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Ayuso M, Buyssens L, Stroe M, Valenzuela A, Allegaert K, Smits A, Annaert P, Mulder A, Carpentier S, Van Ginneken C, Van Cruchten S. The Neonatal and Juvenile Pig in Pediatric Drug Discovery and Development. Pharmaceutics 2020; 13:44. [PMID: 33396805 PMCID: PMC7823749 DOI: 10.3390/pharmaceutics13010044] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 02/06/2023] Open
Abstract
Pharmacotherapy in pediatric patients is challenging in view of the maturation of organ systems and processes that affect pharmacokinetics and pharmacodynamics. Especially for the youngest age groups and for pediatric-only indications, neonatal and juvenile animal models can be useful to assess drug safety and to better understand the mechanisms of diseases or conditions. In this respect, the use of neonatal and juvenile pigs in the field of pediatric drug discovery and development is promising, although still limited at this point. This review summarizes the comparative postnatal development of pigs and humans and discusses the advantages of the juvenile pig in view of developmental pharmacology, pediatric diseases, drug discovery and drug safety testing. Furthermore, limitations and unexplored aspects of this large animal model are covered. At this point in time, the potential of the neonatal and juvenile pig as nonclinical safety models for pediatric drug development is underexplored.
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Affiliation(s)
- Miriam Ayuso
- Comparative Perinatal Development, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (M.S.); (A.V.); (C.V.G.)
| | - Laura Buyssens
- Comparative Perinatal Development, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (M.S.); (A.V.); (C.V.G.)
| | - Marina Stroe
- Comparative Perinatal Development, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (M.S.); (A.V.); (C.V.G.)
| | - Allan Valenzuela
- Comparative Perinatal Development, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (M.S.); (A.V.); (C.V.G.)
| | - Karel Allegaert
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium; (K.A.); (P.A.)
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium;
- Department of Hospital Pharmacy, Erasmus MC Rotterdam, 3000 CA Rotterdam, The Netherlands
| | - Anne Smits
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium;
- Neonatal Intensive Care Unit, University Hospitals UZ Leuven, 3000 Leuven, Belgium
| | - Pieter Annaert
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium; (K.A.); (P.A.)
| | - Antonius Mulder
- Department of Neonatology, University Hospital Antwerp, 2650 Edegem, Belgium;
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, 2610 Wilrijk, Belgium
| | | | - Chris Van Ginneken
- Comparative Perinatal Development, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (M.S.); (A.V.); (C.V.G.)
| | - Steven Van Cruchten
- Comparative Perinatal Development, Department of Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium; (L.B.); (M.S.); (A.V.); (C.V.G.)
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Khalil F, Choi SL, Watson E, Tzschentke TM, Lefeber C, Eerdekens M, Freijer J. Population Pharmacokinetics of Tapentadol in Children from Birth to <18 Years Old. J Pain Res 2020; 13:3107-3123. [PMID: 33262645 PMCID: PMC7700087 DOI: 10.2147/jpr.s269549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE The main aim of this analysis was to characterize the pharmacokinetics (PK) of tapentadol in pediatric patients from birth to <18 years old who experience acute pain, requiring treatment with an opioid analgesic. PATIENTS AND METHODS Data from four clinical trials and 148 pediatric patients who received a single dose of tapentadol oral or intravenous solution were included. Population PK analysis was performed to determine the contribution of size-related (bodyweight) and function-related (maturation) factors to the changes in oral bioavailability (F), volume of distribution (V), and clearance (CL) with age. Simulations were carried out to compare pediatric exposures to reference adult values. RESULTS A one-compartment model with allometric scaling on disposition parameters (using theoretical or estimated exponents) and maturation functions on CL and F best described tapentadol PK. The estimated allometric exponents for CL (0.603) and V (0.820) differed slightly from the theoretical values of 0.75 for CL and 1 for V. A maximum in CL/F was observed at about 2-3 years when expressed on a bodyweight basis. Results for younger children as well as the F estimate were sensitive to the scaling approach, but CL/F and V/F as a function of age for the two scaling approaches led to similar curves within the bioequivalence range except below 5 weeks of age. Model-based simulations indicated that the doses used in the included clinical trials lead to exposures within the lower half of the targeted adult exposure. CONCLUSION The development of tapentadol is one of the first examples following a systematic approach for analgesic drug development for children. Our analysis enabled a full characterization and robust understanding of tapentadol PK in children from birth to <18 years, including preterm infants, and showed the importance of evaluating the sensitivity of the inferences of the PK parameters to the selected scaling approach.
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Sandra L, Smits A, Allegaert K, Nicolaï J, Annaert P, Bouillon T. Population pharmacokinetics of propofol in neonates and infants: Gestational and postnatal age to determine clearance maturation. Br J Clin Pharmacol 2020; 87:2089-2097. [PMID: 33085795 DOI: 10.1111/bcp.14620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/31/2020] [Accepted: 09/12/2020] [Indexed: 11/28/2022] Open
Abstract
AIMS Develop a population pharmacokinetic model describing propofol pharmacokinetics in (pre)term neonates and infants, that can be used for precision dosing (e.g. during target-controlled infusion) of propofol in this population. METHODS A nonlinear mixed effects pharmacokinetic analysis (Monolix 2018R2) was performed, based on a pooled study population in 107 (pre)term neonates and infants. RESULTS In total, 836 blood samples were collected from 66 (pre)term neonates and 41 infants originating from 3 studies. Body weight (BW) of the pooled study population was 3.050 (0.580-11.440) kg, postmenstrual age (PMA) was 36.56 (27.00-43.00) weeks and postnatal age (PNA) was 1.14 (0-104.00) weeks (median and min-max range). A 3-compartment structural model was identified and the effect of BW was modelled using fixed allometric exponents. Elimination clearance maturation was modelled accounting for the maturational effect on elimination clearance until birth (by gestational age [GA]) and postpartum (by PNA and GA). The extrapolated adult (70 kg) population propofol elimination clearance (1.64 L min-1 , estimated relative standard error = 6.02%) is in line with estimates from previous population pharmacokinetic studies. Empirical scaling of BW on the central distribution volume in function of PNA improved the model fit. CONCLUSIONS It is recommended to describe elimination clearance maturation by GA and PNA instead of PMA on top of size effects when analyzing propofol pharmacokinetics in populations including preterm neonates. Changes in body composition in addition to weight changes or other physio-anatomical changes may explain the changes in central distribution volume. The developed model may serve as a prior for propofol dose finding and target-controlled infusion in (preterm) neonates.
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Affiliation(s)
- Louis Sandra
- Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Anne Smits
- KU Leuven Department of Development and Regeneration, Leuven, Belgium.,Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | - Karel Allegaert
- KU Leuven Department of Development and Regeneration, Leuven, Belgium.,Division of Clinical Pharmacy, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Johan Nicolaï
- Development Science, UCB BioPharma SPRL, Braine-l'Alleud, Belgium
| | - Pieter Annaert
- Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Thomas Bouillon
- Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium.,Bionotus, Niel, Belgium
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Castineiras D, Armitage L, Lamas LP, De Baere S, Croubels S, Pelligand L. Perioperative pharmacokinetics and pharmacodynamics of meloxicam in emus (Dromaius novaehollandiae) of different age groups using nonlinear mixed effect modelling. J Vet Pharmacol Ther 2020; 44:603-618. [PMID: 33141479 DOI: 10.1111/jvp.12923] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/08/2020] [Accepted: 10/07/2020] [Indexed: 01/19/2023]
Abstract
Meloxicam is a widely used nonsteroidal anti-inflammatory drug in avian species. However, variability in pharmacokinetic (PK) and pharmacodynamic (PD) parameters in birds warrants species-specific studies for dose and dosing interval optimization. We performed a perioperative PK study of meloxicam (0.5 mg/kg, intravenously) on emus of three different age groups: 3 chicks (5 weeks old, 3.5 kg), 4 juveniles (26 weeks old, 18.8 kg) and 6 adults (66 weeks old, 38.8 kg). A two-compartment population PK model including weight as a significant covariate on clearance and central volume of distribution (V1) best fitted the data. The typical values (20 kg bird) for clearance and V1 were 0.54 L/kg/h and 0.095 L/kg. Both parameters significantly decreased with increasing weight/age. Meloxicam potency and selectivity for COX-1 and COX-2 were measured in whole blood assays (TxB2 production endpoint). Meloxicam was partially selective in emus (IC50 COX-1:COX-2 = 9.1:1). At the current empirical dose (0.5 mg/kg/24 hr), plasma meloxicam concentration is above IC50 of COX-2 for only 2 hr. PK/PD predicted dose required for 80% COX-2 inhibition over 24 hr were 3.4, 1.4 and 0.95 L/kg/day in chicks, juveniles and adult emus, respectively. The safety, therapeutic efficacy and practicality of modifying the daily dose or dose interval should be considered for dose recommendations in emus.
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Affiliation(s)
- Diego Castineiras
- Department of Clinical Services and Sciences, Royal Veterinary College, London, UK
| | - Lucy Armitage
- Department of Clinical Services and Sciences, Royal Veterinary College, London, UK
| | - Luís Pardon Lamas
- Structure & Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Siegrid De Baere
- Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Siska Croubels
- Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Ludovic Pelligand
- Department of Clinical Services and Sciences, Royal Veterinary College, London, UK.,Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
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Aulin LBS, De Paepe P, Dhont E, de Jaeger A, Vande Walle J, Vandenberghe W, McWhinney BC, Ungerer JPJ, van Hasselt JGC, De Cock PAJG. Population Pharmacokinetics of Unbound and Total Teicoplanin in Critically Ill Pediatric Patients. Clin Pharmacokinet 2020; 60:353-363. [PMID: 33030704 DOI: 10.1007/s40262-020-00945-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Teicoplanin is a highly protein-bound antibiotic, increasingly used to treat serious Gram-positive infections in critically ill children. Maturational and pathophysiological intensive care unit-related changes often lead to altered pharmacokinetics. In this study, the objectives were to develop a pediatric population-pharmacokinetic model of unbound and total teicoplanin concentrations, to investigate the impact of plasma albumin levels and renal function on teicoplanin pharmacokinetics, and to evaluate the efficacy of the current weight-based dosing regimen. METHODS An observational pharmacokinetic study was performed and blood samples were collected for quantification of unbound and total concentrations of teicoplanin after the first dose and in assumed steady-state conditions. A population-pharmacokinetic analysis was conducted using a standard sequential approach and Monte Carlo simulations were performed for a probability of target attainment analysis using previously published pharmacokinetic-pharmacodynamic targets. RESULTS A two-compartment model with allometric scaling of pharmacokinetic parameters and non-linear plasma protein binding best described the data. Neither the inclusion of albumin nor the renal function significantly improved the model and no other covariates were supported for inclusion in the final model. The probability of target attainment analysis showed that the standard dosing regimen does not satisfactory attain the majority of the proposed targets. CONCLUSIONS We successfully characterized the pharmacokinetics of unbound and total teicoplanin in critically ill pediatric patients. The highly variable unbound fraction of teicoplanin could not be predicted using albumin levels, which may support the use of therapeutic drug monitoring of unbound concentrations. Poor target attainment was shown for the most commonly used dosing regimen, regardless of the pharmacokinetic-pharmacodynamic target evaluated.
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Affiliation(s)
- L B S Aulin
- Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - P De Paepe
- Heymans Institute of Pharmacology, Ghent University, Ghent, Belgium
| | - E Dhont
- Department of Pediatric Intensive Care, Ghent University Hospital, Ghent, Belgium
| | - A de Jaeger
- Department of Pediatric Intensive Care, Ghent University Hospital, Ghent, Belgium
| | - J Vande Walle
- Department of Pediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - W Vandenberghe
- Department of Pediatric Intensive Care, Ghent University Hospital, Ghent, Belgium
| | - B C McWhinney
- Department of Chemical Pathology, Pathology Queensland, Brisbane, QLD, Australia
| | - J P J Ungerer
- Department of Chemical Pathology, Pathology Queensland, Brisbane, QLD, Australia.,School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - J G C van Hasselt
- Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - P A J G De Cock
- Heymans Institute of Pharmacology, Ghent University, Ghent, Belgium. .,Department of Pediatric Intensive Care, Ghent University Hospital, Ghent, Belgium. .,Department of Pharmacy, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
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Kim EH, Lee JH, Kim HS, Jang YE, Ji SH, Kim WH, Kwak JG, Kim JT. Effects of intraoperative dexmedetomidine on the incidence of acute kidney injury in pediatric cardiac surgery patients: A randomized controlled trial. Paediatr Anaesth 2020; 30:1132-1138. [PMID: 32780926 DOI: 10.1111/pan.13995] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 12/29/2022]
Abstract
BACKGROUND Perioperative dexmedetomidine use has been reported to reduce the incidence of postoperative acute kidney injury after adult cardiac surgery. However, large-scale randomized controlled trials evaluating the effect of dexmedetomidine use on acute kidney injury in pediatric patients are lacking. AIMS We investigated whether intraoperative dexmedetomidine could reduce the incidence of acute kidney injury in pediatric cardiac surgery patients. METHODS In total, 141 pediatric patients were randomly assigned to dexmedetomidine or control groups. After anesthetic induction, patients in the dexmedetomidine group were administered 1 µg/kg of dexmedetomidine over 10 minutes and an additional 0.5 µg/kg/h of dexmedetomidine during surgery. Additionally, 1 µg/kg of dexmedetomidine was infused immediately after cardiopulmonary bypass was initiated. The incidence of acute kidney injury was defined following Kidney Disease Improving Global Outcomes guidelines. RESULTS The final analysis included 139 patients. The incidence of acute kidney injury did not differ between dexmedetomidine and control groups (16.9% vs 23.5%; odds ratio 0.661; 95% CI 0.285 to 1.525; P = .33). Similarly, neither the incidence of abnormal postoperative estimated glomerular filtration rate values (P = .96) nor the incidence of arrhythmia, mechanical ventilation duration, length of stay in the intensive care unit, and hospitalization differed between the two groups. CONCLUSIONS Intraoperative dexmedetomidine did not reduce acute kidney injury incidence in pediatric cardiac surgery patients.
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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
| | - 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
| | - Woong-Han Kim
- Department of Cardiothoracic Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Jae Gun Kwak
- Department of Cardiothoracic Surgery, Seoul National University Hospital, 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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Lonsdale DO, Kipper K, Baker EH, Barker CIS, Oldfield I, Philips BJ, Johnston A, Rhodes A, Sharland M, Standing JF. β-Lactam antimicrobial pharmacokinetics and target attainment in critically ill patients aged 1 day to 90 years: the ABDose study. J Antimicrob Chemother 2020; 75:3625-3634. [DOI: 10.1093/jac/dkaa363] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/09/2020] [Indexed: 01/16/2023] Open
Abstract
Abstract
Background
The pharmacokinetics of β-lactam antibiotics in critical illness remain poorly characterized, particularly in neonates, children and the elderly. We undertook a pharmacokinetic study of commonly used β-lactam antibiotics in critically ill patients of all ages. The aims were to produce a whole-life β-lactam pharmacokinetic model and describe the extent to which standard doses achieve pharmacokinetic/pharmacodynamic targets associated with clinical cure.
Patients and methods
A total of 212 critically ill participants with an age range from 1 day (gestational age 24 weeks) to 90 years were recruited from a UK hospital, providing 1339 pharmacokinetic samples. Population pharmacokinetic analysis was undertaken using non-linear mixed-effects modelling (NONMEM) for each drug. Pooled data were used to estimate maturation and decline of β-lactam pharmacokinetics throughout life.
Results
Pharmacokinetic models for eight drugs were described, including what is thought to be the first benzylpenicillin model in critically ill adults. We estimate that 50% of adult β-lactam clearance is achieved by 43 weeks post-menstrual age (chronological plus gestational age). Fifty percent of decline from peak adult clearance occurs by 71 years. Paediatric participants were significantly less likely than adults to achieve pharmacokinetic/pharmacodynamic targets with standard antibiotic doses (P < 0.01).
Conclusions
We believe this to be the first prospective whole-life antibiotic pharmacokinetic study in the critically ill. The study provides further evidence that standard antibiotic doses fail to achieve pharmacokinetic/pharmacodynamic targets associated with clinical success in adults, children and neonates. Maturation and decline parameters estimated from this study could be adopted as a standard for future prospective studies.
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Affiliation(s)
- Dagan O Lonsdale
- Institute for Infection and Immunity, St George’s, University of London, London, UK
- St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Karin Kipper
- Institute for Infection and Immunity, St George’s, University of London, London, UK
- Institute of Chemistry, University of Tartu, Tartu, Estonia
- Analytical Services International Ltd, London, UK
| | - Emma H Baker
- Institute for Infection and Immunity, St George’s, University of London, London, UK
- St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Charlotte I S Barker
- Institute for Infection and Immunity, St George’s, University of London, London, UK
- St George’s University Hospitals NHS Foundation Trust, London, UK
- UCL Great Ormond Street Institute of Child Health, London, UK
| | - Isobel Oldfield
- Institute for Infection and Immunity, St George’s, University of London, London, UK
| | | | - Atholl Johnston
- Analytical Services International Ltd, London, UK
- Clinical Pharmacology, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Andrew Rhodes
- St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Mike Sharland
- Institute for Infection and Immunity, St George’s, University of London, London, UK
- St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Joseph F Standing
- Institute for Infection and Immunity, St George’s, University of London, London, UK
- UCL Great Ormond Street Institute of Child Health, London, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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Preijers T, Schütte LM, Kruip MJHA, Cnossen MH, Leebeek FWG, van Hest RM, Mathôt RAA. Population Pharmacokinetics of Clotting Factor Concentrates and Desmopressin in Hemophilia. Clin Pharmacokinet 2020; 60:1-16. [PMID: 32936401 PMCID: PMC7808974 DOI: 10.1007/s40262-020-00936-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hemophilia A and B are bleeding disorders caused by a deficiency of clotting factor VIII and IX, respectively. Patients with severe hemophilia (< 0.01 IU mL−1) and some patients with moderate hemophilia (0.01–0.05 IU mL−1) administer clotting factor concentrates prophylactically. Desmopressin (d-amino d-arginine vasopressin) can be applied in patients with non-severe hemophilia A. The aim of administration of factor concentrates or desmopressin is the prevention or cessation of bleeding. Despite weight-based dosing, it has been demonstrated that factor concentrates still exhibit considerable pharmacokinetic variability. Population pharmacokinetic analyses, in which this variability is quantified and explained, are increasingly performed in hemophilia research. These analyses can assist in the identification of important patient characteristics and can be applied to perform patient-tailored dosing. This review aims to present and discuss the population pharmacokinetic analyses that have been conducted to develop population pharmacokinetic models describing factor levels after administration of factor VIII or factor IX concentrates or d-amino d-arginine vasopressin. In total, 33 publications were retrieved from the literature. Two approaches were applied to perform population pharmacokinetic analyses, the standard two-stage approach and non-linear mixed-effect modeling. Using the standard two-stage approach, four population pharmacokinetic models were established describing factor VIII levels. In the remaining 29 analyses, the non-linear mixed-effect modeling approach was applied. NONMEM was the preferred software to establish population pharmacokinetic models. In total, 18 population pharmacokinetic analyses were conducted on the basis of data from a single product. From all available population pharmacokinetic analyses, 27 studies also included data from pediatric patients. In the majority of the population pharmacokinetic models, the population pharmacokinetic parameters were allometrically scaled using actual body weight. In this review, the available methods used for constructing the models, key features of these models, patient population characteristics, and established covariate relationships are described in detail.
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Affiliation(s)
- Tim Preijers
- Hospital Pharmacy-Clinical Pharmacology, Academic University Medical Centers, Location AMC, Amsterdam, The Netherlands
| | - Lisette M Schütte
- Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marieke J H A Kruip
- Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marjon H Cnossen
- Department of Pediatric Hematology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Frank W G Leebeek
- Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Reinier M van Hest
- Hospital Pharmacy-Clinical Pharmacology, Academic University Medical Centers, Location AMC, Amsterdam, The Netherlands
| | - Ron A A Mathôt
- Hospital Pharmacy-Clinical Pharmacology, Academic University Medical Centers, Location AMC, Amsterdam, The Netherlands. .,Hospital Pharmacy-Clinical Pharmacology, Amsterdam University Medical Centers, Location AMC, University of Amsterdam, Meibergdreef 9, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands.
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Langenhorst JB, Dorlo TPC, van Maarseveen EM, Nierkens S, Kuball J, Boelens JJ, van Kesteren C, Huitema ADR. Population Pharmacokinetics of Fludarabine in Children and Adults during Conditioning Prior to Allogeneic Hematopoietic Cell Transplantation. Clin Pharmacokinet 2020; 58:627-637. [PMID: 30327943 PMCID: PMC6451721 DOI: 10.1007/s40262-018-0715-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background Fludarabine is often used as an important drug in reduced toxicity conditioning regimens prior to hematopoietic cell transplantation (HCT). As no definitive pharmacokinetic (PK) basis for HCT dosing for the wide age and weight range in HCT is available, linear body surface area (BSA)-based dosing is still used. Objective We sought to describe the population PK of fludarabine in HCT recipients of all ages. Methods From 258 HCT recipients aged 0.3–74 years, 2605 samples were acquired on days 1 (42%), 2 (17%), 3 (4%) and 4 (37%) of conditioning. Herein, the circulating metabolite of fludarabine was quantified, and derived concentration-time data were used to build a population PK model using non-linear mixed-effects modelling. Results Variability was extensive where area under the curve ranged from 10 to 66 mg h/L. A three-compartment model with first-order kinetics best described the data. Actual body weight (BW) with standard allometric scaling was found to be the best body-size descriptor for all PK parameters. Estimated glomerular filtration rate (eGFR) was included as a descriptor of renal function. Thus, clearance was differentiated into a non-renal (3.24 ± 20% L/h/70 kg) and renal (eGFR × 0.782 ± 11% L/h/70 kg) component. The typical volumes of distribution of the central (V1), peripheral (V2), and second peripheral (V3) compartments were 39 ± 8%, 20 ± 11%, and 50 ± 9% L/70 kg respectively. Intercompartmental clearances between V1 and V2, and V1 and V3, were 8.6 ± 8% and 3.8 ± 13% L/h/70 kg, respectively. Conclusion BW and eGFR are important predictors of fludarabine PK. Therefore, current linear BSA-based dosing leads to highly variable exposure, which may lead to variable treatment outcome.
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Affiliation(s)
- Jurgen B Langenhorst
- Pediatric Blood and Marrow Transplant Program, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Thomas P C Dorlo
- Department of Pharmacy and Pharmacology, Antoni van Leeuwenhoek Hospital/Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Erik M van Maarseveen
- Department of Clinical Pharmacy, University Medical Centre, Utrecht, Utrecht University, Heidelberglaan 100: D.00.X, 3584 CX, Utrecht, The Netherlands
| | - Stefan Nierkens
- Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Jürgen Kuball
- Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Hematology, University Medical Centre, Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Jaap Jan Boelens
- Pediatric Blood and Marrow Transplant Program, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Stem Cell Transplant and Cellular Therapies; Pediatrics, Memorial Sloan Kettering Cancer Centre, New York, NY, USA
| | - Charlotte van Kesteren
- Pediatric Blood and Marrow Transplant Program, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Alwin D R Huitema
- Department of Pharmacy and Pharmacology, Antoni van Leeuwenhoek Hospital/Netherlands Cancer Institute, Amsterdam, The Netherlands. .,Department of Clinical Pharmacy, University Medical Centre, Utrecht, Utrecht University, Heidelberglaan 100: D.00.X, 3584 CX, Utrecht, The Netherlands.
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Germovsek E, Osborne L, Gunaratnam F, Lounis SA, Busquets FB, Standing JF, Sinha AK. Development and external evaluation of a population pharmacokinetic model for continuous and intermittent administration of vancomycin in neonates and infants using prospectively collected data. J Antimicrob Chemother 2020; 74:1003-1011. [PMID: 30668696 DOI: 10.1093/jac/dky525] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/05/2018] [Accepted: 11/16/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Vancomycin is commonly used for nosocomial bacterial pathogens causing late-onset septicaemia in preterm infants. We prospectively collected pharmacokinetic data aiming to describe pharmacokinetics and determine covariates contributing to the variability in neonatal vancomycin pharmacokinetics. Further, we aimed to use the model to compare the ratio of AUC24 at steady-state to the MIC (AUC24,ss/MIC) of several intermittent and continuous dosing regimens. METHODS Newborns receiving vancomycin for suspected or confirmed late-onset sepsis were included. Peak and trough concentrations for intermittent vancomycin dosing and steady-state concentrations for continuous vancomycin dosing were measured. NONMEM 7.3 was used for population pharmacokinetic analysis. Monte Carlo simulations were performed to compare dosing schemes. RESULTS Data from 54 infants were used for model development and from 34 infants for the model evaluation {corrected gestational age [median (range)] = 29 (23.7-41.9) weeks and 28 (23.4-41.7) weeks, respectively}. The final model was a one-compartment model. Weight and postmenstrual age were included a priori, and then no additional covariate significantly improved the model fit. Final model parameter estimates [mean (SEM)]: CL = 5.7 (0.3) L/h/70 kg and V = 39.3 (3.7) L/70 kg. Visual predictive check of the evaluation dataset confirmed the model can predict external data. Simulations using MIC of 1 mg/L showed that for neonates with gestational age ≤25 weeks and postnatal age ≤2 weeks AUC24,ss/MIC was lower with the intermittent regimen (median 482 versus 663). CONCLUSIONS A population pharmacokinetic model for continuous and intermittent vancomycin administration in infants was developed. Continuous administration might be favourable for treating infections caused by resistant microorganisms in very young and immature infants.
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Affiliation(s)
- Eva Germovsek
- Inflammation, Infection and Rheumatology Section, UCL Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, UK.,Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Leanne Osborne
- Neonatal Unit, Royal London Hospital, Barts Health NHS Trust, Whitechapel Road, Whitechapel, London, UK
| | - Flora Gunaratnam
- Centre for Genomics and Child Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, UK
| | - Shehrazed A Lounis
- Centre for Genomics and Child Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, UK
| | - Ferran Bossacoma Busquets
- Inflammation, Infection and Rheumatology Section, UCL Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, UK.,Hospital Sant Joan de Deu, Passeig Hospital Sant Joan de Deu 2, Barcelona, Spain
| | - Joseph F Standing
- Inflammation, Infection and Rheumatology Section, UCL Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, UK
| | - Ajay K Sinha
- Neonatal Unit, Royal London Hospital, Barts Health NHS Trust, Whitechapel Road, Whitechapel, London, UK.,Centre for Genomics and Child Health, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, UK
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Sridharan K, Al Daylami A. Clinical audit of gentamicin use by Bayesian pharmacokinetic approach in critically ill children. J Infect Chemother 2020; 26:540-548. [DOI: 10.1016/j.jiac.2020.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/15/2020] [Accepted: 01/22/2020] [Indexed: 02/09/2023]
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Badée J, Fowler S, de Wildt SN, Collier AC, Schmidt S, Parrott N. The Ontogeny of UDP-glucuronosyltransferase Enzymes, Recommendations for Future Profiling Studies and Application Through Physiologically Based Pharmacokinetic Modelling. Clin Pharmacokinet 2020; 58:189-211. [PMID: 29862468 DOI: 10.1007/s40262-018-0681-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Limited understanding of drug pharmacokinetics in children is one of the major challenges in paediatric drug development. This is most critical in neonates and infants owing to rapid changes in physiological functions, especially in the activity of drug-metabolising enzymes. Paediatric physiologically based pharmacokinetic models that integrate ontogeny functions for cytochrome P450 enzymes have aided our understanding of drug exposure in children, including those under the age of 2 years. Paediatric physiologically based pharmacokinetic models have consequently been recognised by the European Medicines Agency and the US Food and Drug Administration as innovative tools in paediatric drug development and regulatory decision making. However, little is currently known about age-related changes in UDP-glucuronosyltransferase-mediated metabolism, which represents the most important conjugation reaction for xenobiotics. Therefore, the objective of the review was to conduct a thorough literature survey to summarise our current understanding of age-related changes in UDP-glucuronosyltransferases as well as associated clinical and experimental sources of variance. Our findings indicate that there are distinct differences in UDP-glucuronosyltransferase expression and activity between isoforms for different age groups. In addition, there is substantial variability between individuals and laboratories reported for human liver microsomes, which results in part from a lack of standardised experimental conditions. Therefore, we provide a number of best practice recommendations for experimental conditions, which ultimately may help improve the quality of data used for quantitative clinical pharmacology approaches, and thus for safe and effective pharmacotherapy in children.
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Affiliation(s)
- Justine Badée
- Department of Pharmaceutics, Center for Pharmacometrics and Systems Pharmacology, University of Florida at Lake Nona, Orlando, FL, USA
| | - Stephen Fowler
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Centre Basel, Grenzacherstrasse 124, 4070, Basel, Switzerland
| | - Saskia N de Wildt
- Department of Pharmacology and Toxicology, Radboud University, Nijmegen, The Netherlands.,Intensive Care and Department of Paediatric Surgery, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Abby C Collier
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC, Canada
| | - Stephan Schmidt
- Department of Pharmaceutics, Center for Pharmacometrics and Systems Pharmacology, University of Florida at Lake Nona, Orlando, FL, USA
| | - Neil Parrott
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Centre Basel, Grenzacherstrasse 124, 4070, Basel, Switzerland.
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Abstract
Objectives The objectives of this study were to investigate the population pharmacokinetics of posaconazole in immunocompromised children, evaluate the influence of patient characteristics on posaconazole exposure and perform simulations to recommend optimal starting doses. Methods Posaconazole plasma concentrations from paediatric patients undergoing therapeutic drug monitoring were extracted from a tertiary paediatric hospital database. These were merged with covariates collected from electronic sources and case-note reviews. An allometrically scaled population-pharmacokinetic model was developed to investigate the effect of tablet and suspension relative bioavailability, nonlinear bioavailability of suspension, followed by a step-wise covariate model building exercise to identify other important sources of variability. Results A total of 338 posaconazole plasma concentrations samples were taken from 117 children aged 5 months to 18 years. A one-compartment model was used, with tablet apparent clearance standardised to a 70-kg individual of 15 L/h. Suspension was found to have decreasing bioavailability with increasing dose; the estimated suspension dose to yield half the tablet bioavailability was 99 mg/m2. Diarrhoea and proton pump inhibitors were also associated with reduced suspension bioavailability. Conclusions In the largest population-pharmacokinetic study to date in children, we have found similar covariate effects to those seen in adults, but low bioavailability of suspension in patients with diarrhoea or those taking concurrent proton pump inhibitors, which may in particular limit the use of posaconazole in these patients. Electronic supplementary material The online version of this article (10.1007/s40262-018-0658-1) contains supplementary material, which is available to authorized users.
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Germovsek E, Barker CIS, Sharland M, Standing JF. Pharmacokinetic-Pharmacodynamic Modeling in Pediatric Drug Development, and the Importance of Standardized Scaling of Clearance. Clin Pharmacokinet 2020; 58:39-52. [PMID: 29675639 PMCID: PMC6325987 DOI: 10.1007/s40262-018-0659-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Pharmacokinetic/pharmacodynamic (PKPD) modeling is important in the design and conduct of clinical pharmacology research in children. During drug development, PKPD modeling and simulation should underpin rational trial design and facilitate extrapolation to investigate efficacy and safety. The application of PKPD modeling to optimize dosing recommendations and therapeutic drug monitoring is also increasing, and PKPD model-based dose individualization will become a core feature of personalized medicine. Following extensive progress on pediatric PK modeling, a greater emphasis now needs to be placed on PD modeling to understand age-related changes in drug effects. This paper discusses the principles of PKPD modeling in the context of pediatric drug development, summarizing how important PK parameters, such as clearance (CL), are scaled with size and age, and highlights a standardized method for CL scaling in children. One standard scaling method would facilitate comparison of PK parameters across multiple studies, thus increasing the utility of existing PK models and facilitating optimal design of new studies.
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Affiliation(s)
- Eva Germovsek
- Infection, Inflammation and Rheumatology Section, UCL Great Ormond Street Institute of Child Heath, University College London, London, UK. .,Pharmacometrics Research Group, Department of Pharmaceutical Biosciences, Uppsala University, PO Box 591, 751 24, Uppsala, Sweden.
| | - Charlotte I S Barker
- Infection, Inflammation and Rheumatology Section, UCL Great Ormond Street Institute of Child Heath, University College London, London, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK
| | - Mike Sharland
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK
| | - Joseph F Standing
- Infection, Inflammation and Rheumatology Section, UCL Great Ormond Street Institute of Child Heath, University College London, London, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK
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Marques MR, Garcia‐Robles A, Usach I, Vento M, Poveda JL, Peris JE, Mangas‐Sanjuan V. Topiramate pharmacokinetics in neonates undergoing therapeutic hypothermia and proposal of an optimised dosing schedule. Acta Paediatr 2020; 109:300-308. [PMID: 31336401 DOI: 10.1111/apa.14944] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/09/2019] [Accepted: 07/18/2019] [Indexed: 11/28/2022]
Abstract
AIM The adequate dosing of topiramate in neonates undergoing therapeutic hypothermia has not been established. The aim of this study was to design a dosing schedule capable of providing topiramate serum concentrations within the accepted therapeutic range. METHODS Neonates (n = 52) with hypoxic ischaemic encephalopathy and subjected to therapeutic hypothermia were dosed with topiramate, 5 mg/kg on day one and 3 mg/kg on days two to five, to decrease seizure events. A total of 451 topiramate serum concentrations obtained in the patients were used to develop a population pharmacokinetic model using a non-linear mixed-effects modelling approach. RESULTS A one-compartment model with first-order absorption and two different clearance terms, one for the cooling period and another for the post-warming period, were used to describe the concentration-time topiramate data. The probability of no-seizure events could not be related to topiramate concentrations, which was attributed to excessively low topiramate concentrations. A modified dosage schedule was designed with the aim of obtaining more than 90% of patients with topiramate concentrations within the therapeutic range after the first dose. CONCLUSION The dosage schedule of topiramate in these patients should be modified with the aim of decreasing the frequency of seizure events.
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Affiliation(s)
- María Remedios Marques
- Department of Pharmacy Services University and Polytechnic Hospital La Fe Valencia Spain
| | - Ana Garcia‐Robles
- Division of Neonatology University and Polytechnic Hospital La Fe Valencia Spain
| | - Iris Usach
- Department of Pharmacy and Pharmaceutical Technology and Parasitology University of Valencia Valencia Spain
| | - Maximo Vento
- Division of Neonatology University and Polytechnic Hospital La Fe Valencia Spain
| | - José Luis Poveda
- Department of Pharmacy Services University and Polytechnic Hospital La Fe Valencia Spain
| | - José Esteban Peris
- Department of Pharmacy and Pharmaceutical Technology and Parasitology University of Valencia Valencia Spain
| | - Victor Mangas‐Sanjuan
- Department of Pharmacy and Pharmaceutical Technology and Parasitology University of Valencia Valencia Spain
- Interuniversity Research Institute for Molecular Recognition and Technological Development Polytechnic University of Valencia‐University of Valencia Valencia Spain
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Hallik M, Ilmoja M, Standing JF, Soeorg H, Jalas T, Raidmäe M, Uibo K, Köbas K, Sõnajalg M, Takkis K, Veigure R, Kipper K, Starkopf J, Metsvaht T. Population pharmacokinetics and pharmacodynamics of dobutamine in neonates on the first days of life. Br J Clin Pharmacol 2020; 86:318-328. [PMID: 31657867 PMCID: PMC7015735 DOI: 10.1111/bcp.14146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/05/2019] [Accepted: 09/26/2019] [Indexed: 11/29/2022] Open
Abstract
AIMS To describe the pharmacokinetics (PK) and concentration-related effects of dobutamine in critically ill neonates in the first days of life, using nonlinear mixed effects modelling. METHODS Dosing, plasma concentration and haemodynamic monitoring data from a dose-escalation study were analysed with a simultaneous population PK and pharmacodynamic model. Neonates receiving continuous infusion of dobutamine 5-20 μg kg-1 min-1 were included. Left ventricular ejection fraction (LVEF) and cardiac output of right and left ventricle (RVO, LVO) were measured on echocardiography; heart rate (HR), mean arterial pressure (MAP), peripheral arterial oxygen saturation and cerebral regional oxygen saturation were recorded from patient monitors. RESULTS Twenty-eight neonates with median (range) gestational age of 30.4 (22.7-41.0) weeks and birth weight (BW) of 1618 (465-4380) g were included. PK data were adequately described by 1-compartmental linear structural model. Dobutamine clearance (CL) was described by allometric scaling on BW with sigmoidal maturation function of postmenstrual age (PMA). The final population PK model parameter mean typical value (standard error) estimates, standardised to median BW of 1618 g, were 41.2 (44.5) L h-1 for CL and 5.29 (0.821) L for volume of distribution, which shared a common between subject variability of 29% (17.2%). The relationship between dobutamine concentration and RVO/LVEF was described by linear model, between concentration and LVO/HR/MAP/cerebral fractional tissue oxygen extraction by sigmoidal Emax model. CONCLUSION In the postnatal transitional period, PK of dobutamine was described by a 1-compartmental linear model, CL related to BW and PMA. A concentration-response relationship with haemodynamic variables has been established.
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Affiliation(s)
- Maarja Hallik
- Department of Anaesthesiology and Intensive Care, Institute of Clinical MedicineUniversity of TartuTartuEstonia
| | | | - Joseph F. Standing
- Inflammation, Infection and Rheumatology section, Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
| | - Hiie Soeorg
- Department of Microbiology, Institute of Biomedicine and Translational MedicineUniversity of TartuTartuEstonia
| | - Tiiu Jalas
- Clinic of PaediatricsTallinn Children's HospitalTallinnEstonia
| | - Maila Raidmäe
- Clinic of PaediatricsTallinn Children's HospitalTallinnEstonia
| | - Karin Uibo
- Clinic of PaediatricsTallinn Children's HospitalTallinnEstonia
| | - Kristel Köbas
- Clinic of PaediatricsTartu University HospitalTartuEstonia
| | | | - Kalev Takkis
- Analytical Services InternationalSt George's University of LondonCranmer TerraceLondonUK
| | - Rūta Veigure
- Institute of ChemistryUniversity of TartuTartuEstonia
| | - Karin Kipper
- Analytical Services InternationalSt George's University of LondonCranmer TerraceLondonUK
- Institute of ChemistryUniversity of TartuTartuEstonia
| | - Joel Starkopf
- Department of Anaesthesiology and Intensive Care, Institute of Clinical MedicineUniversity of TartuTartuEstonia
- Clinic of Anaesthesiology and Intensive CareTartu University HospitalTartuEstonia
| | - Tuuli Metsvaht
- Clinic of Anaesthesiology and Intensive CareTartu University HospitalTartuEstonia
- Department of Paediatrics, Institute of Clinical MedicineUniversity of TartuTartuEstonia
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Adiwidjaja J, Boddy AV, McLachlan AJ. Implementation of a Physiologically Based Pharmacokinetic Modeling Approach to Guide Optimal Dosing Regimens for Imatinib and Potential Drug Interactions in Paediatrics. Front Pharmacol 2020; 10:1672. [PMID: 32082165 PMCID: PMC7002565 DOI: 10.3389/fphar.2019.01672] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/23/2019] [Indexed: 12/18/2022] Open
Abstract
Long-term use of imatinib is effective and well-tolerated in children with chronic myeloid leukaemia (CML) yet defining an optimal dosing regimen for imatinib in younger patients is a challenge. The potential interactions between imatinib and coadministered drugs in this "special" population also remains largely unexplored. This study implements a physiologically based pharmacokinetic (PBPK) modeling approach to investigate optimal dosing regimens and potential drug interactions with imatinib in the paediatric population. A PBPK model for imatinib was developed in the Simcyp Simulator (version 17) utilizing in silico, in vitro drug metabolism, and in vivo pharmacokinetic data and verified using an independent set of published clinical pharmacokinetic data. The model was then extrapolated to children and adolescents (aged 2-18 years) by incorporating developmental changes in organ size and maturation of drug-metabolising enzymes and plasma protein responsible for imatinib disposition. The PBPK model described imatinib pharmacokinetics in adult and paediatric populations and predicted drug interaction with carbamazepine, a cytochrome P450 (CYP)3A4 and 2C8 inducer, with a good accuracy (evaluated by visual inspections of the simulation results and predicted pharmacokinetic parameters that were within 1.25-fold of the clinically observed values). The PBPK simulation suggests that the optimal dosing regimen range for imatinib is 230-340 mg/m2/d in paediatrics, which is supported by the recommended initial dose for treatment of childhood CML. The simulations also highlighted that children and adults being treated with imatinib have similar vulnerability to CYP modulations. A PBPK model for imatinib was successfully developed with an excellent performance in predicting imatinib pharmacokinetics across age groups. This PBPK model is beneficial to guide optimal dosing regimens for imatinib and predict drug interactions with CYP modulators in the paediatric population.
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Affiliation(s)
- Jeffry Adiwidjaja
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW, Australia
| | - Alan V. Boddy
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
- University of South Australia Cancer Research Institute, University of South Australia, Adelaide, SA, Australia
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Chiesa R, Standing JF, Winter R, Nademi Z, Chu J, Pinner D, Kloprogge F, McLellen S, Amrolia PJ, Rao K, Lucchini G, Silva J, Ciocarlie O, Lazareva A, Gennery AR, Doncheva B, Cant AJ, Hambleton S, Flood T, Rogerson E, Devine K, Prunty H, Heales S, Veys P, Slatter M. Proposed Therapeutic Range of Treosulfan in Reduced Toxicity Pediatric Allogeneic Hematopoietic Stem Cell Transplant Conditioning: Results From a Prospective Trial. Clin Pharmacol Ther 2019; 108:264-273. [PMID: 31701524 PMCID: PMC7484914 DOI: 10.1002/cpt.1715] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/28/2019] [Indexed: 12/18/2022]
Abstract
Treosulfan is given off‐label in pediatric allogeneic hematopoietic stem cell transplant. This study investigated treosulfan's pharmacokinetics (PKs), efficacy, and safety in a prospective trial. Pediatric patients (n = 87) receiving treosulfan‐fludarabine conditioning were followed for at least 1 year posttransplant. PKs were described with a two‐compartment model. During follow‐up, 11 of 87 patients died and 12 of 87 patients had low engraftment (≤ 20% myeloid chimerism). For each increase in treosulfan area under the curve from zero to infinity (AUC(0‐∞)) of 1,000 mg hour/L the hazard ratio (95% confidence interval) for mortality increase was 1.46 (1.23–1.74), and the hazard ratio for low engraftment was 0.61 (0.36–1.04). A cumulative AUC(0‐∞) of 4,800 mg hour/L maximized the probability of success (> 20% engraftment and no mortality) at 82%. Probability of success with AUC(0‐∞) between 80% and 125% of this target were 78% and 79%. Measuring PK at the first dose and individualizing the third dose may be required in nonmalignant disease.
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Affiliation(s)
- Robert Chiesa
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Joseph F Standing
- Pharmacy Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,Infection, Immunity, and Inflammation, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Robert Winter
- Chemical Pathology Department, Great Ormond Street Hospital for Children,, NHS Foundation Trust, London, UK
| | - Zohreh Nademi
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Jan Chu
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Danielle Pinner
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Frank Kloprogge
- Institute for Global Health, University College London, London, UK
| | - Susan McLellen
- Clinical Biochemistry, Integrated Laboratory Medicine Directorate, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Persis J Amrolia
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,Infection, Immunity, and Inflammation, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Kanchan Rao
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Giovanna Lucchini
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Juliana Silva
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Oana Ciocarlie
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Arina Lazareva
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Andrew R Gennery
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Bilyana Doncheva
- Pharmacy Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Andrew J Cant
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Sophie Hambleton
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Terence Flood
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Elizabeth Rogerson
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Kirsty Devine
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Helen Prunty
- Chemical Pathology Department, Great Ormond Street Hospital for Children,, NHS Foundation Trust, London, UK
| | - Simon Heales
- Chemical Pathology Department, Great Ormond Street Hospital for Children,, NHS Foundation Trust, London, UK
| | - Paul Veys
- Bone Marrow Transplantation Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,Infection, Immunity, and Inflammation, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Mary Slatter
- Bone Marrow Transplantation Department, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
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Gastine S, Rashed AN, Hsia Y, Jackson C, Barker CIS, Mathur S, Tomlin S, Lutsar I, Bielicki J, Standing JF, Sharland M. GAPPS (Grading and Assessment of Pharmacokinetic-Pharmacodynamic Studies) a critical appraisal system for antimicrobial PKPD studies - development and application in pediatric antibiotic studies. Expert Rev Clin Pharmacol 2019; 12:1091-1098. [PMID: 31747323 DOI: 10.1080/17512433.2019.1695600] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: There are limited data on optimal dosing of antibiotics in different age groups for neonates and children. Clinicians usually consult pediatric formularies or online databases for dose selection, but these have variable recommendations, are usually based on expert opinion and are not graded based on the existing pharmacokinetic-pharmacodynamic (PKPD) studies. We describe here a potential new tool that could be used to grade the strength of evidence emanating from PKPD studies.Areas covered: A scoring system was developed (GAPPS tool) to quantify the strength of each PK assessment and rate the studies quality in already published articles. GAPPS was evaluated by applying it to pediatric PKPD studies of antibiotics from the 2019 Essential Medicines List for children (EMLC), identified through a search of PubMed.Expert opinion: Evidence for most antibiotic dose selection decisions was generally weak, coming from individual PK studies and lacked PKPD modeling and simulations. However, the quality of evidence appears to have improved over the last two decades.Incorporating a formal grading system, such as GAPPS, into formulary development will provide a transparent tool to support decision-making in clinical practice and guideline development, and guide PKPD authors on study designs most likely to influence guidelines.
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Affiliation(s)
- Silke Gastine
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Asia N Rashed
- Pharmacy Department, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK.,Institute of Pharmaceutical Science, King's College London, London, UK
| | - Yingfen Hsia
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK.,School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Charlotte Jackson
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Charlotte I S Barker
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Shrey Mathur
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Stephen Tomlin
- Pharmacy Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Irja Lutsar
- Department of Microbiology, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Julia Bielicki
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK.,Paediatric Pharmacology Group, University of Basel Children's Hospital, Basel, Switzerland
| | - Joseph F Standing
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK.,Pharmacy Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Mike Sharland
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, UK
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Kos MK, Miksić M, Jovanović M, Roškar R, Grosek Š, Grabnar I. Maturation of midazolam clearance in critically ill children with severe bronchiolitis: A population pharmacokinetic analysis. Eur J Pharm Sci 2019; 141:105095. [PMID: 31626965 DOI: 10.1016/j.ejps.2019.105095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/24/2019] [Accepted: 09/29/2019] [Indexed: 11/28/2022]
Abstract
PURPOSE The aim of the present study was to develop a population pharmacokinetic model of midazolam, and to evaluate the influence of maturation process and other variability factors in critically ill children with severe acute bronchiolitis, who received a long-term intravenous infusion of midazolam. METHODS In the study were included 49 critically ill children of both genders (from 0 to 130 weeks of age) with severe acute bronchiolitis hospitalised in intensive care units. Nonlinear mixed effects modelling approach was applied for data analyses and simulations. RESULTS The final model is a two-compartment model that includes the effects of body weight using allometric scaling with fixed exponents and maturation of clearance. For a typical subject, scaled to the adult body weight of 70 kg, population pharmacokinetic values were estimated at 8.52 L/h for clearance (when maturation function was 1), 25.5 L/h for intercompartmental clearance, and 5.71 L and 39.8 L for the volume of the central and peripheral compartment, respectively. Based on the final model, maturation reaches 50% of the adult clearance in 45.9 weeks of postmenstrual age. The influence of gender, ABCB1 genotype and biochemical parameters on midazolam clearance was not detected. Results of simulations indicate the need for reduced dosing in certain groups of patients in order to maintain plasma concentrations of midazolam within recommended values. CONCLUSIONS The developed population pharmacokinetic model can contribute to the dosing optimisation of midazolam, especially in critically ill children as it includes the influence of size and maturation of clearance, which are important parameters for achieving the desired plasma concentrations of midazolam.
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Affiliation(s)
- Mojca Kerec Kos
- Faculty of Pharmacy, University of Ljubljana, Askerceva cesta 7, Ljubljana 1000, Slovenia.
| | - Mirjana Miksić
- Division of Paediatrics, University Medical Centre Maribor, Ljubljanska ulica 5, Maribor 2000, Slovenia; Division of Gynaecology and Perinatology, Department of Perinatology, University Medical Centre Maribor, Ljubljanska ulica 5, Maribor 2000, Slovenia
| | - Marija Jovanović
- Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, Belgrade 11221, Serbia
| | - Robert Roškar
- Faculty of Pharmacy, University of Ljubljana, Askerceva cesta 7, Ljubljana 1000, Slovenia
| | - Štefan Grosek
- Division of Surgery, Department of Paediatric Surgery and Intensive Therapy, University Medical Centre Ljubljana, Bohoriceva ulica 20, Ljubljana 1525, Slovenia; Department of Perinatology, Divison of Gynecology and Obstetrics, University Medical Centre Ljubljana, Šlajmerjeva 3, Ljubljana 1000, Slovenia; Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana 1000, Slovenia
| | - Iztok Grabnar
- Faculty of Pharmacy, University of Ljubljana, Askerceva cesta 7, Ljubljana 1000, Slovenia
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Germovsek E, Lutsar I, Kipper K, Karlsson MO, Planche T, Chazallon C, Meyer L, Trafojer UMT, Metsvaht T, Fournier I, Sharland M, Heath P, Standing JF. Plasma and CSF pharmacokinetics of meropenem in neonates and young infants: results from the NeoMero studies. J Antimicrob Chemother 2019; 73:1908-1916. [PMID: 29684147 PMCID: PMC6005047 DOI: 10.1093/jac/dky128] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/12/2018] [Indexed: 01/18/2023] Open
Abstract
Background Sepsis and bacterial meningitis are major causes of mortality and morbidity in neonates and infants. Meropenem, a broad-spectrum antibiotic, is not licensed for use in neonates and infants below 3 months of age and sufficient information on its plasma and CSF disposition and dosing in neonates and infants is lacking. Objectives To determine plasma and CSF pharmacokinetics of meropenem in neonates and young infants and the link between pharmacokinetics and clinical outcomes in babies with late-onset sepsis (LOS). Methods Data were collected in two recently conducted studies, i.e. NeoMero-1 (neonatal LOS) and NeoMero-2 (neonatal meningitis). Optimally timed plasma samples (n = 401) from 167 patients and opportunistic CSF samples (n = 78) from 56 patients were analysed. Results A one-compartment model with allometric scaling and fixed maturation gave adequate fit to both plasma and CSF data; the CL and volume (standardized to 70 kg) were 16.7 (95% CI 14.7, 18.9) L/h and 38.6 (95% CI 34.9, 43.4) L, respectively. CSF penetration was low (8%), but rose with increasing CSF protein, with 40% penetration predicted at a protein concentration of 6 g/L. Increased infusion time improved plasma target attainment, but lowered CSF concentrations. For 24 patients with culture-proven Gram-negative LOS, pharmacodynamic target attainment was similar regardless of the test-of-cure visit outcome. Conclusions Simulations showed that longer infusions increase plasma PTA but decrease CSF PTA. CSF penetration is worsened with long infusions so increasing dose frequency to achieve therapeutic targets should be considered.
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Affiliation(s)
- Eva Germovsek
- Department of Infection, Inflammation and Rheumatology, Great Ormond Street Institute of Child Health, University College London, London, UK.,Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Irja Lutsar
- Department of Microbiology, University of Tartu, Tartu, Estonia
| | - Karin Kipper
- Department of Microbiology, University of Tartu, Tartu, Estonia.,Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, UK
| | - Mats O Karlsson
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Tim Planche
- Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, UK
| | | | | | - Ursula M T Trafojer
- Neonatal Intensive Care Unit, Department for Women and Child Health, University of Padua, Padua, Italy
| | | | | | - Mike Sharland
- Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, UK
| | - Paul Heath
- Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, UK
| | - Joseph F Standing
- Department of Infection, Inflammation and Rheumatology, Great Ormond Street Institute of Child Health, University College London, London, UK.,Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, UK
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A Population Pharmacokinetic Model of Intravenous Dexmedetomidine for Mechanically Ventilated Children after Neurosurgery. J Clin Med 2019; 8:jcm8101563. [PMID: 31581476 PMCID: PMC6832515 DOI: 10.3390/jcm8101563] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/13/2019] [Accepted: 09/24/2019] [Indexed: 01/24/2023] Open
Abstract
Dexmedetomidine is a selective alpha-2 adrenergic agonist with concurrent sedative and analgesic effects, and it is being increasingly used in pediatric anesthesia and intensive care. This study aimed to investigate the pharmacokinetics of intravenous dexmedetomidine in mechanically ventilated children in the intensive care unit (ICU) after neurosurgery. Pediatric patients aged 2–12 years, who were mechanically ventilated in ICU after neurosurgery, were allocated into a low-dose (n = 15) or high-dose (n = 14) group. The low-dose group received dexmedetomidine at a loading dose of 0.25 µg/kg for 10 min, followed by a maintenance dose of 0.25 µg/kg/h for 50 min, whereas the high-dose group received dexmedetomidine at a loading dose of 0.5 µg/kg for 10 min, followed by a maintenance dose of 0.5 µg/kg/h for 50 min. Serial blood samples were collected for a pharmacokinetic analysis up to 480 min after the end of the infusion. The sedative effect of dexmedetomidine was assessed using the Bispectral Index and University of Michigan Sedation Scale. Adverse reactions, electrocardiography findings, and vital signs were monitored for a safety assessment. A population pharmacokinetic analysis was performed using non-linear mixed effects modeling. Dexmedetomidine induced a moderate-to-deep degree of sedation during infusion in both groups. The pharmacokinetics of dexmedetomidine were best described by a two-compartment disposition model with first-order elimination kinetics. The parameters were standardized for a body weight of 70 kg using an allometric power model. The population estimates (95% confidence interval) per 70 kg body weight were as follows: clearance of 81.0 (72.9–90.9) L/h, central volume of distribution of 64.2 (50.6–81.0) L, intercompartment clearance of 116.4 (90.6–156.0) L/h, and peripheral volume of distribution of 167 (132–217) L. No serious adverse reactions or hemodynamic changes requiring the discontinuation of dexmedetomidine were observed. Dexmedetomidine had increased clearance and volume of distribution in mechanically ventilated children in ICU after neurosurgery, thereby indicating the need to adjust the dosage to obtain a target plasma concentration.
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73
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Hayden JC, Bardol M, Doherty DR, Dawkins I, Healy M, Breatnach CV, Gallagher PJ, Cousins G, Standing JF. Optimizing clonidine dosage for sedation in mechanically ventilated children: A pharmacokinetic simulation study. Paediatr Anaesth 2019; 29:1002-1010. [PMID: 31373752 DOI: 10.1111/pan.13715] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/28/2019] [Accepted: 07/29/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND Clonidine is in widespread off-label use as a sedative in mechanically ventilated children, despite limited evidence of efficacy. A variety of dosage regimens have been utilized in clinical practice and in research studies. Within these studies, clonidine has inconsistently shown useful sedation properties. One of the reasons attributed to the inconsistent signs of efficacy is suboptimal clonidine dosing. AIMS This study aims to propose a target plasma concentration and simulate clonidine pharmacokinetics (PK) in a cohort of mechanically ventilated children to evaluate the adequacy of clonidine dosage regimens used in clinical practice and research studies. METHODS A literature search was undertaken to identify a clonidine pharmaockinetic-pharmacodynamics (PKPD) model, from which a target concentration for sedation was defined. Using a previously published PK model, the projected plasma concentrations of 692 mechanically ventilated children (demographics taken from a recent study) were generated. Doses from recently published clinical studies were investigated. Adequacy of each regimen to attain therapeutic clonidine plasma concentrations was assessed. RESULTS A target plasma concentration of above 2 µg/L was proposed. Nine dosage regimens (four intravenous boluses, four intravenous infusions, and one nasogastric route boluses) were evaluated ranging from 1 µg/kg eight hourly intravenous boluses to a regimen up to 3 µg/kg/hr continuous intravenous infusion. Regimens with a loading dose of 2 µg/kg followed by variable continuous infusion of up to 2 µg/kg/hr titrated according to sedation score appear most suitable. Doses should be halved in neonates. CONCLUSION The variety of dosage regimens in the previous studies of clonidine along with difficulties in the conduct of interventional studies may have contributed to the lack of efficacy data to support its use. Simulations of clonidine plasma concentrations based on known population pharmacokinetic parameters suggest a loading dose followed by higher than current practice maintenance dose infusion is required to achieve adequate steady-state concentrations early in treatment. Further PKPD studies will aid in the determination of the optimal clonidine dosage regimen.
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Affiliation(s)
- John C Hayden
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Maddlie Bardol
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Dermot R Doherty
- Paediatric Intensive Care Unit, Our Lady's Children's Hospital, Dublin, Ireland.,Intensive Care Unit, Children's University Hospital, Dublin, Ireland
| | - Ian Dawkins
- Paediatric Intensive Care Unit, Our Lady's Children's Hospital, Dublin, Ireland.,Intensive Care Unit, Children's University Hospital, Dublin, Ireland
| | - Martina Healy
- Paediatric Intensive Care Unit, Our Lady's Children's Hospital, Dublin, Ireland
| | - Cormac V Breatnach
- Paediatric Intensive Care Unit, Our Lady's Children's Hospital, Dublin, Ireland
| | - Paul J Gallagher
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gráinne Cousins
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Joseph F Standing
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
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Schulz J, Kluwe F, Mikus G, Michelet R, Kloft C. Novel insights into the complex pharmacokinetics of voriconazole: a review of its metabolism. Drug Metab Rev 2019; 51:247-265. [PMID: 31215810 DOI: 10.1080/03602532.2019.1632888] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Voriconazole, a second-generation triazole frequently used for the prophylaxis and treatment of invasive fungal infections, undergoes complex metabolism mainly involving various (polymorphic) cytochrome P450 enzymes in humans. Although high inter- and intraindividual variability in voriconazole pharmacokinetics have been observed and the therapeutic range for this compound is relatively narrow, the metabolism of voriconazole has not been fully elucidated yet. The available literature data investigating the multiple different pathways and metabolites are extremely unbalanced and thus the absolute or relative contribution of the different pathways and enzymes involved in the metabolism of voriconazole remains uncertain. Furthermore, other factors such as nonlinear pharmacokinetics caused by auto-inhibition or -induction and polymorphisms of the metabolizing enzymes hinder safe and effective voriconazole dosing in clinical practice and have not yet been studied sufficiently. This review aimed at amalgamating the available literature on the pharmacokinetics of voriconazole in vitro and in vivo, with a special focus on metabolism in adults and children, in order to congregate an overall landscape of the current body of knowledge and identify knowledge gaps, opening the way towards further research in order to foster the understanding, towards better therapeutic dosing decisions.
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Affiliation(s)
- Josefine Schulz
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin , Berlin , Germany
| | - Franziska Kluwe
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin , Berlin , Germany.,Graduate Research Training Program PharMetrX , Berlin/Potsdam , Germany
| | - Gerd Mikus
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg , Heidelberg , Germany
| | - Robin Michelet
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin , Berlin , Germany
| | - Charlotte Kloft
- Department of Clinical Pharmacy and Biochemistry, Institute of Pharmacy, Freie Universitaet Berlin , Berlin , Germany
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75
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Population Pharmacokinetics and Dosing of Milrinone After Patent Ductus Arteriosus Ligation in Preterm Infants. Pediatr Crit Care Med 2019; 20:621-629. [PMID: 30664589 DOI: 10.1097/pcc.0000000000001879] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The postoperative course of patent ductus arteriosus ligation is often complicated by postligation cardiac syndrome, occurring in 10-45% of operated infants. Milrinone might prevent profound hemodynamic instability and improve the recovery of cardiac function in this setting. The present study aimed to describe the population pharmacokinetics of milrinone in premature neonates at risk of postligation cardiac syndrome and give dosing recommendations. DESIGN A prospective single group open-label pharmacokinetics study. SETTINGS Two tertiary care neonatal ICUs: Tallinn Children's Hospital and Tartu University Hospital, Estonia. PATIENTS Ten neonates with postmenstrual age of 24.6-30.1 weeks and postnatal age of 5-27 days undergoing patent ductus arteriosus ligation and at risk of postligation cardiac syndrome, based on echocardiographic assessment of left ventricular output of less than 200 mL/kg/min 1 hour after the surgery. INTERVENTIONS Milrinone at a dose of 0.73 μg/kg/min for 3 hours followed by 0.16 μg/kg/min for 21 hours. Four blood samples from each patient for milrinone plasma concentration measurements were collected. MEASUREMENTS AND MAIN RESULTS Concentration-time data of milrinone were analyzed with nonlinear mixed-effects modeling software (NONMEM Version 7.3 [ICON Development Solutions, Ellicott City, MD]). Probability of target attainment simulations gave a dosing schedule that maximally attains concentration targets of 150-250 μg/L. Milrinone pharmacokinetics was described by a one-compartmental linear model with allometric scaling to bodyweight and an age maturation function of glomerular filtration rate. Parameter estimates for a patient with the median weight were 0.350 (L/hr) for clearance and 0.329 (L) for volume of distribution. The best probability of target attainment was achieved with a loading dose of 0.50 μg/kg/min for 3 hours followed by 0.15 μg/kg/min (postmenstrual age < 27 wk) or 0.20 μg/kg/min (postmenstrual age ≥ 27 wk). CONCLUSIONS Population pharmacokinetic modeling and simulations suggest a slow loading dose followed by maintenance infusion to reach therapeutic milrinone plasma concentrations within the timeframe of the postligation cardiac syndrome.
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76
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Revising Pediatric Vancomycin Dosing Accounting for Nephrotoxicity in a Pharmacokinetic-Pharmacodynamic Model. Antimicrob Agents Chemother 2019; 63:AAC.00067-19. [PMID: 30833429 DOI: 10.1128/aac.00067-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/20/2019] [Indexed: 12/14/2022] Open
Abstract
This study aimed to suggest an initial pediatric vancomycin dose regimen through population pharmacokinetic-pharmacodynamic modeling. A population pharmacokinetic approach was used to analyze vancomycin concentration-time data from a large pediatric cohort. Pharmacokinetic target attainment for patients with bloodstream isolates was compared with clinical outcome using logistic regression and classification and regression trees. Change in serum creatinine during treatment was used as an indicator of acute nephrotoxicity. Probability of acute kidney injury (50% increase from baseline) or kidney failure (75% increase from baseline) was evaluated using logistic regression. An initial dosing regimen was derived, personalized by age, weight, and serum creatinine, using stochastic simulations. Data from 785 hospitalized pediatric patients (1 day to 21 years of age) with suspected Gram-positive infections were collected. Estimated (relative standard error) typical clearance, volume of distribution 1, intercompartmental clearance, and volume of distribution 2 were (standardized to 70 kg) 4.84 (2.38) liters/h, 39.9 (8.15) liters, 3.85 (17.3) liters/h, and 37.8 (10.2) liters, respectively. While cumulative vancomycin exposure correlated positively with the development of nephrotoxicity (713 patients), no clear relationship between vancomycin area under the plasma concentration-time curve and efficacy was found (102 patients). Predicted probability of acute kidney injury and kidney failure with the optimized dosing regimen at day 5 was 10 to 15% and 5 to 10%, increasing by approximately 50% on day 7 and roughly 100% on day 10 across all age groups. This study presents the first data-driven pediatric dose selection to date accounting for nephrotoxicity, and it indicates that cumulative vancomycin exposure best describes risk of acute kidney injury and acute kidney failure.
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77
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Zhuang L, Chen J, Yu J, Marathe A, Sahajwalla C, Borigini M, Maynard J, Burckart GJ, Wang Y. Dosage Considerations for Canakinumab in Children With Periodic Fever Syndromes. Clin Pharmacol Ther 2019; 106:557-567. [DOI: 10.1002/cpt.1302] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 11/02/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Luning Zhuang
- Division of Pharmacometrics Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Jianmeng Chen
- Division of Clinical Pharmacology II Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Jingyu Yu
- Division of Pharmacometrics Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Anshu Marathe
- Division of Clinical Pharmacology II Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Chandra Sahajwalla
- Division of Clinical Pharmacology II Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Mark Borigini
- Division of Pulmonary, Allergy, and Rheumatology Products Office of Drug Evaluation II, Office of New Drugs Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Janet Maynard
- Division of Pulmonary, Allergy, and Rheumatology Products Office of Drug Evaluation II, Office of New Drugs Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Gilbert J. Burckart
- Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
| | - Yaning Wang
- Division of Pharmacometrics Office of Clinical Pharmacology Office of Translational Sciences Center for Drug Evaluation and Research US Food and Drug Administration Silver Spring Maryland USA
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78
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Vancomycin Pharmacokinetics Throughout Life: Results from a Pooled Population Analysis and Evaluation of Current Dosing Recommendations. Clin Pharmacokinet 2019; 58:767-780. [DOI: 10.1007/s40262-018-0727-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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79
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Abstract
BACKGROUND The emergence of coagulase-negative staphylococci with reduced vancomycin susceptibility in some neonatal intensive care units has resulted in an increase of linezolid use. Linezolid pharmacokinetics (PK) and safety in premature infants still need to be better established. METHODS This was a retrospective PK study. All infants who received intravenous linezolid and had linezolid plasma concentrations per standard of care were included. Linezolid concentrations were measured by high performance liquid chromatography. A population PK model was developed using nonlinear mixed effects modeling. Optimal dosing was determined based on achievement of the surrogate pharmacodynamics target for efficacy: a ratio of the area under the concentration-time curve to minimum inhibitory concentration >80. We assessed the occurrence of thrombocytopenia and lactic acidosis in relation with drug exposure. RESULTS A total of 78 plasma concentrations were collected from 26 infants, with a median postnatal age (PNA) of 24 days (8-88) and weight of 1423 g (810-3256). A 1-compartment model described linezolid data well. The final model included PNA and weight on clearance and weight on volume of distribution. Considering an MIC90 of 1 mg/L, all infants reached an area under the concentration-time curve/minimum inhibitory concentration > 80. Although thrombocytopenia and hyperlactatemia occurred frequently, they were not sustained and were not considered related to linezolid. CONCLUSION and was well tolerated in critically ill premature infants. PNA was the main determinant of clearance.
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80
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Standing JF, Ongas MO, Ogwang C, Kagwanja N, Murunga S, Mwaringa S, Ali R, Mturi N, Timbwa M, Manyasi C, Mwalekwa L, Bandika VL, Ogutu B, Waichungo J, Kipper K, Berkley JA. Dosing of Ceftriaxone and Metronidazole for Children With Severe Acute Malnutrition. Clin Pharmacol Ther 2018; 104:1165-1174. [PMID: 29574688 PMCID: PMC6282491 DOI: 10.1002/cpt.1078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 03/15/2018] [Accepted: 03/18/2018] [Indexed: 12/12/2022]
Abstract
Infants and young children with severe acute malnutrition (SAM) are treated with empiric broad-spectrum antimicrobials. Parenteral ceftriaxone is currently a second-line agent for invasive infection. Oral metronidazole principally targets small intestinal bacterial overgrowth. Children with SAM may have altered drug absorption, distribution, metabolism, and elimination. Population pharmacokinetics of ceftriaxone and metronidazole were studied, with the aim of recommending optimal dosing. Eighty-one patients with SAM (aged 2-45 months) provided 234 postdose pharmacokinetic samples for total ceftriaxone, metronidazole, and hydroxymetronidazole. Ceftriaxone protein binding was also measured in 190 of these samples. A three-compartment model adequately described free ceftriaxone, with a Michaelis-Menten model for concentration and albumin-dependent protein binding. A one-compartment model was used for both metronidazole and hydroxymetronidazole, with only 1% of hydroxymetronidazole predicted to be formed during first-pass. Simulations showed 80 mg/kg once daily of ceftriaxone and 12.5 mg/kg twice daily of metronidazole were sufficient to reach therapeutic targets.
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Affiliation(s)
- Joseph F. Standing
- Great Ormond Street Institute of Child HealthUniversity College LondonLondonUK
- Paediatric Infectious Diseases Research GroupInstitute for Infection and Immunity, St. George's, University of LondonLondonUK
| | - Martin O. Ongas
- Center for Research in Therapeutic SciencesStrathmore UniversityNairobiKenya
- KEMRI‐Centre for Clinical ResearchNairobiKenya
| | | | | | | | | | - Rehema Ali
- KEMRI‐Wellcome Trust Research ProgrammeKilifiKenya
| | - Neema Mturi
- KEMRI‐Wellcome Trust Research ProgrammeKilifiKenya
| | - Moline Timbwa
- KEMRI‐Wellcome Trust Research ProgrammeKilifiKenya
- Mbagathi County HospitalNairobiKenya
| | - Christine Manyasi
- KEMRI‐Wellcome Trust Research ProgrammeKilifiKenya
- Mbagathi County HospitalNairobiKenya
| | - Laura Mwalekwa
- KEMRI‐Wellcome Trust Research ProgrammeKilifiKenya
- Coast General HospitalMombasaKenya
| | | | - Bernhards Ogutu
- Center for Research in Therapeutic SciencesStrathmore UniversityNairobiKenya
- KEMRI‐Centre for Clinical ResearchNairobiKenya
| | | | - Karin Kipper
- Analytical Services International, St George's University of LondonLondonUK
- Institute of ChemistryUniversity of TartuTartuEstonia
| | - James A. Berkley
- KEMRI‐Wellcome Trust Research ProgrammeKilifiKenya
- The Childhood Acute Illness & Nutrition (CHAIN) NetworkNairobiKenya
- Centre for Tropical Medicine & Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
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81
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Lonsdale DO, Baker EH, Kipper K, Barker C, Philips B, Rhodes A, Sharland M, Standing JF. Scaling beta-lactam antimicrobial pharmacokinetics from early life to old age. Br J Clin Pharmacol 2018; 85:316-346. [PMID: 30176176 DOI: 10.1111/bcp.13756] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/02/2018] [Accepted: 08/22/2018] [Indexed: 12/13/2022] Open
Abstract
AIMS Beta-lactam dose optimization in critical care is a current priority. We aimed to review the pharmacokinetics (PK) of three commonly used beta-lactams (amoxicillin ± clavulanate, piperacillin-tazobactam and meropenem) to compare PK parameters reported in critically and noncritically ill neonates, children and adults, and to investigate whether allometric and maturation scaling principles could be applied to describe changes in PK parameters through life. METHODS A systematic review of PK studies of the three drugs was undertaken using MEDLINE and EMBASE. PK parameters and summary statistics were extracted and scaled using allometric principles to 70 kg individual for comparison. Pooled data were used to model clearance maturation and decline using a sigmoidal (Hill) function. RESULTS A total of 130 papers were identified. Age ranged from 29 weeks to 82 years and weight from 0.9-200 kg. PK parameters from critically ill populations were reported with wider confidence intervals than those in healthy volunteers, indicating greater PK variability in critical illness. The standard allometric size and sigmoidal maturation model adequately described increasing clearance in neonates, and a sigmoidal model was also used to describe decline in older age. Adult weight-adjusted clearance was achieved at approximately 2 years postmenstrual age. Changes in volume of distribution were well described by the standard allometric model, although amoxicillin data suggested a relatively higher volume of distribution in neonates. CONCLUSIONS Critical illness is associated with greater PK variability than in healthy volunteers. The maturation models presented will be useful for optimizing beta-lactam dosing, although a prospective, age-inclusive study is warranted for external validation.
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Affiliation(s)
- Dagan O Lonsdale
- Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK
| | - Emma H Baker
- Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK
| | - Karin Kipper
- Institute for Infection and Immunity, St George's, University of London, London, UK.,Institute of Chemistry, University of Tartu, Tartu, Estonia.,Analytical Services International Ltd
| | - Charlotte Barker
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Barbara Philips
- Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK
| | - Andrew Rhodes
- St George's University Hospitals NHS Foundation Trust, London, UK
| | - Mike Sharland
- Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK
| | - Joseph F Standing
- Institute for Infection and Immunity, St George's, University of London, London, UK.,St George's University Hospitals NHS Foundation Trust, London, UK.,UCL Great Ormond Street Institute of Child Health, London, UK.,Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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82
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Bonate PL, Wang T, Passier P, Bagchus W, Burt H, Lüpfert C, Abla N, Kovac J, Keiser J. Extrapolation of praziquantel pharmacokinetics to a pediatric population: a cautionary tale. J Pharmacokinet Pharmacodyn 2018; 45:747-762. [PMID: 30218416 PMCID: PMC6182730 DOI: 10.1007/s10928-018-9601-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 07/13/2018] [Indexed: 11/29/2022]
Abstract
L-praziquantel (PZQ) pharmacokinetic data were analyzed from two relative bioavailability Phase 1 studies in adult, healthy subjects with two new oral dispersion tablet (ODT) formulations of L-PZQ administered under various combinations of co-administration with food, water, and/or crushing. Linear mixed effects models adequately characterized the noncompartmental estimates of the pharmacokinetic profiles in both studies. Dose, food, and formulation were found to significantly affect L-PZQ exposure in both studies. The model for AUC was then extrapolated to children 2–5 years old accounting for enzyme maturation and weight. The predicted exposures were compared to an external Phase 1 study conducted by the Swiss Tropical and Public Health Institute using a currently marketed formulation (Cesol 600 mg immediate-release tablets) and found to be substantially lower than observed. A root cause analysis was completed to identify the reason for failure of the models. Various scenarios were proposed and tested. Two possible reasons for the failure were identified. One reason was that the model did not account for the reduced hepatic clearance seen in patients compared to the healthy volunteer population used to build the model. The second possible reason was that PZQ absorption appears sensitive to meal composition and the model did not account for differences in meals between a standardized Phase 1 unit and clinical sites in Africa. Further studies are needed to confirm our hypotheses.
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Affiliation(s)
| | - Tianli Wang
- Astellas, 1 Astellas Way, Northbrook, IL, 60062, USA.,Alkermes, Waltham, MA, 02451, USA
| | - Paul Passier
- Astellas, 1 Astellas Way, Northbrook, IL, 60062, USA.,Galapagos BV, Zernikedreef 16, Leiden, The Netherlands
| | - Wilhelmina Bagchus
- Merck Serono SA, Merck Institute for Pharmacometrics (A Subsidiary of Merck KGaA, Darmstadt, Germany), Lausanne, Switzerland
| | - Howard Burt
- Simcyp (a Certara company), Blades Enterprise Centre, John Street, Sheffield, S2 4SU, UK
| | - Christian Lüpfert
- Merck KGaA, Translational Quantitative Pharmacology, Frankfurter Str. 250, 64293, Darmstadt, Germany
| | - Nada Abla
- Merck Global Health Institute, Ares Trading S.A. (A Subsidiary of Merck KGaA, Darmstadt, Germany), 1262, Eysins, Switzerland
| | - Jana Kovac
- Swiss Tropical and Public Health Institute, Socinstr. 57, CH-4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Socinstr. 57, CH-4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
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83
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Standing JF, Anderson BJ, Hennig S, Holford NH, Johnston TN, Knibbe CAJ, Lonsdale DO, Rostami-Hodjegan A. Comment on "Effect of Age-Related Factors on the Pharmacokinetics of Lamotrigine and Potential Implications for Maintenance Dose Optimisation in Future Clinical Trials". Clin Pharmacokinet 2018; 57:1471-1472. [PMID: 30027513 DOI: 10.1007/s40262-018-0697-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Joseph F Standing
- UCL Great Ormond Street Institute for Child Health, Room 661, London, WC1N 1EH, UK.
| | - Brian J Anderson
- Department of Anaesthesia, University of Auckland, Auckland, New Zealand
| | - Stefanie Hennig
- School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
| | - Nick H Holford
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | | | - Catherijne A J Knibbe
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, University of Leiden, Leiden, The Netherlands
| | - Dagan O Lonsdale
- Department of Clinical Pharmacology, Institute for Infection and Immunity, St George's University of London, London, UK
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, Manchester, UK
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84
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Barker CIS, Standing JF, Kelly LE, Hanly Faught L, Needham AC, Rieder MJ, de Wildt SN, Offringa M. Pharmacokinetic studies in children: recommendations for practice and research. Arch Dis Child 2018; 103:695-702. [PMID: 29674514 PMCID: PMC6047150 DOI: 10.1136/archdischild-2017-314506] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 03/08/2018] [Accepted: 03/14/2018] [Indexed: 12/11/2022]
Abstract
Optimising the dosing of medicines for neonates and children remains a challenge. The importance of pharmacokinetic (PK) and pharmacodynamic (PD) research is recognised both in medicines regulation and paediatric clinical pharmacology, yet there remain barriers to undertaking high-quality PK and PD studies. While these studies are essential in understanding the dose-concentration-effect relationship and should underpin dosing recommendations, this review examines how challenges affecting the design and conduct of paediatric pharmacological studies can be overcome using targeted pharmacometric strategies. Model-based approaches confer benefits at all stages of the drug life-cycle, from identifying the first dose to be used in children, to clinical trial design, and optimising the dosing regimens of older, off-patent medications. To benefit patients, strategies to ensure that new PK, PD and trial data are incorporated into evidence-based dosing recommendations are needed. This review summarises practical strategies to address current challenges, particularly the use of model-based (pharmacometric) approaches in study design and analysis. Recommendations for practice and directions for future paediatric pharmacological research are given, based on current literature and our joint international experience. Success of PK research in children requires a robust infrastructure, with sustainable funding mechanisms at its core, supported by political and regulatory initiatives, and international collaborations. There is a unique opportunity to advance paediatric medicines research at an unprecedented pace, bringing the age of evidence-based paediatric pharmacotherapy into sight.
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Affiliation(s)
- Charlotte I S Barker
- Infection, Inflammation and Rheumatology Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George’s University of London, London, UK,Paediatric Infectious Diseases Unit, St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Joseph F Standing
- Infection, Inflammation and Rheumatology Section, UCL Great Ormond Street Institute of Child Health, University College London, London, UK,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George’s University of London, London, UK
| | - Lauren E Kelly
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada,Clinical Trials Platform, George and Fay Yee Centre for Healthcare Innovation, Winnipeg, Manitoba, Canada
| | - Lauren Hanly Faught
- Departments of Paediatrics, Physiology and Pharmacology and Medicine, Western University, London, Ontario, Canada,Molecular Medicine Group, Robarts Research Institute, London, Ontario, Canada
| | - Allison C Needham
- Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael J Rieder
- Departments of Paediatrics, Physiology and Pharmacology and Medicine, Western University, London, Ontario, Canada,Molecular Medicine Group, Robarts Research Institute, London, Ontario, Canada
| | - Saskia N de Wildt
- Department of Pharmacology and Toxicology, Radboud University, Nijmegen, The Netherlands,Intensive Care and Department of Pediatric Surgery, Erasmus MC Sophia, Rotterdam, The Netherlands
| | - Martin Offringa
- Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada,Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
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85
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Advances in pharmacokinetic modeling: target controlled infusions in the obese. Curr Opin Anaesthesiol 2018; 31:415-422. [PMID: 29794852 DOI: 10.1097/aco.0000000000000619] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW The use of conventional pharmacokinetic parameters sets 'models' derived from nonobese patients has proven inadequate to administer intravenous anesthetics in the obese population and is commonly associated with higher than anticipated plasma propofol concentrations when used with target (plasma or effect site) controlled infusion pumps. In this review we will describe recent modeling strategies to characterize the disposition of intravenous anesthetics in the obese patient and will show clinically relevant aspects of new model's performance in the obese population. RECENT FINDINGS Because clearance of a drug increases in a nonlinear manner with weight, nonlinear relationships better scale infusion rates between lean and obese individuals. Allometric concepts have been successfully used to describe size-related nonlinear changes in clearances. Other nonlinear scaling options include the use of descriptors such as body surface area, lean body weight, fat-free mass, and normal fat mass. Newer pharmacokinetic models, determined from obese patient data, have been developed for propofol and remifentanil using allometric concepts and comprehensive size descriptors. SUMMARY Pharmacokinetic models to perform target-controlled infusion in the obese population should incorporate descriptors that reflect with greater precision the influence of body composition in volumes and clearances of each drug. It is our hope that commercially available pumps will soon incorporate these new models to improve the performance of this technique in the obese population.
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86
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Danielak D, Kasprzyk A, Wróbel T, Wachowiak J, Kałwak K, Główka F. Relationship between exposure to treosulfan and its monoepoxytransformer - An insight from population pharmacokinetic study in pediatric patients before hematopoietic stem cell transplantation. Eur J Pharm Sci 2018; 120:1-9. [PMID: 29705215 DOI: 10.1016/j.ejps.2018.04.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/09/2018] [Accepted: 04/23/2018] [Indexed: 11/27/2022]
Abstract
Treosulfan (TREO), a structural analog of busulfan, is currently studied as a myeloablative agent in conditioning regimens before hematopoietic stem cell transplantation in pediatric patients. High exposure to TREO (>1650 mg∗h/mL) might be related to early toxicity, especially skin toxicity and mucositis. The aim of the present study was to investigate a potential relationship between exposure to TREO and its monoepoxytransformer (S,S-EBDM), as well as variability of the pharmacokinetics of these entities by means of a population pharmacokinetic approach with a non-linear mixed-effects analysis. The study included data from 14 children with malignant and non-malignant diseases treated with TREO in daily doses 10-14 g/m2. The parent-metabolite population pharmacokinetic model was developed in NONMEM 7.3 software. Upon the constructed model, an extensive simulation was performed to assess the correlation between exposure to TREO and S,S-EBDM. It was found that TREO and S,S-EBDM pharmacokinetics was best described with 2-compartmental and 1-compartmental linear models, respectively. The vast majority (>65%) of TREO was transformed to S,S-EBDM. Overall, a considerable interpatient variability of pharmacokinetic parameters was observed, especially the clearance of S,S-EBDM. A weak correlation was found between the exposure to TREO and S,S-EBDM (r = 0.1681, p < 0.0001). Also, patients with an exposure to TREO above 1650 mg∗h/mL were most likely to have also a high exposure to S,S-EBDM (35.38 μM∗h vs. 43.14 μM∗h, p < 0.0001). In summary, a parent-metabolite population pharmacokinetic model for TREO and S,S-EBDM was developed for the first time. It was shown that there is a weak correlation between exposure to TREO and S,S-EBDM. Therefore therapeutic drug monitoring of not only prodrug but also its active epoxide might be needed.
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Affiliation(s)
- Dorota Danielak
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, Święcickiego 6 St, 60-781 Poznań, Poland.
| | - Anna Kasprzyk
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, Święcickiego 6 St, 60-781 Poznań, Poland
| | - Tomasz Wróbel
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, Święcickiego 6 St, 60-781 Poznań, Poland
| | - Jacek Wachowiak
- Department of Pediatric Hematology, Oncology and Transplantology, Poznan University of Medical Sciences, 27/33 Szpitalna St, 60-572 Poznań, Poland.
| | - Krzysztof Kałwak
- Department of Pediatric Hematology, Oncology and Bone Marrow Transplantation, Wroclaw Medical University, 44 Bujwida St, 50-368 Wroclaw, Poland
| | - Franciszek Główka
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, Święcickiego 6 St, 60-781 Poznań, Poland.
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87
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Population Pharmacokinetic Properties of Sulfadoxine and Pyrimethamine: a Pooled Analysis To Inform Optimal Dosing in African Children with Uncomplicated Malaria. Antimicrob Agents Chemother 2018; 62:AAC.01370-17. [PMID: 29463542 PMCID: PMC5923181 DOI: 10.1128/aac.01370-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 02/09/2018] [Indexed: 02/07/2023] Open
Abstract
Sulfadoxine-pyrimethamine with amodiaquine is recommended by the World Health Organization as seasonal malaria chemoprevention for children aged 3 to 59 months in the sub-Sahel regions of Africa. Suboptimal dosing in children may lead to treatment failure and increased resistance. Pooled individual patient data from four previously published trials on the pharmacokinetics of sulfadoxine and pyrimethamine in 415 pediatric and 386 adult patients were analyzed using nonlinear mixed-effects modeling to evaluate the current dosing regimen and, if needed, to propose an optimized dosing regimen for children under 5 years of age. The population pharmacokinetics of sulfadoxine and pyrimethamine were both best described by a one-compartment disposition model with first-order absorption and elimination. Body weight, age, and nutritional status (measured as the weight-for-age Z-score) were found to be significant covariates. Allometric scaling with total body weight and the maturation of clearance in children by postgestational age improved the model fit. Underweight-for-age children were found to have 15.3% and 26.7% lower bioavailabilities of sulfadoxine and pyrimethamine, respectively, for each Z-score unit below -2. Under current dosing recommendations, simulation predicted that the median day 7 concentration was below the 25th percentile for a typical adult patient (50 kg) for sulfadoxine for patients in the weight bands of 8 to 9, 19 to 24, 46 to 49, and 74 to 79 kg and for pyrimethamine for patients in the weight bands of 8 to 9, 14 to 24, and 42 to 49 kg. An evidence-based dosing regimen was constructed that would achieve sulfadoxine and pyrimethamine exposures in young children and underweight-for-age young children that were similar to those currently seen in a typical adult.
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88
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Pharmacokinetics of Penicillin G in Preterm and Term Neonates. Antimicrob Agents Chemother 2018; 62:AAC.02238-17. [PMID: 29463540 DOI: 10.1128/aac.02238-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/09/2018] [Indexed: 11/20/2022] Open
Abstract
Group B streptococci are common causative agents of early-onset neonatal sepsis (EOS). Pharmacokinetic (PK) data for penicillin G have been described for extremely preterm neonates but have been poorly described for late-preterm and term neonates. Thus, evidence-based dosing recommendations are lacking. We describe the PK of penicillin G in neonates with a gestational age (GA) of ≥32 weeks and a postnatal age of <72 h. Penicillin G was administered intravenously at a dose of 25,000 or 50,000 IU/kg of body weight every 12 h (q12h). At steady state, PK blood samples were collected prior to and at 5 min, 1 h, 3 h, 8 h, and 12 h after injection. Noncompartmental PK analysis was performed with WinNonlin software. With those data in combination with data from neonates with a GA of ≤28 weeks, we developed a population PK model using NONMEM software and performed probability of target attainment (PTA) simulations. In total, 16 neonates with a GA of ≥32 weeks were included in noncompartmental analysis. The median volume of distribution (V) was 0.50 liters/kg (interquartile range, 0.42 to 0.57 liters/kg), the median clearance (CL) was 0.21 liters/h (interquartile range, 0.16 to 0.29 liters/kg), and the median half-life was 3.6 h (interquartile range, 3.2 to 4.3 h). In the population PK analysis that included 35 neonates, a two-compartment model best described the data. The final parameter estimates were 10.3 liters/70 kg and 29.8 liters/70 kg for V of the central and peripheral compartments, respectively, and 13.2 liters/h/70 kg for CL. Considering the fraction of unbound penicillin G to be 40%, the PTA of an unbound drug concentration that exceeds the MIC for 40% of the dosing interval was >90% for MICs of ≤2 mg/liter with doses of 25,000 IU/kg q12h. In neonates, regardless of GA, the PK parameters of penicillin G were similar. The dose of 25,000 IU/kg q12h is suggested for treatment of group B streptococcal EOS diagnosed within the first 72 h of life. (This study was registered with the EU Clinical Trials Register under EudraCT number 2012-002836-97.).
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89
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Tools for the Individualized Therapy of Teicoplanin for Neonates and Children. Antimicrob Agents Chemother 2017; 61:AAC.00707-17. [PMID: 28760897 PMCID: PMC5610524 DOI: 10.1128/aac.00707-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/14/2017] [Indexed: 02/06/2023] Open
Abstract
The aim of this study was to develop a population pharmacokinetic (PK) model for teicoplanin across childhood age ranges to be used as Bayesian prior information in the software constructed for individualized therapy. We developed a nonparametric population model fitted to PK data from neonates, infants, and older children. We then implemented this model in the BestDose multiple-model Bayesian adaptive control algorithm to show its clinical utility. It was used to predict the dosages required to achieve optimal teicoplanin predose targets (15 mg/liter) from day 3 of therapy. We performed individual simulations for an infant and a child from the original population, who provided early first dosing interval concentration-time data. An allometric model that used weight as a measure of size and that also incorporated renal function using the estimated glomerular filtration rate (eGFR), or the ratio of postnatal age (PNA) to serum creatinine concentration (SCr) for infants <3 months old, best described the data. The median population PK parameters were as follows: elimination rate constant (Ke) = 0.03 · (wt/70)−0.25 · Renal (h−1); V = 19.5 · (wt/70) (liters); Renal = eGFR0.07 (ml/min/1.73 m2), or Renal = PNA/SCr (μmol/liter). Increased teicoplanin dosages and alternative administration techniques (extended infusions and fractionated multiple dosing) were required in order to achieve the targets safely by day 3 in simulated cases. The software was able to predict individual measured concentrations and the dosages and administration techniques required to achieve the desired target concentrations early in therapy. Prospective evaluation is now needed in order to ensure that this individualized teicoplanin therapy approach is applicable in the clinical setting. (This study has been registered in the European Union Clinical Trials Register under EudraCT no. 2012-005738-12.)
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90
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A Population Pharmacokinetic Model of Gentamicin in Pediatric Oncology Patients To Facilitate Personalized Dosing. Antimicrob Agents Chemother 2017; 61:AAC.00205-17. [PMID: 28533244 DOI: 10.1128/aac.00205-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/13/2017] [Indexed: 11/20/2022] Open
Abstract
To ensure the safe and effective dosing of gentamicin in children, therapeutic drug monitoring (TDM) is recommended. TDM utilizing Bayesian forecasting software is recommended but is unavailable, as no population model that describes the pharmacokinetics of gentamicin in pediatric oncology patients exists. This study aimed to develop and externally evaluate a population pharmacokinetic model of gentamicin to support personalized dosing in pediatric oncology patients. A nonlinear mixed-effect population pharmacokinetic model was developed from retrospective data. Data were collected from 423 patients for model building and a further 52 patients for external evaluation. A two-compartment model with first-order elimination best described the gentamicin disposition. The final model included renal function (described by fat-free mass and postmenstrual age) and the serum creatinine concentration as covariates influencing gentamicin clearance (CL). Final parameter estimates were as follow CL, 5.77 liters/h/70 kg; central volume of distribution, 21.6 liters/70 kg; peripheral volume of distribution, 13.8 liters/70 kg; and intercompartmental clearance, 0.62 liter/h/70 kg. External evaluation suggested that current models developed in other pediatric cohorts may not be suitable for use in pediatric oncology patients, as they showed a tendency to overpredict the observations in this population. The final model developed in this study displayed good predictive performance during external evaluation (root mean square error, 46.0%; mean relative prediction error, -3.40%) and may therefore be useful for the personalization of gentamicin dosing in this cohort. Further investigations should focus on evaluating the clinical application of this model.
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91
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Holford NHG, Anderson BJ. Why standards are useful for predicting doses. Br J Clin Pharmacol 2017; 83:685-687. [PMID: 28155239 PMCID: PMC6436183 DOI: 10.1111/bcp.13230] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/30/2016] [Indexed: 01/08/2023] Open
Abstract
Germovsek and colleagues have recently concluded that a standard approach to modelling pharmacokinetics is not wrong and appears to be at least as useful as other ad hoc methods for describing drug concentrations. There are other advantages of this approach including learning about biology, comparing different studies, detecting errors and rationalizing dose prediction. A standard approach to size and maturation is not a panacea but provides the framework for challenging new ideas and supports a consistent method of dosing in patients of all ages.
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Affiliation(s)
- Nick H. G. Holford
- Department of Pharmacology & Clinical PharmacologyUniversity of AucklandNew Zealand
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92
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Germovsek E, Barker CIS, Sharland M, Standing JF. Scaling clearance in paediatric pharmacokinetics: All models are wrong, which are useful? Br J Clin Pharmacol 2016; 83:777-790. [PMID: 27767204 PMCID: PMC5346879 DOI: 10.1111/bcp.13160] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 10/06/2016] [Accepted: 10/15/2016] [Indexed: 12/11/2022] Open
Abstract
Linked Articles This article is commented on in the editorial by Holford NHG and Anderson BJ. Why standards are useful for predicting doses. Br J Clin Pharmacol 2017; 83: 685–7. doi: 10.1111/bcp.13230 Aim When different models for weight and age are used in paediatric pharmacokinetic studies it is difficult to compare parameters between studies or perform model‐based meta‐analyses. This study aimed to compare published models with the proposed standard model (allometric weight0.75 and sigmoidal maturation function). Methods A systematic literature search was undertaken to identify published clearance (CL) reports for gentamicin and midazolam and all published models for scaling clearance in children. Each model was fitted to the CL values for gentamicin and midazolam, and the results compared with the standard model (allometric weight exponent of 0.75, along with a sigmoidal maturation function estimating the time in weeks of postmenstrual age to reach half the mature value and a shape parameter). For comparison, we also looked at allometric size models with no age effect, the influence of estimating the allometric exponent in the standard model and, for gentamicin, using a fixed allometric exponent of 0.632 as per a study on glomerular filtration rate maturation. Akaike information criteria (AIC) and visual predictive checks were used for evaluation. Results No model gave an improved AIC in all age groups, but one model for gentamicin and three models for midazolam gave slightly improved global AIC fits albeit using more parameters: AIC drop (number of parameters), –4.1 (5), –9.2 (4), –10.8 (5) and –10.1 (5), respectively. The 95% confidence interval of estimated CL for all top performing models overlapped. Conclusion No evidence to reject the standard model was found; given the benefits of standardised parameterisation, its use should therefore be recommended.
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Affiliation(s)
- Eva Germovsek
- Inflammation, Infection and Rheumatology Section, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
| | - Charlotte I S Barker
- Inflammation, Infection and Rheumatology Section, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.,St George's University Hospitals NHS Foundation Trust, Blackshaw Road, London, UK
| | - Mike Sharland
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.,St George's University Hospitals NHS Foundation Trust, Blackshaw Road, London, UK
| | - Joseph F Standing
- Inflammation, Infection and Rheumatology Section, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK
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