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Hermann L, Schöning V, Dräger S, Rentsch K, Moser S, Gürtler N, Sendi P, Osthoff M, Hammann F. Population pharmacokinetics of flucloxacillin as intermittent bolus infusion in patients with Staphylococcus aureus bloodstream infection. J Antimicrob Chemother 2024; 79:2031-2039. [PMID: 38946285 DOI: 10.1093/jac/dkae207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 06/06/2024] [Indexed: 07/02/2024] Open
Abstract
BACKGROUND Optimal antibiotic dosing for Staphylococcus aureus bloodstream infections (BSI) is still controversial. One reason is inter-individual variation in pharmacokinetics, which may be influenced by various patient-related factors, particularly in critically ill patients. OBJECTIVES To describe the population pharmacokinetics (PopPK) of the antibiotic flucloxacillin in patients with S. aureus BSI. Subsequently, we sought to translate the model into a user-friendly app for generating a priori and a posteriori time-concentration curves and dose recommendations to optimize dosing regimens. METHODS Total and unbound flucloxacillin concentrations were included from 49 patients from a prospective cohort study conducted during clinical routine, including non-critically ill and critically ill individuals who received intermittent bolus applications. These data were analysed using non-linear mixed-effects modelling. RESULTS Most patients (98%) were treated with 2 g of flucloxacillin every 4 h. We developed a joint model that simultaneously described total and unbound concentrations. The model included an allometric effect of glomerular filtration rate on clearance and albumin on the albumin dissociation constant. The latter was especially important, as in our population the unbound fraction was higher at 11.5% (16.7% for critically ill patients) compared with reported values of approximately 5%. Based on our joint model, we developed a web-based app for optimizing dosing regimens of flucloxacillin. CONCLUSIONS By utilizing data from clinical routine, we were able to create a predictive PopPK model of flucloxacillin and identify influential covariates. The web-based app is currently being validated in a clinical trial.
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Affiliation(s)
- Laura Hermann
- Division of Clinical Pharmacology and Toxicology, Department of Internal Medicine, University Hospital Bern, Bern, Switzerland
| | - Verena Schöning
- Division of Clinical Pharmacology and Toxicology, Department of Internal Medicine, University Hospital Bern, Bern, Switzerland
| | - Sarah Dräger
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Katharina Rentsch
- Division of Laboratory Medicine, University Hospital Basel, Basel, Switzerland
| | - Stephan Moser
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
| | - Nicolas Gürtler
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
| | - Parham Sendi
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Michael Osthoff
- Division of Internal Medicine, University Hospital Basel, Basel, Switzerland
- Department of Clinical Research, University of Basel, Basel, Switzerland
- Department of Internal Medicine, Cantonal Hospital Winterthur, Winterthur, Switzerland
| | - Felix Hammann
- Division of Clinical Pharmacology and Toxicology, Department of Internal Medicine, University Hospital Bern, Bern, Switzerland
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2
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Novy E, Liu X, Hernández-Mitre MP, Belveyre T, Scala-Bertola J, Roberts JA, Parker SL. Population pharmacokinetics of prophylactic cefoxitin in elective bariatric surgery patients: a prospective monocentric study. Anaesth Crit Care Pain Med 2024; 43:101376. [PMID: 38494157 DOI: 10.1016/j.accpm.2024.101376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 02/19/2024] [Accepted: 03/12/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND This study describes the population pharmacokinetics of cefoxitin in obese patients undergoing elective bariatric surgery and evaluates different dosing regimens for achievement of pre-defined target exposures. METHODS Serial blood samples were collected during surgery with relevant clinical data. Total serum cefoxitin concentrations were measured by chromatographic assay and analysed using a population PK approach with Pmetrics®. The cefoxitin unbound fraction (fu) was estimated. Dosing simulations were performed to ascertain the probability of target attainment (PTA) to achieve cefoxitin fu above minimum inhibitory concentrations (MIC) from surgical incision to wound closure. Fractional target attainment (FTA) was calculated against MIC distributions of common pathogens. RESULTS A total of 123 obese patients (median BMI 44.3 kg/m2) were included with 381 cefoxitin concentration values. Cefoxitin was best described by a one-compartment model, with a mean clearance and volume of distribution of 10.9 ± 6.1 L/h and 23.4 ± 10.5 L, respectively. In surgery <2 h, a 2 and a 4 g doses were sufficient for an MIC up to 4 and 8 mg/L (fu 50%), respectively. In prolonged surgery (2-4 h), only continuous infusion enabled optimal PTA for an MIC up to 16 mg/L. Optimal FTAs were obtained against Staphylococcus aureus and Escherichia Coli only when simulating with 50% cefoxitin protein binding (intermittent regimen) and regardless of the protein binding for the continuous infusion. CONCLUSION Intermittent dosing regimens resulted in optimal FTAs against susceptible MIC distributions of S. aureus and E. coli when simulating with 50% cefoxitin protein binding. Continuous infusion of cefoxitin may improve FTA regardless of protein binding. STUDY REGISTRATION Registration on ClinicalTrials.gov, NCT03306290.
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Affiliation(s)
- Emmanuel Novy
- Department of Anaesthesiology Critical Care and Perioperative Medicine, Nancy University Hospital, University of Lorraine, Vandoeuvre-Lès-Nancy, 54500, France; UR SIMPA, Université de Lorraine, 54000, Nancy, France; UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, 4029, Australia.
| | - Xin Liu
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, 4029, Australia
| | | | - Thibaut Belveyre
- Department of Anaesthesiology Critical Care and Perioperative Medicine, Nancy University Hospital, University of Lorraine, Vandoeuvre-Lès-Nancy, 54500, France
| | - Julien Scala-Bertola
- Department of Clinical Pharmacology and Toxicology, Nancy University Hospital, Vandoeuvre-Lès-Nancy, 54500, France; CNRS, IMoPA, Université de Lorraine, 54000, Nancy, France
| | - Jason A Roberts
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, 4029, Australia; Division of Anaesthesiology Critical Care Emergency & Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, 30029, France; Herston Infectious Disease Institute (HeiDI), Metro North Health, Brisbane, Australia
| | - Suzanne L Parker
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, 4029, Australia
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Courville J, Roupe K, Arold G. Re-discover the value of protein binding assessments in hepatic and renal impairment studies and its contributions in drug labels and dose decisions. Clin Transl Sci 2024; 17:e13810. [PMID: 38716900 PMCID: PMC11077687 DOI: 10.1111/cts.13810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 03/05/2024] [Accepted: 04/12/2024] [Indexed: 05/12/2024] Open
Abstract
One of the key pharmacokinetic properties of most small molecule drugs is their ability to bind to serum proteins. Unbound or free drug is responsible for pharmacological activity while the balance between free and bound drug can impact drug distribution, elimination, and other safety parameters. In the hepatic impairment (HI) and renal impairment (RI) clinical studies, unbound drug concentration is often assessed; however, the relevance and impact of the protein binding (PB) results is largely limited. We analyzed published clinical safety and pharmacokinetic studies in subjects with HI or RI with PB assessment up to October 2022 and summarized the contribution of PB results on their label dose recommendations. Among drugs with HI publication, 32% (17/53) associated product labels include PB results in HI section. Of these, the majority (9/17, 53%) recommend dose adjustments consistent with observed PB change. Among drugs with RI publication, 27% (12/44) of associated product labels include PB results in RI section with the majority (7/12, 58%) recommending no dose adjustment, consistent with the reported absence of PB change. PB results were found to be consistent with a tailored dose recommendation in 53% and 58% of the approved labels for HI and RI section, respectively. We further discussed the interpretation challenges of PB results, explored treatment decision factors including total drug concentration, exposure-response relationships, and safety considerations in these case examples. Collectively, comprehending the alterations in free drug levels in HI and RI informs treatment decision through a risk-based approach.
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Affiliation(s)
- Jocelyn Courville
- Clinical Pharmacology—Drug Development SolutionICON plcBlue BellPennsylvaniaUSA
| | - Kathryn Roupe
- Clinical Pharmacology, PharmacokineticsWorldwide Clinical TrialsAustinTexasUSA
| | - Gerhard Arold
- Clinical Pharmacology—Drug Development SolutionICON plcLangenGermany
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4
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Mekking XM, Velthoven-Graafland K, Teulen MJA, Brüggemann RJM, te Brake LHM, Jager NGL. Development and validation of an UPLC-MS/MS assay for the simultaneous quantification of seven commonly used antibiotics in human plasma and its application in therapeutic drug monitoring. J Antimicrob Chemother 2024; 79:883-890. [PMID: 38416407 PMCID: PMC10984926 DOI: 10.1093/jac/dkae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/02/2024] [Indexed: 02/29/2024] Open
Abstract
OBJECTIVE To develop and validate an UPLC-MS/MS assay for simultaneous determination of the total concentration of ceftazidime, ciprofloxacin, flucloxacillin, piperacillin, tazobactam, sulfamethoxazole, N-acetyl sulfamethoxazole and trimethoprim, and the protein-unbound concentration of flucloxacillin, in human plasma to be used for research and clinical practice. METHODS Sample pretreatment included protein precipitation with methanol. For the measurement of protein-unbound flucloxacillin, ultrafiltration was performed at physiological temperature. For all compounds, a stable isotopically labelled internal standard was used. Reliability of the results was assessed by participation in an international quality control programme. RESULTS The assay was successfully validated according to the EMA guidelines over a concentration range of 0.5-100 mg/L for ceftazidime, 0.05-10 mg/L for ciprofloxacin, 0.4-125 mg/L for flucloxacillin, 0.2-60 mg/L for piperacillin, 0.15-30 mg/L for tazobactam, 1-200 mg/L for sulfamethoxazole and N-acetyl sulfamethoxazole, 0.05-10 mg/L for trimethoprim and 0.10-50 mg/L for unbound flucloxacillin. For measurement of total concentrations, the within- and between-day accuracy ranged from 90.0% to 109%, and 93.4% to 108%, respectively. Within- and between-day precision (variation coefficients, CVs) ranged from 1.70% to 11.2%, and 0.290% to 5.30%, respectively. For unbound flucloxacillin, within-day accuracy ranged from 103% to 106% and between-day accuracy from 102% to 105%. The within- and between-day CVs ranged from 1.92% to 7.11%. Results of the international quality control programme showed that the assay is reliable. CONCLUSIONS The method provided reliable, precise and accurate measurement of seven commonly prescribed antibiotics, including the unbound concentration of flucloxacillin. This method is now routinely applied in research and clinical practice.
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Affiliation(s)
- Xin Meng Mekking
- School of Pharmacy, Utrecht University, Leuvenlaan 4, 3584 CE, Utrecht, The Netherlands
| | - Kirsten Velthoven-Graafland
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Marga J A Teulen
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Lindsey H M te Brake
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Nynke G L Jager
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
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Barker CIS, Kipper K, Lonsdale DO, Wright K, Thompson G, Kim M, Turner MA, Johnston A, Sharland M, Standing JF. The Neonatal and Paediatric Pharmacokinetics of Antimicrobials study (NAPPA): investigating amoxicillin, benzylpenicillin, flucloxacillin and piperacillin pharmacokinetics from birth to adolescence. J Antimicrob Chemother 2023; 78:2148-2161. [PMID: 37531085 PMCID: PMC10477139 DOI: 10.1093/jac/dkad196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 06/09/2023] [Indexed: 08/03/2023] Open
Abstract
BACKGROUND Pharmacokinetic (PK) data underlying paediatric penicillin dosing remain limited, especially in critical care. OBJECTIVES The primary objective of the Neonatal and Paediatric Pharmacokinetics of Antimicrobials study (NAPPA) was to characterize PK profiles of commonly used penicillins using data obtained during routine care, to further understanding of PK variability and inform future evidence-based dosing. METHODS NAPPA was a multicentre study of amoxicillin, co-amoxiclav, benzylpenicillin, flucloxacillin and piperacillin/tazobactam. Patients were recruited with informed consent. Antibiotic dosing followed standard of care. PK samples were obtained opportunistically or at optimal times, frozen and analysed using UPLC with tandem MS. Pharmacometric analysis was undertaken using NONMEM software (v7.3). Model-based simulations (n = 10 000) tested PTA with British National Formulary for Children (BNFC) and WHO dosing. The study had ethical approval. RESULTS For the combined IV PK model, 963 PK samples from 370 participants were analysed simultaneously incorporating amoxicillin, benzylpenicillin, flucloxacillin and piperacillin data. BNFC high-dose regimen simulations gave these PTA results (median fT>MIC at breakpoints of specified pathogens): amoxicillin 100% (Streptococcus pneumoniae); benzylpenicillin 100% (Group B Streptococcus); flucloxacillin 48% (MSSA); and piperacillin 100% (Pseudomonas aeruginosa). Oral population PK models for flucloxacillin and amoxicillin enabled estimation of first-order absorption rate constants (1.16 h-1 and 1.3 h-1) and bioavailability terms (62.7% and 58.7%, respectively). CONCLUSIONS NAPPA represents, to our knowledge, the largest prospective combined paediatric penicillin PK study undertaken to date, and the first paediatric flucloxacillin oral PK model. The PTA results provide evidence supportive of BNFC high-dose IV regimens for amoxicillin, benzylpenicillin and piperacillin.
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Affiliation(s)
- Charlotte I S Barker
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
- Paediatric Infectious Diseases Department, St George’s University Hospitals NHS Foundation Trust, London, UK
- Infection, Immunity and Inflammation Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Department of Medical & Molecular Genetics, King’s College London, London, UK
| | - Karin Kipper
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
- Analytical Services International, St George’s, University of London, London, UK
- Analytical Chemistry Department, Epilepsy Society, Chesham Lane, Chalfont St Peter, Buckinghamshire, UK
- Institute of Chemistry, University of Tartu, Tartu, Estonia
| | - Dagan O Lonsdale
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
- Paediatric Infectious Diseases Department, St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Kirstie Wright
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
| | - Georgina Thompson
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
| | - Min Kim
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
- Infection, Immunity and Inflammation Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Mark A Turner
- Department of Women’s and Children’s Health, University of Liverpool, Liverpool Health Partners, Liverpool, UK
| | - Atholl Johnston
- Analytical Services International, St George’s, University of London, London, UK
- Clinical Pharmacology, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Mike Sharland
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
- Paediatric Infectious Diseases Department, St George’s University Hospitals NHS Foundation Trust, London, UK
| | - Joseph F Standing
- Centre for Neonatal and Paediatric Infection, Level 2 Jenner Wing, Institute for Infection and Immunity, St George’s, University of London SW17 0RE, London, UK
- Infection, Immunity and Inflammation Research & Teaching Department, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Pharmacy Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
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Developmental Pharmacokinetics of Antibiotics Used in Neonatal ICU: Focus on Preterm Infants. Biomedicines 2023; 11:biomedicines11030940. [PMID: 36979919 PMCID: PMC10046592 DOI: 10.3390/biomedicines11030940] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/22/2023] Open
Abstract
Neonatal Infections are among the most common reasons for admission to the intensive care unit. Neonatal sepsis (NS) significantly contributes to mortality rates. Empiric antibiotic therapy of NS recommended by current international guidelines includes benzylpenicillin, ampicillin/amoxicillin, and aminoglycosides (gentamicin). The rise of antibacterial resistance precipitates the growth of the use of antibiotics of the Watch (second, third, and fourth generations of cephalosporines, carbapenems, macrolides, glycopeptides, rifamycins, fluoroquinolones) and Reserve groups (fifth generation of cephalosporines, oxazolidinones, lipoglycopeptides, fosfomycin), which are associated with a less clinical experience and higher risks of toxic reactions. A proper dosing regimen is essential for effective and safe antibiotic therapy, but its choice in neonates is complicated with high variability in the maturation of organ systems affecting drug absorption, distribution, metabolism, and excretion. Changes in antibiotic pharmacokinetic parameters result in altered efficacy and safety. Population pharmacokinetics can help to prognosis outcomes of antibiotic therapy, but it should be considered that the neonatal population is heterogeneous, and this heterogeneity is mainly determined by gestational and postnatal age. Preterm neonates are common in clinical practice, and due to the different physiology compared to the full terms, constitute a specific neonatal subpopulation. The objective of this review is to summarize the evidence about the developmental changes (specific for preterm and full-term infants, separately) of pharmacokinetic parameters of antibiotics used in neonatal intensive care units.
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7
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Hypoalbuminemia and Pharmacokinetics: When the Misunderstanding of a Fundamental Concept Leads to Repeated Errors over Decades. Antibiotics (Basel) 2023; 12:antibiotics12030515. [PMID: 36978382 PMCID: PMC10044130 DOI: 10.3390/antibiotics12030515] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/17/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Surprisingly, misinterpretation of the influence of hypoalbuminemia on pharmacokinetics and the clinical effects of drugs seems to be a current problem, even though hypoalbuminemia has no impact on the pharmacologically active exposure. Exceptions to this fact are highly protein-bound anaesthetics with high elimination capacity (i.e., <5 drugs on the market). To assess the frequency of misinterpretation of the influence of hypoalbuminemia on pharmacokinetics and the clinical effects of drugs between 1975 and 2021, a PubMed literature review was conducted. Each paragraph on albumin binding was classified as correct, ambiguous or incorrect, creating two acceptable categories: (1) content without any errors, and (2) content containing some incorrect and/or ambiguous statements. The analyses of these articles showed that fewer than 11% of articles contained no interpretation errors. In order to contain this misinterpretation, several measures are proposed: (1) Make the message accessible to a wide audience by offering a simplified and didactic video representation of the lack of impact of albumin binding to drugs. (2) Precise terminology (unbound/free form/concentration) should be used for highly bound drugs. (3) Unbound/free forms should be systematically quantified for highly plasma protein bound drugs for clinical trials as well as for therapeutic drug monitoring.
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Meenks SD, Punt N, le Noble JLML, Foudraine NA, Neef K, Janssen PKC. Target attainment and population pharmacokinetics of flucloxacillin in critically ill patients: a multicenter study. Crit Care 2023; 27:82. [PMID: 36869388 PMCID: PMC9982780 DOI: 10.1186/s13054-023-04353-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/08/2023] [Indexed: 03/05/2023] Open
Abstract
PURPOSE Insufficient antimicrobial exposure has been associated with worse clinical outcomes. Reportedly, flucloxacillin target attainment in critically ill patients was heterogeneous considering the study population selection and reported target attainment percentages. Therefore, we assessed flucloxacillin population pharmacokinetics (PK) and target attainment in critically ill patients. METHODS This prospective, multicenter, observational study was conducted from May 2017 to October 2019 and included adult, critically ill patients administered flucloxacillin intravenously. Patients with renal replacement therapy or liver cirrhosis were excluded. We developed and qualified an integrated PK model for total and unbound serum flucloxacillin concentrations. Monte Carlo dosing simulations were performed to assess target attainment. The unbound target serum concentration was four times the minimum inhibitory concentration (MIC) for ≥ 50% of the dosing interval (ƒT>4xMIC ≥ 50%). RESULTS We analyzed 163 blood samples from 31 patients. A one-compartment model with linear plasma protein binding was selected as most appropriate. Dosing simulations revealed 26% ƒT>2 mg/L ≥ 50% following continuous infusion of 12 g flucloxacillin and 51% ƒT>2 mg/L ≥ 50% for 24 g. CONCLUSION Based on our dosing simulations, standard flucloxacillin daily doses of up to 12 g may substantially enhance the risk of underdosing in critically ill patients. Prospective validation of these model predictions is needed.
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Affiliation(s)
- Sjoerd D Meenks
- Department of Clinical Pharmacy and Toxicology, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands. .,Department of Clinical Pharmacy, Catharina Hospital Eindhoven, P.O. Box 1350, 5602 ZA, Eindhoven, The Netherlands. .,Department of Hospital Pharmacy, VieCuri Medical Center, 5900 BX, Venlo, The Netherlands.
| | - Nieko Punt
- Medimatics, 6229 HR, Maastricht, The Netherlands.,University Medical Center Groningen, Department of Clinical Pharmacy and Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Jos L M L le Noble
- Department of Intensive Care, VieCuri Medical Center, 5900 BX, Venlo, The Netherlands.,Department of Pharmacology and Toxicology, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Norbert A Foudraine
- Department of Intensive Care, VieCuri Medical Center, 5900 BX, Venlo, The Netherlands
| | - Kees Neef
- Department of Clinical Pharmacy and Toxicology, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.,Department of Pharmacology and Toxicology, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Paddy K C Janssen
- Department of Clinical Pharmacy and Toxicology, Maastricht University Medical Center+, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.,Department of Hospital Pharmacy, VieCuri Medical Center, 5900 BX, Venlo, The Netherlands
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Ngougni Pokem P, Matzneller P, Vervaeke S, Wittebole X, Goeman L, Coessens M, Cottone E, Capron A, Wulkersdorfer B, Wallemacq P, Mouton JW, Muller AE, Zeitlinger M, Laterre PF, Tulkens PM, Van Bambeke F. Binding of temocillin to plasma proteins in vitro and in vivo: the importance of plasma protein levels in different populations and of co-medications. J Antimicrob Chemother 2022; 77:2742-2753. [PMID: 36018077 DOI: 10.1093/jac/dkac286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/28/2022] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Temocillin plasma protein binding (PPB) in healthy individuals is reported to be ∼85% but had not been studied in patients. OBJECTIVES To obtain normative data on temocillin PPB in patients in relation to infection and impact of co-medications widely used in ICU. METHODS Plasma was obtained from healthy individuals (Group #1), non-ICU patients with UTI (Group #2), ICU patients with suspected/confirmed ventriculitis (Group #3) or with sepsis/septic shock (Group #4). Total and unbound temocillin concentrations were measured in spiked samples from temocillin-naive donors (in vitro) or in plasma from temocillin-treated subjects (in vivo). The impact of diluting plasma, using pharmaceutical albumin, or adding drugs potentially competing for PPB was tested in spiked samples. Data were analysed using a modified Hill-Langmuir equation taking ligand depletion into account. RESULTS Temocillin PPB was saturable in all groups, both in vitro and in vivo. Maximal binding capacity (Bmax) was 1.2-2-fold lower in patients. At 20 and 200 mg/L (total concentrations), the unbound fraction reached 12%-29%, 23%-42% and 32%-52% in Groups #2, #3, #4. The unbound fraction was inversely correlated with albumin and C-reactive protein concentrations. Binding to albumin was 2-3-fold lower than in plasma and non-saturable. Drugs with high PPB but active at lower molar concentrations than temocillin caused minimal displacement, while fluconazole (low PPB but similar plasma concentrations to temocillin) increased up to 2-fold its unbound fraction. CONCLUSIONS Temocillin PPB is saturable, 2-4-fold lowered in infected patients in relation to disease severity (ICU admission, hypoalbuminaemia, inflammation) and only partially reproducible with albumin. Competition with other drugs must be considered for therapeutic concentrations to be meaningful.
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Affiliation(s)
- Perrin Ngougni Pokem
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Peter Matzneller
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna Austria
| | - Steven Vervaeke
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium
| | - Xavier Wittebole
- Department of Critical Care Medicine, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium
| | - Lieven Goeman
- Department of Urology, AZ Delta Hospital, Roeselare, Belgium
| | - Marie Coessens
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium
| | - Eleonora Cottone
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium
| | - Arnaud Capron
- Department of Clinical Chemistry, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium
| | | | - Pierre Wallemacq
- Department of Clinical Chemistry, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium
| | - Johan W Mouton
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Anouk E Muller
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.,Department of Medical Microbiology, Haaglanden Medical Centre, The Hague, The Netherlands
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna Austria
| | - Pierre François Laterre
- Department of Critical Care Medicine, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium
| | - Paul M Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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Pharmacodynamics of Flucloxacillin in a Neutropenic Murine Thigh Infection Model: A Piece of the Puzzle towards Evidence-Based Dosing. Antibiotics (Basel) 2022; 11:antibiotics11081049. [PMID: 36009918 PMCID: PMC9405042 DOI: 10.3390/antibiotics11081049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/25/2022] [Accepted: 08/01/2022] [Indexed: 12/22/2022] Open
Abstract
For decades, flucloxacillin has been used to treat methicillin-susceptible Staphylococcus aureus (MSSA). Little is still known about its pharmacodynamics (PD). The present study aimed to determine the pharmacokinetic (PK)/PD index and the PD-index value minimally required for efficacy. MICs of 305 MSSA isolates were measured to determine the wild-type distribution. The PD of 8 S. aureus, 1 S. pyogenes, and 1 S. agalactiae isolates were evaluated in a neutropenic murine thigh infection model. Two S. aureus isolates were used in a dose-fractionation study and a dose−response analysis was performed additionally in the in vivo model. Data were analyzed with a population PK and sigmoid maximum effect model. The end of the wild-type distribution was 1 mg/L. The percentage of time the unbound concentration was above MIC (%fT > MIC) was best correlated with efficacy. For S. aureus, median %fT > 0.25 × MIC required for 1-log reduction was 15%. The value for S. pyogenes was 10%fT > MIC and for S. agalactiae 22%fT > 0.25xMIC for a 1-log reduction. The effect of flucloxacillin reached a 2-log reduction of S. aureus at 20%fT > 0.25xMIC and also for S. pyogenes and S. agalactiae, a reduction was reached. These data may serve to optimize dosing regimens currently used in humans.
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Wallenburg E, Brüggemann RJM, Roberts JA, Jager NGL, Ulldemolins M, Wilkes S, Schouten J, Chin PKL, Ter Heine R. A meta-analysis of protein binding of flucloxacillin in healthy volunteers and hospitalized patients. Clin Microbiol Infect 2021; 28:446.e1-446.e7. [PMID: 34245903 DOI: 10.1016/j.cmi.2021.06.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/21/2021] [Accepted: 06/26/2021] [Indexed: 12/18/2022]
Abstract
OBJECTIVES The aim of this study was to develop a mechanistic protein-binding model to predict the unbound flucloxacillin concentrations in different patient populations. METHODS A mechanistic protein-binding model was fitted to the data using non-linear mixed-effects modelling. Data were obtained from four datasets, containing 710 paired total and unbound flucloxacillin concentrations from healthy volunteers, non-critically ill and critically ill patients. A fifth dataset with data from hospitalized patients was used for evaluation of our model. The predictive performance of the mechanistic model was evaluated and compared with the calculation of the unbound concentration with a fixed unbound fraction of 5%. Finally, we performed a fit-for-use evaluation, verifying whether the model-predicted unbound flucloxacillin concentrations would lead to clinically incorrect dose adjustments. RESULTS The mechanistic protein-binding model predicted the unbound flucloxacillin concentrations more accurately than assuming an unbound fraction of 5%. The mean prediction error varied between -26.2% to 27.8% for the mechanistic model and between -30.8% to 83% for calculation with a fixed factor of 5%. The normalized root mean squared error varied between 36.8% and 69% respectively between 57.1% and 134%. Predicting the unbound concentration with the use of the mechanistic model resulted in 6.1% incorrect dose adjustments versus 19.4% if calculated with a fixed unbound fraction of 5%. CONCLUSIONS Estimating the unbound concentration with a mechanistic protein-binding model outperforms the calculation with the use of a fixed protein binding factor of 5%, but neither demonstrates acceptable performance. When performing dose individualization of flucloxacillin, this should be done based on measured unbound concentrations rather than on estimated unbound concentrations from the measured total concentrations. In the absence of an assay for unbound concentrations, the mechanistic binding model should be preferred over assuming a fixed unbound fraction of 5%.
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Affiliation(s)
- Eveline Wallenburg
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands.
| | - Roger J M Brüggemann
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia; Departments of Pharmacy and Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Australia; Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Nynke G L Jager
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Marta Ulldemolins
- Infectious Diseases-Internal Medicine Departments, Hospital Universitari de Bellvitge, l'Hospitalet de Llobregat, Barcelona, Spain
| | - Sarah Wilkes
- Erasmus MC, University Medical Centre Rotterdam, Department of Hospital Pharmacy, Rotterdam, the Netherlands; Department of Clinical Pharmacy, Deventer Hospital, Deventer, the Netherlands
| | - Jeroen Schouten
- Department of Intensive Care, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Paul K L Chin
- Univeristy of Otago, Department of Clinical Pharmacology, Canterbury District Health Board, Christchurch, New Zealand
| | - Rob Ter Heine
- Department of Pharmacy and Radboud Institute for Health Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands
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