in the external cohort, with 81% of predicted area under the curves within the therapeutic window. The final model showed minimal bias (mean prediction error, −0.5%; 95% confidence interval [CI], −3.1% to 2.0%) and acceptable precision (mean absolute prediction error percentage, 18.7%; 95% CI, 17.0%–20.5%) in Bu CL prediction for dosing. This multicentric PopPK study confirmed the influence of GSTA1 polymorphisms and Flu coadministration on Bu CL. The developed model accurately predicted Bu CL and first doses in an external cohort of pediatric patients.
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Affiliation(s)
- Khalil Ben Hassine
- CANSEARCH Research Platform in Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, University of Geneva, Geneva, Switzerland.,Division of Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Tiago Nava
- CANSEARCH Research Platform in Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, University of Geneva, Geneva, Switzerland.,Division of Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Yves Théoret
- Charles-Bruneau Cancer Center, Sainte-Justine University Health Center (SJUHC), Montreal, Quebec, Canada.,Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada.,Clinical Pharmacology Unit, Sainte-Justine University Health Center (SJUHC), Montreal, Quebec, Canada.,Department of Pediatrics, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Christa E Nath
- Department of Biochemistry, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,The Cancer Centre for Children, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Youssef Daali
- Clinical Pharmacology and Toxicology Division, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.,Faculty of Medicine & Sciences, University of Geneva, Geneva, Switzerland
| | - Nastya Kassir
- Genentech/Roche, Clinical Pharmacology, South San Francisco, California, USA
| | - Victor Lewis
- Department of Pediatrics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Robbert G M Bredius
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter J Shaw
- The Cancer Centre for Children, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Henrique Bittencourt
- Charles-Bruneau Cancer Center, Sainte-Justine University Health Center (SJUHC), Montreal, Quebec, Canada.,Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada.,Clinical Pharmacology Unit, Sainte-Justine University Health Center (SJUHC), Montreal, Quebec, Canada.,Department of Pediatrics, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Maja Krajinovic
- Charles-Bruneau Cancer Center, Sainte-Justine University Health Center (SJUHC), Montreal, Quebec, Canada.,Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada.,Clinical Pharmacology Unit, Sainte-Justine University Health Center (SJUHC), Montreal, Quebec, Canada.,Department of Pediatrics, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Chakradhara Rao Satyanarayana Uppugunduri
- CANSEARCH Research Platform in Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, University of Geneva, Geneva, Switzerland.,Division of Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Marc Ansari
- CANSEARCH Research Platform in Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, University of Geneva, Geneva, Switzerland.,Division of Pediatric Oncology and Hematology, Department of Pediatrics, Gynecology and Obstetrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
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Zhu J, Wu YS, Beechinor RJ, Kemper R, Bukkems LH, Mathôt RAA, Cnossen MH, Gonzalez D, Chen SL, Key NS, Crona DJ. Pharmacokinetics of perioperative FVIII in adult patients with haemophilia A: An external validation and development of an alternative population pharmacokinetic model. Haemophilia 2021; 27:974-983. [PMID: 34405493 DOI: 10.1111/hae.14393] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/04/2021] [Accepted: 07/25/2021] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Haemophilia A patients require perioperative clotting factor replacement to limit excessive bleeding. Weight-based dosing of Factor VIII (FVIII) does not account for inter-individual pharmacokinetic (PK) variability, and may lead to suboptimal FVIII exposure. AIM To perform an external validation of a previously developed population PK (popPK) model of perioperative FVIII in haemophilia A patients. METHODS A retrospective chart review identified perioperative haemophilia A patients at the University of North Carolina (UNC) between April 2014 and November 2019. Patient data was used to externally validate a previously published popPK model proposed by Hazendonk. Based on these validation results, a modified popPK model was developed to characterize FVIII PK in our patients. Dosing simulations were performed using this model to compare FVIII target attainment between intermittent bolus (IB) and continuous infusion (CI) administration methods. RESULTS A total of 521 FVIII concentrations, drawn from 34 patients, were analysed. Validation analyses revealed that the Hazendonk model did not fully capture FVIII PK in the UNC cohort. Therefore, a modified one-compartment model, with weight and age as covariates on clearance (CL), was developed. Dosing simulations revealed that CI resulted in improved target attainment by 16%, with reduced overall FVIII usage by 58 IU/kg, compared to IB. CONCLUSION External validation revealed a previously published popPK model of FVIII did not adequately characterize UNC patients, likely due to differences in patient populations. Future prospective studies are needed to evaluate our model prior to implementation into clinical practice.
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Affiliation(s)
- Jing Zhu
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - Yi Shuan Wu
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - Ryan J Beechinor
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA.,Department of Pharmacy, University of California Davis Comprehensive Cancer Center, Sacramento, California, USA
| | - Ryan Kemper
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - Laura H Bukkems
- Hospital Pharmacy, Clinical Pharmacology, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Ron A A Mathôt
- Hospital Pharmacy, Clinical Pharmacology, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Marjon H Cnossen
- Department of Pediatric Hematology, Erasmus University Medical Center, Sophia Children's Hospital, Rotterdam, the Netherlands
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA
| | - Sheh-Li Chen
- Department of Pharmacy, University of North Carolina Hospitals and Clinics, Chapel Hill, North Carolina, USA
| | - Nigel S Key
- Division of Hematology and Blood Research Center, Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Daniel J Crona
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, USA.,Department of Pharmacy, University of North Carolina Hospitals and Clinics, Chapel Hill, North Carolina, USA.,UNC Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
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41
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Leegwater E, Kraaijenbrink BVC, Moes DJAR, Purmer IM, Wilms EB. Population pharmacokinetics of ceftriaxone administered as continuous or intermittent infusion in critically ill patients. J Antimicrob Chemother 2021; 75:1554-1558. [PMID: 32129853 DOI: 10.1093/jac/dkaa067] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES To describe the population pharmacokinetics and protein-binding characteristics of unbound ceftriaxone administered as continuous or intermittent infusion. Additionally, to determine the optimal dosing regimen in critically ill patients. METHODS A pharmacokinetic study was performed in the ICU of a tertiary teaching hospital. Patients were treated with ceftriaxone as continuous or intermittent infusion. A population pharmacokinetic model was developed with non-linear mixed-effects analysis. Subsequently, the PTA of a 100% T>MIC was assessed for influential patient characteristics using Monte Carlo simulation. RESULTS Fifty-five patients were included. The pharmacokinetics of ceftriaxone was best described by a one-compartment model with non-linear saturable protein binding including the following covariates: body weight, estimated CLCR, serum albumin concentration and mode of administration. For pathogens with an MIC of 1 mg/L, the simulation demonstrated that intermittent infusion of 2 g/24 h only resulted in a ≥90% PTA in patients with a reduced CLCR (0-60 mL/min). Intermittent infusion of 2 g/12 h led to sufficient exposure if CLCR was 0-90 mL/min and continuous infusion of 2 g/24 h led to a ≥90% PTA in all simulations (CLCR 0-180 mL/min). CONCLUSIONS In the critically ill, the clearance of unbound ceftriaxone is closely related to CLCR. Furthermore, ceftriaxone protein binding is saturable, variable and dependent on serum albumin concentration. Intermittent dosing of 2 g/24 h ceftriaxone leads to subtherapeutic exposure in patients with a normal or increased CLCR. Treating these patients with continuous infusion of 2 g/24 h is more effective than an intermittent dosing regimen of 2 g/12 h.
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Affiliation(s)
- E Leegwater
- Apotheek Haagse Ziekenhuizen, The Hague, The Netherlands.,Department of Pharmacy, Haga Teaching Hospital, The Hague, The Netherlands
| | - B V C Kraaijenbrink
- Amsterdam University Medical Centers - location VUmc, Amsterdam, The Netherlands
| | - D J A R Moes
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - I M Purmer
- Department of Intensive Care, Haga Teaching Hospital, The Hague, The Netherlands
| | - E B Wilms
- Apotheek Haagse Ziekenhuizen, The Hague, The Netherlands.,Department of Pharmacy, Haga Teaching Hospital, The Hague, The Netherlands
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Francis J, Mngqibisa R, McIlleron H, Kendall MA, Wu X, Dooley KE, Firnhaber C, Godfrey C, Cohn SE, Denti P. A Semimechanistic Pharmacokinetic Model for Depot Medroxyprogesterone Acetate and Drug-Drug Interactions With Antiretroviral and Antituberculosis Treatment. Clin Pharmacol Ther 2021; 110:1057-1065. [PMID: 34151439 PMCID: PMC8449800 DOI: 10.1002/cpt.2324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/19/2021] [Indexed: 11/11/2022]
Abstract
Depot medroxyprogesterone acetate is an injectable hormonal contraceptive, widely used by women of childbearing potential living with HIV and/or tuberculosis. As medroxyprogesterone acetate is a cytochrome P450 (CYP3A4) substrate, drug-drug interactions (DDIs) with antiretroviral or antituberculosis treatment may lead to subtherapeutic medroxyprogesterone acetate concentrations (< 0.1 ng/mL), resulting in contraception failure, when depot medroxyprogesterone is dosed at 12-week intervals. A pooled population pharmacokinetic analysis with 744 plasma medroxyprogesterone acetate concentrations from 138 women treated with depot medroxyprogesterone and antiretroviral/antituberculosis treatment across three clinical trials was performed. Monte Carlo simulations were performed to predict the percentage of participants with subtherapeutic medroxyprogesterone acetate concentrations and to derive alternative dosing strategies. Medroxyprogesterone acetate clearance increased by 24.7% with efavirenz coadministration. Efavirenz plus antituberculosis treatment (rifampicin + isoniazid) increased clearance by 52.4%. Conversely, lopinavir/ritonavir and nelfinavir decreased clearance (28.7% and 15.8%, respectively), but lopinavir/ritonavir also accelerated medroxyprogesterone acetate's appearance into the systemic circulation, thus shortening the terminal half-life. A higher risk of subtherapeutic medroxyprogesterone acetate concentrations at Week 12 was predicted on a typical 60-kg woman on efavirenz (4.99%) and efavirenz with antituberculosis treatment (6.08%) when compared with medroxyprogesterone acetate alone (2.91%). This risk increased in women with higher body weight. Simulations show that re-dosing every 8 to 10 weeks circumvents the risk of subtherapeutic medroxyprogesterone acetate exposure associated with these DDIs. Dosing depot medroxyprogesterone every 8 to 10 weeks should eliminate the risk of subtherapeutic medroxyprogesterone acetate exposure caused by coadministered efavirenz and/or antituberculosis treatment, thus reducing the risk of contraceptive failure.
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Affiliation(s)
- Jose Francis
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Rosie Mngqibisa
- Enhancing Care Foundation, Durban International CRS, Wentworth Hospital, Durban, South Africa
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | | | - Xingye Wu
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Kelly E Dooley
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Cynthia Firnhaber
- Division of Infectious Diseases, Department of Medicine, Anschutz Medical Center, University of Colorado, Aurora, Colorado, USA
| | - Catherine Godfrey
- Division of AIDS, National Institutes of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Susan E Cohn
- Division of Infectious Diseases, Department of Medicine, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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Prospective Cohort Study of Micafungin Population Pharmacokinetic Analysis in Plasma and Peritoneal Fluid in Septic Patients with Intra-abdominal Infections. Antimicrob Agents Chemother 2021; 65:e0230720. [PMID: 33846133 DOI: 10.1128/aac.02307-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The objective of this study was to describe the pharmacokinetics (PK) of micafungin in plasma and peritoneal fluid in septic patients with intra-abdominal infections. Twelve patients with secondary peritonitis in septic shock receiving 100 mg micafungin once daily were included. Total micafungin plasma and peritoneal fluid were subjected to a population pharmacokinetic analysis using Pmetrics. Monte Carlo simulations were performed considering the total area under the curve from 0 to 24 h (AUC0-24)/MIC ratios in plasma. Micafungin concentrations in both plasma and the peritoneal exudate were best described by a three-compartmental PK model with the fat-free mass (FFM) as a covariate of clearance (CL) and the volume of the central compartment (Vc). The mean parameter estimates (standard deviations [SD]) were 1.18 (0.40) liters/h for CL and 12.85 (4.78) liters for Vc. The mean peritoneal exudate/plasma ratios (SD) of micafungin were 25% (5%) on day 1 and 40% (8%) between days 3 and 5. Dosing simulations supported the use of standard 100-mg daily dosing for Candida albicans (FFM, <60 kg), C. glabrata (FFM, <50 kg), and C. tropicalis (FFM, <30 kg) on the second day of therapy. There is a moderate penetration of micafungin into the peritoneal cavity (25 to 40%). For empirical treatment, a dose escalation of at least a loading dose of 150 mg depending on the FFM of patients and the Candida species is suggested to be effective from the first day of therapy.
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Ogami C, Tsuji Y, Seki H, Kawano H, To H, Matsumoto Y, Hosono H. An artificial neural network-pharmacokinetic model and its interpretation using Shapley additive explanations. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2021; 10:760-768. [PMID: 33955705 PMCID: PMC8302242 DOI: 10.1002/psp4.12643] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/23/2021] [Accepted: 04/19/2021] [Indexed: 12/20/2022]
Abstract
We developed a method to apply artificial neural networks (ANNs) for predicting time‐series pharmacokinetics (PKs), and an interpretable the ANN‐PK model, which can explain the evidence of prediction by applying Shapley additive explanations (SHAP). A previous population PK (PopPK) model of cyclosporin A was used as the comparison model. The patients’ data were used for the ANN‐PK model input, and the output by ANN was the clearance (CL). The estimated CL value from the ANN were substituted into the one‐compartment with one‐order absorption model, the concentrations were calculated, and the parameters of ANN were updated by the back‐propagation method. Kernel SHAP was applied to the trained model and the SHAP value of each input was calculated. The root mean squared error for the PopPK model and the ANN‐PK model were 41.1 and 31.0 ng/ml, respectively. The goodness of fit plots for the ANN‐PK model represented more convergence to y = x compared with that for the PopPK model, with good model performance for the ANN‐PK model. The most influential factors on CL output were age and body weight from the evaluation using Kernel SHAP, and these factors were incorporated into the PopPK model as the significant covariates of CL. The ANN‐PK model could handle time‐series data and showed higher prediction accuracy then the conventional PopPK model, and the scientific validity for the model could be evaluated by applying SHAP. Study Highlights WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?
A black‐box property of an artificial neural network (ANN) decreases the scientific confidence of the model, and making it difficult to utilize the ANN in the medical field. Moreover, difficulty in handling the time‐series data is a significant problem for applying the ANN for pharmacometrics study.
WHAT QUESTION DID THIS STUDY ADDRESS?
How can we apply the ANN for predicting the time‐series pharmacokinetics (PKs) , and confirm the scientific validity of the ANN model?
WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?
Using the ANN in combination with a conventional compartment (ANN‐PK) model enabled to handle the time‐series PK data, and the predicting performance of the model was higher than that of the population PK model. Furthermore, we could evaluate the scientific validity of the ANN model by applying the Shapley additive explanations.
HOW MIGHT THIS CHANGE DRUG DISCOVERY, DEVELOPMENT, AND/OR THERAPEUTICS?
We expect that our study will contribute to develop the interpretable ANN model, which can predict the time‐series PKs, drug efficacies, and side effects with high prediction performance.
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Affiliation(s)
- Chika Ogami
- Department of Medical Pharmaceutics, Graduate School of Medical and Pharmaceutical Sciences for Research, University of Toyama, Toyama, Japan.,Center for Pharmacist Education, School of Pharmacy, Nihon University, Chiba, Japan
| | - Yasuhiro Tsuji
- Center for Pharmacist Education, School of Pharmacy, Nihon University, Chiba, Japan
| | - Hiroto Seki
- Department of Computer Engineering, College of Science and Technology, Nihon University, Chiba, Japan
| | - Hideaki Kawano
- Faculty of Engineering, Kyushu Institute of Technology, Fukuoka, Japan
| | - Hideto To
- Department of Medical Pharmaceutics, Graduate School of Medical and Pharmaceutical Sciences for Research, University of Toyama, Toyama, Japan
| | - Yoshiaki Matsumoto
- Laboratory of Clinical Pharmacokinetics, School of Pharmacy, Nihon University, Chiba, Japan
| | - Hiroyuki Hosono
- Department of Computer Engineering, College of Science and Technology, Nihon University, Chiba, Japan
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Janek E, Edl D, Taflinski A, Talakic E, Adelsmayr G, Janisch M, Igrec J, Quehenberger F, Fuchsjäger M, Schöllnast H. Contrast media dose adjustment to allometric parameters of body mass in multiphasic CT of the liver: A comparison of different metrics. Eur J Radiol 2021; 141:109778. [PMID: 34174486 DOI: 10.1016/j.ejrad.2021.109778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/13/2021] [Accepted: 05/16/2021] [Indexed: 11/15/2022]
Abstract
PURPOSE To assess correlations of lean body weight (LBW) calculated with various formulas, total body weight (TBW), body height (BH), body mass index (BMI), body surface area (BSA) and fat-free mass (FFM) with vascular and parenchymal enhancement in multiphasic CT of the liver. METHOD Thirty consecutive patients underwent multiphasic CT of the liver using constant iodine dose and flow rate. Contrast enhancement of aorta, portal vein and liver was calculated by measuring mean vascular and parenchymal attenuation in pre-contrast and post-contrast phases. Correlations of TBW, BH, BMI, BSA, FFM, and LBW (calculated with formulas of Boer, Hume, James and Green&Duffull) with enhancement were tested using Spearman's correlation coefficient. The method of Fieller et al. was used to calculate 95 % confidence intervals. A p-value ≤ 0.05 was considered statistically significant. RESULTS Aortal enhancement correlated strongly with TBW, BSA, LBWBoer and LBWHume and moderately with BH, BMI, FFM, LBWJames and LBWGreen&Duffull. Liver enhancement in the late arterial phase correlated moderately with TBW, FFM, LBWBoer, LBWHume and LBWGreen&Duffull and weakly with BSA. Liver enhancement in the portal venous phase correlated strongly with TBW, BSA, FFM, LBWBoer, LBWHume and LBWGreen&Duffull, whereby overlap of the 95 % CI graphs demonstrated that the differences in the correlation coefficients were not statistically significant. Liver enhancement in the delayed phase correlated moderately with BH but did not correlate significantly with any other parameter. CONCLUSION Regardless of the form used for calculation, LBW did not correlate statistically significantly stronger than TBW with vascular or parenchymal enhancement of the liver.
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Affiliation(s)
- Elmar Janek
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Dominik Edl
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Adrian Taflinski
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Emina Talakic
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Gabriel Adelsmayr
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Michael Janisch
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Jasminka Igrec
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria
| | - Franz Quehenberger
- Institute of Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Michael Fuchsjäger
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria.
| | - Helmut Schöllnast
- Division of General Radiology, Department of Radiology, Medical University of Graz, Graz, Austria; Institute of Radiology, LKH Graz II, Graz, Austria
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Wasmann RE, Svensson EM, Schalkwijk SJ, Brüggemann RJ, Ter Heine R. Normal fat mass cannot be reliably estimated in typical pharmacokinetic studies. Eur J Clin Pharmacol 2021; 77:727-733. [PMID: 33205282 PMCID: PMC8032617 DOI: 10.1007/s00228-020-03042-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/09/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE An influential covariate for pharmacokinetics is (body) size. Recently, the method of estimation of normal fat mass (NFM) has been advocated. Here, the relative contribution of fat mass, estimated as a fraction fat (Ffat), is used to explain differences in pharmacokinetic parameters. This concept is more and more applied. However, it remains unclear whether NFM can be reliably estimated in these typical studies. METHODS We performed an evaluation of the reliability of NFM estimation in a typical study size (n = 30), otherwise best-case scenario, by means of a pharmacokinetic simulation study. Several values of Ffat were investigated. RESULTS In a typical pharmacokinetic study, high imprecision was observed for NFM parameter estimates over a range of scenarios. For example, in a scenario where the true value of Ffat on clearance was 0.5, we found a 95% confidence interval of - 0.1 to 2.1, demonstrating a low precision. The implications for practice are that one could conclude that fat-free mass best describes the relationship of the pharmacokinetics with body size, while the true relationship was between fat-free mass and total body weight. Consequently, this could lead to incorrect extrapolation of pharmacokinetics to extreme body sizes. CONCLUSION In typical pharmacokinetic studies, NFM should be used with caution because the Ffat estimates have low precision. The estimation of Ffat should always be preceded by careful study design evaluation before planning a study, to ensure that the design and sample size is sufficient to apply this potentially useful methodology.
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Affiliation(s)
- Roeland E Wasmann
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6500 HB, Nijmegen, The Netherlands.
| | - Elin M Svensson
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6500 HB, Nijmegen, The Netherlands
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Stein J Schalkwijk
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6500 HB, Nijmegen, The Netherlands
| | - Roger J Brüggemann
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6500 HB, Nijmegen, The Netherlands
| | - Rob Ter Heine
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6500 HB, Nijmegen, The Netherlands
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Hui KHM, Lam HS, Chow CHT, Li YSJ, Leung PHT, Chan LYB, Lee CP, Ewig CLY, Cheung YT, Lam TNT. Personalized Dosing of Intravenous Vancomycin Among Critically Ill Neonates in Hong Kong: Harnessing Electronic Health Records to Develop a Web-Based Dosing Interface (Preprint). JMIR Med Inform 2021; 10:e29458. [PMID: 35099393 PMCID: PMC8844994 DOI: 10.2196/29458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/06/2021] [Accepted: 01/02/2022] [Indexed: 11/15/2022] Open
Abstract
Background Intravenous (IV) vancomycin is used in the treatment of severe infection in neonates. However, its efficacy is compromised by elevated risks of acute kidney injury. The risk is even higher among neonates admitted to the neonatal intensive care unit (NICU), in whom the pharmacokinetics of vancomycin vary widely. Therapeutic drug monitoring is an integral part of vancomycin treatment to balance efficacy against toxicity. It involves individual dose adjustments based on the observed serum vancomycin concentration (VCs). However, the existing trough-based approach shows poor evidence for clinical benefits. The updated clinical practice guideline recommends population pharmacokinetic (popPK) model–based approaches, targeting area under curve, preferably through the Bayesian approach. Since Bayesian methods cannot be performed manually and require specialized computer programs, there is a need to provide clinicians with a user-friendly interface to facilitate accurate personalized dosing recommendations for vancomycin in critically ill neonates. Objective We used medical data from electronic health records (EHRs) to develop a popPK model and subsequently build a web-based interface to perform model-based individual dose optimization of IV vancomycin for NICU patients in local medical institutions. Methods Medical data of subjects prescribed IV vancomycin in the NICUs of Prince of Wales Hospital and Queen Elizabeth Hospital in Hong Kong were extracted from EHRs, namely the Clinical Information System, In-Patient Medication Order Entry, and electronic Patient Record. Patient demographics, such as body weight and postmenstrual age (PMA), serum creatinine (SCr), vancomycin administration records, and VCs were collected. The popPK model employed a 2-compartment infusion model. Various covariate models were tested against body weight, PMA, and SCr, and were evaluated for the best goodness of fit. A previously published web-based dosing interface was adapted to develop the interface in this study. Results The final data set included EHR data extracted from 207 subjects, with a total of 689 VCs measurements. The final model chosen explained 82% of the variability in vancomycin clearance. All parameter estimates were within the bootstrapping CIs. Predictive plots, residual plots, and visual predictive checks demonstrated good model predictability. Model approximations showed that the model-based Bayesian approach consistently promoted a probability of target attainment (PTA) above 75% for all subjects, while only half of the subjects could achieve a PTA over 50% with the trough-based approach. The dosing interface was developed with the capability to optimize individual doses with the model-based empirical or Bayesian approach. Conclusions Using EHRs, a satisfactory popPK model was verified and adopted to develop a web-based individual dose optimization interface. The interface is expected to improve treatment outcomes of IV vancomycin for severe infections among critically ill neonates. This study provides the foundation for a cohort study to demonstrate the utility of the new approach compared with previous dosing methods.
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Affiliation(s)
- Ka Ho Matthew Hui
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Hugh Simon Lam
- Department of Paediatrics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Cheuk Hin Twinny Chow
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Yuen Shun Janice Li
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Pok Him Tom Leung
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Long Yin Brian Chan
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Chui Ping Lee
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
- Department of Pharmacy, Prince of Wales Hospital, Hospital Authority, Hong Kong, Hong Kong
| | - Celeste Lom Ying Ewig
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
- Department of Pharmacy, Prince of Wales Hospital, Hospital Authority, Hong Kong, Hong Kong
| | - Yin Ting Cheung
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Tai Ning Teddy Lam
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong
- Department of Pharmacy, Prince of Wales Hospital, Hospital Authority, Hong Kong, Hong Kong
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Model-Based Estimation of Iohexol Plasma Clearance for Pragmatic Renal Function Determination in the Renal Transplantation Setting. Clin Pharmacokinet 2021; 60:1201-1215. [PMID: 33864239 PMCID: PMC8417017 DOI: 10.1007/s40262-021-00998-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2021] [Indexed: 10/26/2022]
Abstract
BACKGROUND Iohexol plasma clearance-based glomerular filtration rate (GFR) determination provides an accurate method for renal function evaluation. This technique is increasingly advocated for clinical situations that dictate highly accurate renal function assessment, as an alternative to conventional serum creatinine-based methods with limited accuracy or poor feasibility. In the renal transplantation setting, this particularly applies to living renal transplant donor eligibility screening, renal transplant function monitoring and research purposes. The dependency of current iohexol GFR estimation techniques on extensive sampling, however, has limited its clinical application. We developed a population pharmacokinetic model and limited sampling schedules, implemented in the online InsightRX precision dosing platform, to facilitate pragmatic iohexol GFR assessment. METHODS Iohexol concentrations (n = 587) drawn 5 min to 4 h after administration were available from 67 renal transplant recipients and 41 living renal transplant donor candidates with measured iohexol GFRs of 27-117 mL/min/1.73 m2. These were split into a model development (n = 72) cohort and an internal validation (n = 36) cohort. External validation was performed with 1040 iohexol concentrations from 268 renal transplant recipients drawn between 5 min and 4 h after administration, and extended iohexol curves up to 24 h from 11 random patients with impaired renal function. Limited sampling schedules based on one to four blood draws within 4 h after iohexol administration were evaluated in terms of bias and imprecision, using the mean relative prediction error and mean absolute relative prediction error. The total deviation index and percentage of limited sampling schedule-based GFR predictions within ± 10% of those of the full model (P10) were assessed to aid interpretation. RESULTS Iohexol pharmacokinetics was best described with a two-compartmental first-order elimination model, allometrically scaled to fat-free mass, with patient type as a covariate on clearance and the central distribution volume. Model validity was confirmed during the internal and external validation. Various limited sampling schedules based on three to four blood draws within 4 h showed excellent predictive performance (mean relative prediction error < ± 0.5%, mean absolute relative prediction error < 3.5%, total deviation index < 5.5%, P10 > 97%). The best limited sampling schedules based on three to four blood draws within 3 h showed reduced predictive performance (mean relative prediction error < ± 0.75%, mean absolute relative prediction error < 5.5%, total deviation index < 9.5%, P10 ≥ 85%), but may be considered for their enhanced clinical feasibility when deemed justified. CONCLUSIONS Our online pharmacometric tool provides an accurate, pragmatic, and ready-to-use technique for measured GFR-based renal function evaluation for clinical situations where conventional methods lack accuracy or show limited feasibility. Additional adaptation and validation of our model and limited sampling schedules for renal transplant recipients with GFRs below 30 mL/min is warranted before considering this technique in these patients.
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Green TP, Binns HJ, Wu H, Ariza AJ, Perrin EM, Quadri M, Hornik CP, Cohen‐Wolkowiez M. Estimation of Body Fat Percentage for Clinical Pharmacokinetic Studies in Children. Clin Transl Sci 2021; 14:509-517. [PMID: 33142010 PMCID: PMC7993323 DOI: 10.1111/cts.12896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/31/2020] [Indexed: 12/19/2022] Open
Abstract
Obesity is a prevalent childhood condition and the degree of adiposity appears likely to be an important covariate in the pharmacokinetics (PKs) of many drugs. We undertook these studies to facilitate the evaluation and, where appropriate, quantification of the covariate effect of body fat percentage (BF%) on PK parameters in children. We examined two large databases to determine the values and variabilities of BF% in children with healthy body weights and in those with obesity, comparing the accuracy and precision of BF% estimation by both clinical methods and demographically derived techniques. Additionally, we conducted simulation studies to evaluate the utility of the several methods for application in clinical trials. BF% was correlated with body mass index (BMI), but was highly variable among both children with healthy body weights and those with obesity. Bio-impedance and several demographically derived techniques produced mean estimates of BF% that differed from dual x-ray absorptiometry by < 1% (accuracy) and a SD of 5% or less (precision). Simulation studies confirmed that when the differences in precision among the several methods were small compared with unexplained between-subject variability of a PK parameter, the techniques were of similar value in assessing the contribution of BF%, if any, as a covariate for that PK parameter. The combination of sex and obesity stage explained 68% of the variance of BF% with BMI. The estimation of BF% from sex and obesity stage can routinely be applied to PK clinical trials to evaluate the contribution of BF% as a potential covariate.
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Affiliation(s)
- Thomas P. Green
- Department of PediatricsAnn & Robert H. Lurie Children's Hospital of Chicago and Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Helen J. Binns
- Department of PediatricsAnn & Robert H. Lurie Children's Hospital of Chicago and Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
- Center on Obesity Management and PreventionStanley Manne Children's Research InstituteChicagoIllinoisUSA
- Department of Preventive MedicineFeinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Huali Wu
- Duke Clinical Research InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Adolfo J. Ariza
- Department of PediatricsAnn & Robert H. Lurie Children's Hospital of Chicago and Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
- Center on Obesity Management and PreventionStanley Manne Children's Research InstituteChicagoIllinoisUSA
| | - Eliana M. Perrin
- Duke Center for Childhood Obesity Research and Division of Primary CareDepartment of PediatricsDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Maheen Quadri
- Department of PediatricsAnn & Robert H. Lurie Children's Hospital of Chicago and Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
- Center on Obesity Management and PreventionStanley Manne Children's Research InstituteChicagoIllinoisUSA
| | - Christoph P. Hornik
- Duke Clinical Research InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
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Seurat J, Girard P, Goteti K, Mentré F. Comparison of Various Phase I Combination Therapy Designs in Oncology for Evaluation of Early Tumor Shrinkage Using Simulations. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2020; 9:686-694. [PMID: 33080100 PMCID: PMC7762808 DOI: 10.1002/psp4.12564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/21/2020] [Indexed: 12/11/2022]
Abstract
There is still a lack of efficient designs for identifying the dose response in oncology combination therapies in early clinical trials. The concentration response relationship can be identified using the early tumor shrinkage time course, which has been shown to be a good early response marker of clinical efficacy. The performance of various designs using an exposure–tumor growth inhibition model was explored using simulations. Different combination effects of new drug M and cetuximab (reference therapy) were explored first assuming no effect of M on cetuximab (to investigate the type I error (α)), and subsequently assuming additivity or synergy between cetuximab and M. One‐arm, two‐arm, and four‐arm designs were evaluated. In the one‐arm design, 60 patients received cetuximab + M. In the two‐arm design, 30 patients received cetuximab and 30 received cetuximab + M. In the four‐arm design, in addition to cetuximab and cetuximab + M as standard doses, combination arms with lower doses of cetuximab were evaluated (15 patients/arm). Model‐based predictions or “simulated observations” of early tumor shrinkage at week 8 (ETS8) were compared between the different arms. With the same number of individuals, the one‐arm design showed better statistical power than other designs but led to strong inflation of α in case of misestimated reference for ETS8 value. The two‐arm design protected against this misestimation and, with the same total number of subjects, would provide higher statistical power than a four‐arm design. However, a four‐arm design would be helpful for exploring more doses of cetuximab in combination with M to better understand the interaction.
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Affiliation(s)
- Jérémy Seurat
- Université de Paris, INSERM, IAME, F-75006 Paris, France
| | - Pascal Girard
- Merck Institute for Pharmacometrics, Merck Serono S.A, Lausanne, Switzerland
| | | | - France Mentré
- Université de Paris, INSERM, IAME, F-75006 Paris, France
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