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De Sutter PJ, Rossignol P, Breëns L, Gasthuys E, Vermeulen A. Predicting Volume of Distribution in Neonates: Performance of Physiologically Based Pharmacokinetic Modelling. Pharmaceutics 2023; 15:2348. [PMID: 37765316 PMCID: PMC10536587 DOI: 10.3390/pharmaceutics15092348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/12/2023] [Accepted: 09/17/2023] [Indexed: 09/29/2023] Open
Abstract
The volume of distribution at steady state (Vss) in neonates is still often estimated through isometric scaling from adult values, disregarding developmental changes beyond body weight. This study aimed to compare the accuracy of two physiologically based pharmacokinetic (PBPK) Vss prediction methods in neonates (Poulin & Theil with Berezhkovskiy correction (P&T+) and Rodgers & Rowland (R&R)) with isometrical scaling. PBPK models were developed for 24 drugs using in-vitro and in-silico data. Simulations were done in Simcyp (V22) using predefined populations. Clinical data from 86 studies in neonates (including preterms) were used for comparison, and accuracy was assessed using (absolute) average fold errors ((A)AFEs). Isometric scaling resulted in underestimated Vss values in neonates (AFE: 0.61), and both PBPK methods reduced the magnitude of underprediction (AFE: 0.82-0.83). The P&T+ method demonstrated superior overall accuracy compared to isometric scaling (AAFE of 1.68 and 1.77, respectively), while the R&R method exhibited lower overall accuracy (AAFE: 2.03). Drug characteristics (LogP and ionization type) and inclusion of preterm neonates did not significantly impact the magnitude of error associated with isometric scaling or PBPK modeling. These results highlight both the limitations and the applicability of PBPK methods for the prediction of Vss in the absence of clinical data.
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Leegwater E, Wewerinke L, de Grauw AM, van Veen M, Storm BN, Kruizinga MD. Optimization of β-Lactam Dosing Regimens in Neonatal Infections: Continuous and Extended Administration versus Intermittent Administration. Clin Pharmacokinet 2023; 62:715-724. [PMID: 36972008 DOI: 10.1007/s40262-023-01230-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2023] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND OBJECTIVE In neonates, β-Lactam antibiotics are almost exclusively administered by intermittent infusion. However, continuous or prolonged infusion may be more beneficial because of the time-dependent antibacterial activity. In this pharmacokinetic/pharmacodynamic simulation study, we aimed to compare treatment with continuous, extended and intermittent infusion of β-lactam antibiotics for neonates with infectious diseases. METHODS We selected population pharmacokinetic models of penicillin G, amoxicillin, flucloxacillin, cefotaxime, ceftazidime and meropenem, and performed a Monte Carlo simulation with 30,000 neonates. Four different dosing regimens were simulated: intermittent infusion in 30 min, prolonged infusion in 4 h, continuous infusion, and continuous infusion with a loading dose. The primary endpoint was 90% probability of target attainment (PTA) for 100% ƒT>MIC during the first 48 h of treatment. RESULTS For all antibiotics except cefotaxime, continuous infusion with a loading dose resulted in a higher PTA compared with other dosing regimens. Sufficient exposure (PTA >90%) using continuous infusion with a loading dose was reached for amoxicillin (90.3%), penicillin G (PTA 98.4%), flucloxacillin (PTA 94.3%), cefotaxime (PTA 100%), and ceftazidime (PTA 100%). Independent of dosing regimen, higher meropenem (PTA for continuous infusion with a loading dose of 85.5%) doses might be needed to treat severe infections in neonates. Ceftazidime and cefotaxime dose might be unnecessarily high, as even with dose reductions, a PTA > 90% was retained. CONCLUSIONS Continuous infusion after a loading dose leads to a higher PTA compared with continuous, intermittent or prolonged infusion, and therefore has the potential to improve treatment with β-lactam antibiotics in neonates.
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Affiliation(s)
- Emiel Leegwater
- The Hague Hospital Pharmacy, The Hague, The Netherlands.
- Department of Hospital Pharmacy, Haga Teaching Hospital, The Hague, The Netherlands.
- Department of Infectious Diseases, Leiden University Medical Centre, Leiden University, Leiden, The Netherlands.
| | - Leo Wewerinke
- Juliana Children's Hospital, Haga Teaching Hospital, The Hague, The Netherlands
| | - Anne M de Grauw
- Juliana Children's Hospital, Haga Teaching Hospital, The Hague, The Netherlands
| | - Mirjam van Veen
- Juliana Children's Hospital, Haga Teaching Hospital, The Hague, The Netherlands
| | - Bert N Storm
- Department of Hospital Pharmacy, Haga Teaching Hospital, The Hague, The Netherlands
| | - Matthijs D Kruizinga
- Juliana Children's Hospital, Haga Teaching Hospital, The Hague, The Netherlands
- Department of Paediatrics, Willem Alexander Children's Hospital, Leiden University Medical Center, Leiden, The Netherlands
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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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Therapeutic drug monitoring of antimicrobial drugs in neonates. An opinion paper. Ther Drug Monit 2021; 44:65-74. [PMID: 34369442 PMCID: PMC8994040 DOI: 10.1097/ftd.0000000000000919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 06/29/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE Neonatal infections are associated with high morbidity and mortality rates. Optimal treatment of these infections requires knowledge of neonatal pharmacology and integration of neonatal developmental pharmacokinetics of antimicrobial drugs in the design of dosing regimens for use with different gestational and postnatal ages. Population pharmacokinetic (PK) and pharmacodynamic (PD) models are used to personalize the use of these drugs in these fragile patients. The final step to further minimize variability in an individual patient is therapeutic drug monitoring (TDM), where the same population PK/PD models are used in concert with optimally drawn blood samples to further fine-tune therapy. The purpose of this manuscript is to describe the present status and future role of model-based precision dosing and TDM of antimicrobial drugs in neonates. METHODS PubMed was searched for clinical trials or clinical studies of TDM in neonates. RESULTS A total of 447 papers were retrieved, of which 19 were concerned with antimicrobial drugs. Two papers (one aminoglycoside and one vancomycin) addressed the effects of TDM in neonates. We found that, in addition to aminoglycosides and vancomycin, TDM also plays a role in beta-lactam antibiotics and antifungal drugs. CONCLUSION There is a growing awareness that, in addition to aminoglycosides and vancomycin, the use of beta-lactam antibiotics, such as amoxicillin and meropenem, and other classes of antimicrobial drugs, such as antifungal drugs, may benefit from TDM. However, the added value must be shown. New analytical techniques and software development may greatly support these novel developments.
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Menezes MND, de Marco BA, Fiorentino FAM, Zimmermann A, Kogawa AC, Salgado HRN. Flucloxacillin: A Review of Characteristics, Properties and Analytical Methods. Crit Rev Anal Chem 2018; 49:67-77. [PMID: 29846080 DOI: 10.1080/10408347.2018.1468728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Bacterial resistance is a growing and worrying factor. The high reproducibility of these resistant microorganisms tends to influence the development of new drugs and research related to product quality control. Among the existing antimicrobials, flucloxacillin (FLU) was designed for oral and injectable administration with bactericidal activity. FLU sodium is the form used in pharmaceutical formulations. It is an antimicrobial resistant against penicillinase, an enzyme responsible for cleaving the beta-lactam ring of penicilins, which leads to inactivity of the drug. Qualitative and quantitative analyzes are essential to ensure quality of pharmaceuticals and health of the population. It is important that quality control is effective and appropriate, only then we can win the battle against microbial resistance. In this work, we want to highlight tthe characteristics of FLU as an important antibiotic and methods for the determination of FLU in pharmaceutical products and biological matrices. Among the analytical methods described in the literature for the determination of FLU, high performance liquid chromatography (HPLC) stands out. Anyway, this method uses toxic solvents (e.g. acetonitrile) long columns, which provide long runs, as well as produces large amounts of waste. Currently, the priority changed to develop ecologically correct, conscious and sustainable methods. This new view on analytical methods should be applied to FLU analyzes and used to develop and improve existing methods.
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Affiliation(s)
- Mariana Nunes de Menezes
- a Laboratory of Applied Pharmacology, School of Health Sciences , Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS , Porto Alegre , Brazil
| | - Bianca Aparecida de Marco
- b São Paulo StateUniversity (UNESP) , School of Pharmaceutical Sciences, Campus Araraquara , Araraquara , SP , Brazil
| | | | - Alexander Zimmermann
- c Division for Pathobiochemistry,Martin Luther University Halle-Wittenberg , Faculty of Medicine, Institute of Molecular Medicine, Charles-Tanford-Proteinzentrum, Weinberg Campus , Halle , Germany
| | - Ana Carolina Kogawa
- b São Paulo StateUniversity (UNESP) , School of Pharmaceutical Sciences, Campus Araraquara , Araraquara , SP , Brazil
| | - Hérida Regina Nunes Salgado
- b São Paulo StateUniversity (UNESP) , School of Pharmaceutical Sciences, Campus Araraquara , Araraquara , SP , Brazil
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Wilbaux M, Fuchs A, Samardzic J, Rodieux F, Csajka C, Allegaert K, van den Anker JN, Pfister M. Pharmacometric Approaches to Personalize Use of Primarily Renally Eliminated Antibiotics in Preterm and Term Neonates. J Clin Pharmacol 2016; 56:909-35. [PMID: 26766774 DOI: 10.1002/jcph.705] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 12/13/2022]
Abstract
Sepsis remains a major cause of mortality and morbidity in neonates, and, as a consequence, antibiotics are the most frequently prescribed drugs in this vulnerable patient population. Growth and dynamic maturation processes during the first weeks of life result in large inter- and intrasubject variability in the pharmacokinetics (PK) and pharmacodynamics (PD) of antibiotics. In this review we (1) summarize the available population PK data and models for primarily renally eliminated antibiotics, (2) discuss quantitative approaches to account for effects of growth and maturation processes on drug exposure and response, (3) evaluate current dose recommendations, and (4) identify opportunities to further optimize and personalize dosing strategies of these antibiotics in preterm and term neonates. Although population PK models have been developed for several of these drugs, exposure-response relationships of primarily renally eliminated antibiotics in these fragile infants are not well understood, monitoring strategies remain inconsistent, and consensus on optimal, personalized dosing of these drugs in these patients is absent. Tailored PK/PD studies and models are useful to better understand relationships between drug exposures and microbiological or clinical outcomes. Pharmacometric modeling and simulation approaches facilitate quantitative evaluation and optimization of treatment strategies. National and international collaborations and platforms are essential to standardize and harmonize not only studies and models but also monitoring and dosing strategies. Simple bedside decision tools assist clinical pharmacologists and neonatologists in their efforts to fine-tune and personalize the use of primarily renally eliminated antibiotics in term and preterm neonates.
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Affiliation(s)
- Mélanie Wilbaux
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland
| | - Aline Fuchs
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland
| | - Janko Samardzic
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Institute of Pharmacology, Clinical Pharmacology and Toxicology, Medical Faculty, University of Belgrade, Belgrade, Serbia
| | - Frédérique Rodieux
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland
| | - Chantal Csajka
- Division of Clinical Pharmacology, Service of Biomedicine, Department of Laboratory, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.,Department of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven, Belgium.,Intensive Care and Department of Surgery, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Johannes N van den Anker
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Intensive Care and Department of Surgery, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.,Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA
| | - Marc Pfister
- Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Quantitative Solutions LP, Menlo Park, CA, USA
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7
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Effective CSF concentrations achieved with continuous-infusion flucloxacillin in a child. Eur J Clin Pharmacol 2015; 71:1535-7. [DOI: 10.1007/s00228-015-1928-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 08/16/2015] [Indexed: 10/23/2022]
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van Maarseveen EM, Bouma A, Touw DJ, Neef C, van Zanten ARH. Design and prospective validation of a dosing instrument for continuous infusion of vancomycin: a within-population approach. Eur J Clin Pharmacol 2014; 70:1353-9. [PMID: 25168621 DOI: 10.1007/s00228-014-1742-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 08/20/2014] [Indexed: 11/26/2022]
Abstract
INTRODUCTION The clinical application of continuous infusion (CoI) of vancomycin has gained interest in recent years. Since no international guidelines on initial dosing of vancomycin CoI exist, there is a need for methods to facilitate the switch from intermittent to continuous vancomycin dosing algorithms in clinically infected populations. Therefore, the aim of this study was to design and validate an a priori dosing schedule for CoI of vancomycin in clinical practice. METHODS A dosing table for CoI of vancomycin based on estimated glomerular filtration rate (eGFR) was developed by simulation of continuous infusion of vancomycin using pharmacokinetic (PK) software and a PK population model designed from historical within-population data in intermittently dosed patients. The target range for the first vancomycin serum concentrations drawn approximately 24 h after start of infusion' (C24) was set at 15-20 mg/L corresponding with an area under the curve (AUC) of at least 350 mg·h·L(-1). The performance of the dosing schedule was primarily assessed by describing the percentages of patients attaining the predefined target. RESULTS An eGFR-derived dosing schedule for CoI of vancomycin was established and implemented in clinical practice. Prospective assessment in 35 general ward and 45 intensive care unit patients showed that the C24 target was reached in 69 and 63 % and the AUC target was attained in 80 and 72 % of patients, respectively. CONCLUSIONS An easy method to design and validate an eGFR-derived dosing algorithm for the continuous infusion of vancomycin to switch from intermittent to continuous dosing of vancomycin was developed.
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Affiliation(s)
- Erik M van Maarseveen
- Department of Clinical Pharmacy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands,
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Barker CIS, Germovsek E, Hoare RL, Lestner JM, Lewis J, Standing JF. Pharmacokinetic/pharmacodynamic modelling approaches in paediatric infectious diseases and immunology. Adv Drug Deliv Rev 2014; 73:127-39. [PMID: 24440429 PMCID: PMC4076844 DOI: 10.1016/j.addr.2014.01.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 12/09/2013] [Accepted: 01/11/2014] [Indexed: 02/02/2023]
Abstract
Pharmacokinetic/pharmacodynamic (PKPD) modelling is used to describe and quantify dose-concentration-effect relationships. Within paediatric studies in infectious diseases and immunology these methods are often applied to developing guidance on appropriate dosing. In this paper, an introduction to the field of PKPD modelling is given, followed by a review of the PKPD studies that have been undertaken in paediatric infectious diseases and immunology. The main focus is on identifying the methodological approaches used to define the PKPD relationship in these studies. The major findings were that most studies of infectious diseases have developed a PK model and then used simulations to define a dose recommendation based on a pre-defined PD target, which may have been defined in adults or in vitro. For immunological studies much of the modelling has focused on either PK or PD, and since multiple drugs are usually used, delineating the relative contributions of each is challenging. The use of dynamical modelling of in vitro antibacterial studies, and paediatric HIV mechanistic PD models linked with the PK of all drugs, are emerging methods that should enhance PKPD-based recommendations in the future.
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Affiliation(s)
- Charlotte I S Barker
- Paediatric Infectious Diseases Research Group, Division of Clinical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK; Infectious Diseases and Microbiology Unit, University College London, Institute of Child Health, London WC1N 1EH, UK
| | - Eva Germovsek
- Infectious Diseases and Microbiology Unit, University College London, Institute of Child Health, London WC1N 1EH, UK
| | - Rollo L Hoare
- Infectious Diseases and Microbiology Unit, University College London, Institute of Child Health, London WC1N 1EH, UK; CoMPLEX, University College London, Physics Building, Gower Street, London WC1E 6BT, UK
| | - Jodi M Lestner
- Paediatric Infectious Diseases Research Group, Division of Clinical Sciences, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK; Faculty of Medicine, Imperial College London, London, UK
| | - Joanna Lewis
- Infectious Diseases and Microbiology Unit, University College London, Institute of Child Health, London WC1N 1EH, UK; CoMPLEX, University College London, Physics Building, Gower Street, London WC1E 6BT, UK
| | - Joseph F Standing
- Infectious Diseases and Microbiology Unit, University College London, Institute of Child Health, London WC1N 1EH, UK; CoMPLEX, University College London, Physics Building, Gower Street, London WC1E 6BT, UK.
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De Cock RFW, Smits A, Allegaert K, de Hoon J, Saegeman V, Danhof M, Knibbe CAJ. Population pharmacokinetic modelling of total and unbound cefazolin plasma concentrations as a guide for dosing in preterm and term neonates. J Antimicrob Chemother 2014; 69:1330-8. [PMID: 24492261 DOI: 10.1093/jac/dkt527] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVES Cefazolin is frequently administered for antimicrobial prophylaxis and treatment of infections. In neonates, pharmacokinetic observations are limited and dosing regimens variable. The aim of this study was to describe the pharmacokinetics of cefazolin in neonates based on total and unbound concentrations to optimize cefazolin dosing. METHODS Thirty-six neonates [median birth body weight 2720 (range 540-4200) g, current body weight (cBW) 2755 (830-4200) g and postnatal age (PNA) 9 (1-30) days] receiving intravenous cefazolin (50 mg/kg/8 h) were included. Based on 119 total and unbound plasma concentrations, a population pharmacokinetic analysis with a covariate analysis was performed. Monte Carlo simulations were performed aiming for unbound concentrations above an MIC of 8 mg/L (>60% of the time) in all patients. RESULTS A one-compartment pharmacokinetic model was developed in which total and unbound concentrations were linked by maximum protein binding (Bmax) of 136 mg/L and a dissociation constant (KD) for cefazolin protein binding of 46.5 mg/L. cBW was identified as covariate for volume of distribution (V), bBW and PNA for clearance and albumin plasma concentration for Bmax, explaining 50%, 58% and 41% of inter-individual variability in V, clearance and Bmax, respectively. Based on Monte Carlo simulations, a body weight- and PNA-adapted dosing regimen that resulted in similar exposure across different weight and age groups was proposed. CONCLUSIONS A neonatal pharmacokinetic model taking into account total and unbound cefazolin concentrations with saturable plasma protein binding was identified. As cBW and PNA were the most important covariates, these may be used for individualized dosing in neonates.
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Affiliation(s)
- R F W De Cock
- Division of Pharmacology, LACDR, Leiden University, Leiden, The Netherlands
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Marsot A, Boulamery A, Bruguerolle B, Simon N. Population pharmacokinetic analysis during the first 2 years of life: an overview. Clin Pharmacokinet 2013. [PMID: 23179579 DOI: 10.1007/s40262-012-0015-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Three decades after its introduction, pharmacokinetic population approaches have become a reference method for drug modelling, particularly in paediatrics. The main practical limitation in this specific population is the collected blood volume. Pharmacokinetic population approaches using sparse sampling may resolve this issue. The pharmacokinetics of many drugs have been studied during the last 25 years using such methods. This review summarizes all of the published studies concerning population pharmacokinetic approaches in paediatric subjects from neonate to 2 years old. A literature search was conducted using the PubMed database, from 1985 to December 2010, using the following terms: pharmacokinetic(s), population, paediatric/pediatric and neonate(s). Articles were excluded if they were not pertinent according to our criteria. References of all relevant articles were also evaluated. Ninety-eight studies were included in this review. The following information was extracted from the articles: drug name, therapeutic class, population size, age of patients, number of samples per patient, covariates used for clearance and volume of distribution estimates, software used for modelling and validation methods. An increasing rate of publications over the years was observed; 44 different drugs were studied using a pharmacokinetic population approach. Antibacterials were the most studied class of drugs, including a large number of studies devoted to vancomycin and gentamicin. It must be underlined that few studies have been performed on anticonvulsant drugs and anaesthetics used in clinical daily practice conditions.
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Affiliation(s)
- Amélie Marsot
- Service de Pharmacologie Médicale et Clinique, Aix Marseille Université, France.
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Fleer A, Hemels MAC, Paauw A, Krediet TG. Reduced expression of PBP-2A by neonatal mecA-positive coagulase-negative staphylococci (CoNS) blood isolates: -lactams are useful first-line agents for the treatment of neonatal CoNS sepsis, restricting the use of vancomycin. J Antimicrob Chemother 2012; 67:1616-8. [DOI: 10.1093/jac/dks092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Pacifici GM. Clinical Pharmacokinetics of Penicillins, Cephalosporins and Aminoglycosides in the Neonate: A Review. Pharmaceuticals (Basel) 2010; 3:2568-2591. [PMID: 27713367 PMCID: PMC4033939 DOI: 10.3390/ph3082568] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 07/22/2010] [Accepted: 08/03/2010] [Indexed: 11/16/2022] Open
Abstract
Bacterial infections are common in the neonates and are a major cause of morbidity and mortality. Sixty percent of preterm infants admitted to neonatal intensive care units received at least one antibiotic during the first week of life. Penicillins, aminoglycosides and cephalosporins comprised 53, 43 and 16%, respectively. Kinetic parameters such as the half-life (t1/2), clearance (Cl), and volume of distribution (Vd) change with development, so the kinetics of penicillins, cephalosporins and aminoglycosides need to be studied in order to optimise therapy with these drugs. The aim of this study is to review the pharmacokinetics of penicillins, cephalosporins and aminoglycosides in the neonate in a single article in order to provide a critical analysis of the literature and thus provide a useful tool in the hands of physicians. The bibliographic search was performed electronically using PubMed, as the search engine, until February 2nd, 2010. Medline search terms were as follows: pharmacokinetics AND (penicillins OR cephalosporins OR aminoglycosides) AND infant, newborn, limiting to humans. Penicillins, cephalosporins and aminoglycosides are fairly water soluble and are mainly eliminated by the kidneys. The maturation of the kidneys governs the pharmacokinetics of penicillins, cephalosporins and aminoglycosides in the neonate. The renal excretory function is reduced in preterms compared to term infants and Cl of these drugs is reduced in premature infants. Gestational and postnatal ages are important factors in the maturation of the neonate and, as these ages proceed, Cl of penicillins, cephalosporins and aminoglycosides increases. Cl and t1/2 are influenced by development and this must be taken into consideration when planning a dosage regimen with these drugs. More pharmacokinetic studies are required to ensure that the dose recommended for the treatment of sepsis in the neonate is evidence based.
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Affiliation(s)
- Gian Maria Pacifici
- Section of Pharmacology, Department of Neurosciences, Medical School, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
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Pacifici GM, Labatia J, Mulla H, Choonara I. Clinical pharmacokinetics of penicillins in the neonate: a review of the literature. Eur J Clin Pharmacol 2008; 65:191-8. [DOI: 10.1007/s00228-008-0562-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Accepted: 08/26/2008] [Indexed: 11/30/2022]
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Pullen J, Stolk LML, Neef C, Zimmermann LJI. Microanalysis of amoxicillin, flucloxacillin, and rifampicin in neonatal plasma. Biomed Chromatogr 2008; 21:1259-65. [PMID: 17604357 DOI: 10.1002/bmc.881] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Simple and rapid reversed-phase high-performance liquid chromatographic assays with ultraviolet detection have been developed and validated for the determination of amoxicillin, flucloxacillin and rifampicin in neonatal plasma. Plasma samples were either precipitated with perchloric acid (amoxicillin) or methanol (rifampicin) or extracted with methylene chloride (flucloxacillin). Precision coefficients of variation and inaccuracy were less than 15% for all three assays. Only small sample volumes (20-40 microL) were required, making the assays suitable for therapeutic drug monitoring and pharmacokinetic studies in preterm and term neonates. The assays have successfully been applied to analysis of amoxicillin, flucloxacillin and rifampicin in previously published pharmacokinetic studies in neonates.
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Affiliation(s)
- J Pullen
- Department of Clinical Pharmacy and Toxicology of the University Hospital of Maastricht, Maastricht, The Netherlands.
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Rubino CM, Bradley JS. Optimizing therapy with antibacterial agents: use of pharmacokinetic-pharmacodynamic principles in pediatrics. Paediatr Drugs 2008; 9:361-9. [PMID: 18052406 DOI: 10.2165/00148581-200709060-00003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The appropriate dosage of antibacterial agents is essential in achieving both clinical and microbiologic success in the treatment of infections in children. By using in vitro experimental data and animal model outcome data, the pharmacokinetic-pharmacodynamic (PK-PD) parameters predictive of antibacterial effect have been elucidated. For time-dependent drugs such as beta-lactams, the PK-PD parameter of interest is the percentage of time in a dosage interval for which drug concentrations remain above the minimum inhibitory concentration (MIC) of the infecting organism. For concentration-dependent drugs such as aminoglycosides, the PK-PD parameter of interest is the ratio of the area under the plasma concentration-time curve to the MIC. Recent studies using data on clinical and microbiologic outcomes from infected adults and children, combined with data on drug exposure, have confirmed the importance of these parameters and provided estimates of the PK-PD goals of therapy for various antibacterial agents. Application of these PK-PD principles allows rational dosage regimen selection, both for serious infections in critically ill children and for non-life-threatening community-acquired infections.
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Affiliation(s)
- Christopher M Rubino
- Institute for Clinical Pharmacodynamics, Ordway Research Institute, Albany, NY 12206-1072, USA.
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Pullen J, Stolk LML, Degraeuwe PLJ, van Tiel FH, Neef C, Zimmermann LJI. Protein Binding of Flucloxacillin in Neonates. Ther Drug Monit 2007; 29:279-83. [PMID: 17529883 DOI: 10.1097/ftd.0b013e318063e30f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The isoxazolyl penicillins, including flucloxacillin, have the highest levels of plasma protein binding among the semisynthetic penicillins. Because only the free fraction of the penicillin is pharmacologically active, it would be useful to measure both protein-bound and free flucloxacillin to determine its protein binding. Until now, flucloxacillin protein binding in newborn infants has been investigated in only two studies with relatively small populations. In the present study, flucloxacillin protein binding was investigated in 56 (preterm) infants aged 3 to 87 days (gestational age, 25-41 weeks). Surplus plasma samples from routine gentamicin assays of each infant were collected and combined to obtain a sufficiently large sample for analysis. Free flucloxacillin was separated from protein-bound flucloxacillin using ultrafiltration. Reversed-phase high-performance liquid chromatography with ultraviolet detection was used to measure free flucloxacillin concentrations in ultrafiltrate and total flucloxacillin concentrations in pooled plasma. Flucloxacillin protein binding was 74.5% +/- 13.1% (mean +/- standard deviation) with a high variability among the infants (34.3% to 89.7%). High Pearson correlations were found between protein binding and the covariates-plasma albumin concentration (r = 0.804, P < 0.001, n = 18) and plasma creatinine concentration (r = -0.601, P < 0.001, n = 45). Statistically significant but less striking correlations were found between protein binding and gestational age, postconceptional age, body weight, and triglyceride concentration. Because of the high variability of protein binding among infants, it is difficult to devise a flucloxacillin dosage regimen effective for all infants. Individualized dosing, based on free flucloxacillin concentrations, might help to optimize treatment of late-onset neonatal sepsis, but practical obstacles will probably prevent analysis of free flucloxacillin concentrations in newborn infants on a routine basis.
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Affiliation(s)
- Joyce Pullen
- Department of Clinical Pharmacy and Toxicology, Division of Neonatology, University Hospital of Maastricht, Maastricht, The Netherlands.
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