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Hollander EM, van Tuinen EL, Schölvinck EH, Bergman KA, Bourgonje AR, Gracchi V, Kneyber MCJ, Touw DJ, Mian P. Evaluation of Dosing Guidelines for Gentamicin in Neonates and Children. Antibiotics (Basel) 2023; 12:antibiotics12050810. [PMID: 37237713 DOI: 10.3390/antibiotics12050810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/17/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023] Open
Abstract
Although aminoglycosides are frequently prescribed to neonates and children, the ability to reach effective and safe target concentrations with the currently used dosing regimens remains unclear. This study aims to evaluate the target attainment of the currently used dosing regimens for gentamicin in neonates and children. We conducted a retrospective single-center cohort study in neonates and children receiving gentamicin between January 2019 and July 2022, in the Beatrix Children's Hospital. The first gentamicin concentration used for therapeutic drug monitoring was collected for each patient, in conjunction with information on dosing and clinical status. Target trough concentrations were ≤1 mg/L for neonates and ≤0.5 mg/L for children. Target peak concentrations were 8-12 mg/L for neonates and 15-20 mg/L for children. In total, 658 patients were included (335 neonates and 323 children). Trough concentrations were outside the target range in 46.2% and 9.9% of neonates and children, respectively. Peak concentrations were outside the target range in 46.0% and 68.7% of neonates and children, respectively. In children, higher creatinine concentrations were associated with higher gentamicin trough concentrations. This study corroborates earlier observational studies showing that, with a standard dose, drug concentration targets were met in only approximately 50% of the cases. Our findings show that additional parameters are needed to improve target attainment.
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Affiliation(s)
- Esther M Hollander
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Eline L van Tuinen
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Elisabeth H Schölvinck
- Department of Pediatric Infectious Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Klasien A Bergman
- Division of Neonatology, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Arno R Bourgonje
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
| | - Valentina Gracchi
- Division of Pediatric Nephrology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Martin C J Kneyber
- Division of Peadiatric Critical Care Medicine, Department of Paediatrics, Beatrix Children's Hospital Groningen, University Medical Center Groningen, University of Groningen Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Daan J Touw
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
- Department of Pharmaceutical Analysis, Groningen Research Institute for Pharmacy, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Paola Mian
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
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Gentamicin Dosing in Neonates with Normal Renal Function: Trough and Peak Levels. Eur J Drug Metab Pharmacokinet 2021; 46:677-684. [PMID: 34370216 DOI: 10.1007/s13318-021-00708-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND AND OBJECTIVE: Gentamicin is commonly used in neonates, and it requires drug concentration monitoring. The objective of this study was to determine the extent of high trough (≥ 2 mg/l) and therapeutic peak serum gentamicin concentrations (5-12 mg/l) using our current gentamicin regimen and to adjust the dosing regimen accordingly and reassess. METHODS This was a prospective cohort study of neonates, with normal renal function, who were prescribed gentamicin. Group 1: March 2014-July 2017-gentamicin intravenous (IV) 2.5 mg/kg given every 36 h if < 30 weeks gestational age (GA) and every 24 h if ≥ 30 weeks GA; Group 2: August 2019-February 2020-gentamicin IV 3.5 mg/kg given every 36 h if < 30 weeks GA and every 24 h if ≥ 30 weeks GA. We assessed the number of neonates with aberrant trough and peak serum gentamicin concentrations. RESULTS Forty-eight neonates < 30 weeks GA and 34 ≥ 30 weeks GA were given 2.5 mg/kg gentamicin. Eleven (23%) neonates < 30 weeks GA and four (13%) ≥ 30 weeks GA had subtherapeutic peak concentrations (< 5 mg/l); none had supratherapeutic (> 12 mg/l) or toxic trough concentrations (≥ 2 mg/l). Forty-four neonates < 30 weeks GA and 54 ≥ 30 weeks GA were given 3.5 mg/kg gentamicin. Eighty-four (86%) had non-toxic trough concentrations (< 2 mg/l). One (1%) < 30 weeks GA neonate had subtherapeutic (< 5 mg/l) and one (1%) neonate ≥ 30 weeks GA had supratherapeutic (> 12 mg/l) peak concentrations. CONCLUSIONS Gentamicin regimen of 2.5 mg/kg given every 36 h for neonates < 30 weeks GA and every 24 h for neonates ≥ 30 weeks GA was suboptimal at achieving therapeutic gentamicin peak. Increasing the dosage to 3.5 mg/kg achieved therapeutic peak concentrations in 98% and non-toxic trough concentrations in 86% of all neonates (prior to dose interval adjustment).
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Neeli H, Hanna N, Abduljalil K, Cusumano J, Taft DR. Application of Physiologically Based Pharmacokinetic-Pharmacodynamic Modeling in Preterm Neonates to Guide Gentamicin Dosing Decisions and Predict Antibacterial Effect. J Clin Pharmacol 2021; 61:1356-1365. [PMID: 33945155 DOI: 10.1002/jcph.1890] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 04/24/2021] [Indexed: 01/22/2023]
Abstract
Clinical studies in preterm neonates are rarely performed due to ethical concerns and difficulties associated with trials and recruitment. Consequently, dose selection in this population is primarily empirical. Scaling neonatal doses from adult doses does not account for developmental changes and may not accurately predict drug kinetics. This is especially important for gentamicin, a narrow therapeutic index aminoglycoside antibiotic. While gentamicin's bactericidal effect is associated with its peak plasma concentration, keeping trough concentrations below 1 µg/mL prevents toxicity and also helps to counteract adaptive resistance in bacteria such as Escherichia coli. In this study, physiologically based pharmacokinetic-pharmacodynamic (PBPK-PD) modeling was used to support and/or guide dosing decisions and to predict the antibacterial effect in preterm neonates. A gentamicin PBPK model was successfully verified in healthy adults and preterm neonates across all gestational ages. Clinical data from a neonatal intensive care unit at NYU Langone Hospital-Long Island was used to identify dosing regimens associated with increased incidence of elevated gentamicin trough concentrations in different preterm patient cohorts. Model predictions demonstrated that a higher dose with an extended-dosing interval (every 36 hours) in neonates with a postmenstrual age of 30 to 34 weeks and ≥35 weeks, with postnatal age 8 to 28 days and 0 to 7 days, respectively, were more likely to have a trough <1 µg/mL when compared with once-daily (every 24 hours) dosing. PBPK-PD modeling suggested that a higher dose administered every 36 hours may provide effective antibacterial therapy.
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Affiliation(s)
- Harshith Neeli
- Samuel J. and Joan B. Williamson Institute for Pharmacometrics, Division of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, New York, USA
| | - Nazeeh Hanna
- Division of Neonatology, NYU Langone Hospital-Long Island, Mineola, New York, USA
| | | | - Jaclyn Cusumano
- Division of Pharmacy Practice, Arnold and Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, New York, USA
| | - David R Taft
- Samuel J. and Joan B. Williamson Institute for Pharmacometrics, Division of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, New York, USA
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Le J, Greenberg RG, Benjamin DK, Yoo Y, Zimmerman KO, Cohen-Wolkowiez M, Wade KC. Prolonged Post-Discontinuation Antibiotic Exposure in Very Low Birth Weight Neonates at Risk for Early-Onset Sepsis. J Pediatric Infect Dis Soc 2021; 10:615-621. [PMID: 33491088 PMCID: PMC8163059 DOI: 10.1093/jpids/piaa172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/28/2020] [Indexed: 11/13/2022]
Abstract
BACKGROUND Premature, very low birth weight (VLBW) neonates are at risk for early-onset sepsis and receive ampicillin and gentamicin post-birth. Antimicrobial stewardship supports short-course antibiotics, but how long antibiotic concentrations remain therapeutic post-last dose is unknown. METHODS Using Monte Carlo simulations (NONMEM 7.3), we analyzed antibiotic exposures in a retrospective cohort of 34 689 neonates (<1500 g, 22-27 weeks of gestation). Therapeutic exposure for ampicillin and gentamicin was evaluated relative to the minimum inhibitory concentration (MIC) for common pathogens (MIC 0.25-8 mcg/mL for group B streptococcus [GBS] and Escherichia coli). Post-discontinuation antibiotic exposure (PDAE) was defined as the time from the last dose to time when concentration decreased below MIC. RESULTS Neonates had a median (range) gestational age of 26 (22-27) weeks and BW, 790 g (400-1497) . All ampicillin dosing regimens (50-100 mg/kg every 8-12 hours for 2-6 doses) achieved therapeutic exposures > MIC range. After the last dose, the PDAE mean (95% confidence interval [CI]) ranged from 34 to 50 hours (17-79) for E. coli (MIC 8) and 82 to 104 hours (95% CI: 39-122) for GBS (MIC 0.25); longer PDAE occurred with higher dose, shorter interval, and longer course. Short-course ampicillin (2 doses, 50 mg/kg every 12 hours) provided PDAE 34 hours for E. coli and 82 hours for GBS. Single-dose 5 mg/kg gentamicin provided PDAE > MIC 2 for 26 hours. CONCLUSIONS In VLBW neonates, ampicillin exposure remains therapeutic long after the last dose. Short-course ampicillin provided therapeutic exposures throughout the typical blood culture incubation period.
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Affiliation(s)
- Jennifer Le
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California–San Diego, La Jolla, California, USA
| | - Rachel G Greenberg
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
- Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Daniel K Benjamin
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
- Duke Clinical Research Institute, Durham, North Carolina, USA
| | - YoungJun Yoo
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California–San Diego, La Jolla, California, USA
| | - Kanecia O Zimmerman
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
- Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Michael Cohen-Wolkowiez
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
- Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Kelly C Wade
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
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Sridharan K, Al Jufairi M, Qader AM, Elsegai OAM. Dose Optimization of Gentamicin in Critically Ill Neonates. Curr Drug Metab 2021; 21:270-280. [PMID: 32394828 DOI: 10.2174/1389200221666200512111131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/11/2020] [Accepted: 04/09/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Appropriate dosing of gentamicin in critically ill neonates is still debated. OBJECTIVE To assess the peak concentration (Cmax) and area-under-the-time-concentration curve (AUC0-24) of gentamicin and to simulate the recommended doses using the Monte Carlo method. METHODS This was a retrospective study on critically ill neonates carried over a one-year period. The demographic characteristics, dosage regimen and gentamicin concentrations were recorded for each neonate. Using Bayesian pharmacokinetic modeling, Cmax and AUC0-24 were predicted. Dose recommendations for the target Cmax (μg/ml) of 12 were obtained, and Monte Carlo simulation (100,000 iterations) was used for predicting the pharmacokinetic parameters and recommended doses for various birth weight categories. RESULTS Eighty-two critically ill neonates (with an average gestational age of 33.7 weeks; and birth weight of 2.1 kg) were recruited. Higher Cmax and AUC0-24 values were predicted in premature neonates, with greater cumulative AUCs in extremely preterm neonates. The average administered dose was 4 mg/kg/day and 75% of the participants had Cmax greater than 12 μg/ml following a single dose, and 85% were found to be at steady state. On the contrary, only 25% of the study population had the recommended AUC0-24 (above 125 μg-hr/ml). Simulation tests indicate that 90% of the critically ill neonates would achieve recommended Cmax with doses ranging between 5 and 6 mg/kg/day. CONCLUSION Currently used dose of 4 mg/kg/day is adequate to maintain Cmax in a large majority of the study population, with one-fourth population reporting the recommended AUC0-24. Increasing the dose to 5-6 mg/kg/day will more likely help to achieve both the recommended Cmax and AUC0-24 values.
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Affiliation(s)
- Kannan Sridharan
- Department of Pharmacology & Therapeutics, College of Medicine & Medical Sciences, Arabian Gulf University, Manama, Bahrain
| | - Muna Al Jufairi
- Department of Pediatrics, College of Medicine & Medical Sciences, Arabian Gulf University, Manama, Bahrain.,Neonatal Intensive Care Unit, Salmaniya Medical Hospital, Ministry of Health, Manama, Bahrain
| | - Ali Mohamed Qader
- College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain
| | - Ola A M Elsegai
- Department of Pathology-Biochemistry, Salmaniya Medical Hospital, Ministry of Health, Manama, Bahrain
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Crcek M, Zdovc J, Kerec Kos M. A review of population pharmacokinetic models of gentamicin in paediatric patients. J Clin Pharm Ther 2019; 44:659-674. [PMID: 31102287 DOI: 10.1111/jcpt.12850] [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] [Received: 10/05/2018] [Revised: 03/18/2019] [Accepted: 04/24/2019] [Indexed: 11/28/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVES Gentamicin is often used for the treatment of Gram-negative infections. Due to pharmacokinetic variability in paediatric patients, appropriate dosing of gentamicin in the paediatric population is challenging. This article reviews published population pharmacokinetic models of gentamicin in paediatric patients, identifies covariates that significantly influence gentamicin pharmacokinetics, and determines whether there is a consensus on proposed dosing for intravenous gentamicin in this population. METHODS The PubMed database was searched for articles published until the end of 2017. If the articles described population pharmacokinetic models of gentamicin in the paediatric population (after intravenous administration of gentamicin), the following data were extracted: type of study, year of publication, population characteristics and number of patients, gentamicin dosing, total number of gentamicin (serum and/or plasma) concentrations, type of population modelling approach, developed model with pharmacokinetic parameters and covariates included. RESULTS AND DISCUSSION In most of the studies, one- or two-compartment modelling was applied. The mean estimated gentamicin clearance for newborns, infants and the complete paediatric population was 0.048, 0.13 and 0.067 L/h/kg, respectively, and the mean predicted volume of distribution was 0.475, 0.35 and 0.33 L/kg, respectively. The values reflect differences in body composition and kidney maturation within the different paediatric populations. Gentamicin pharmacokinetics were most influenced by age, body size and renal function. WHAT IS NEW AND CONCLUSION Based on our review, the authors agree on a prolonged dosing interval for preterm and term newborns (up to 48 hours). However, there was no agreement on proposed dosing with respect to gestational age. In general, the proposed daily doses were lower compared to those initially applied for preterm newborns and comparable to those for term newborns. For infants and children, the dosing interval remained unchanged (24 hours), but the proposed daily doses were higher than actually applied. When differences in the paediatric population are considered and an appropriate population PK model with applicable covariates is applied, dosing can be individualized. In the future, studies of gentamicin pharmacokinetics in paediatric patients should focus on currently underestimated covariates, such as fat-free mass, concomitantly administered drugs, body temperature and critical illness because these can change gentamicin PK considerably. Consequently, different dosing is required and TDM becomes even more important.
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Affiliation(s)
- Mateja Crcek
- University of Ljubljana, Faculty of Pharmacy, Department of Biopharmaceutics and Pharmacokinetics, Ljubljana, Slovenia
| | - Jurij Zdovc
- University of Ljubljana, Faculty of Pharmacy, Department of Biopharmaceutics and Pharmacokinetics, Ljubljana, Slovenia
| | - Mojca Kerec Kos
- University of Ljubljana, Faculty of Pharmacy, Department of Biopharmaceutics and Pharmacokinetics, Ljubljana, Slovenia
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Cies JJ, Habib T, Bains V, Young M, Menkiti OR. Population Pharmacokinetics of Gentamicin in Neonates with Hypoxemic-Ischemic Encephalopathy Receiving Controlled Hypothermia. Pharmacotherapy 2018; 38:1120-1129. [PMID: 30300445 DOI: 10.1002/phar.2186] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Identify population pharmacokinetics and pharmacodynamic target attainment of gentamicin in neonates with hypoxic-ischemic encephalopathy (HIE) undergoing controlled hypothermia (CH). DESIGN Prospective open-label pharmacokinetic study. Gentamicin concentrations were modeled and dosing regimens simulated for a 5000-patient neonatal population with HIE receiving CH using PMetrics, a nonparametric, pharmacometric modeling, and simulation package for R. SETTING A 189-bed children's tertiary care teaching hospital. RESULTS Twelve patients, 5 (42%) females and 7 (58%) males, met inclusion criteria with a median gestation age of 39.9 weeks (interquartile range [IQR] 38.5-40.2 wks) and a median birthweight (BW) of 3.3 kg (IQR 3.1-3.7 kg). Gentamicin concentrations were best described by a two-compartment model with first-order elimination with BW as a covariate on volume of distribution (Vd). The mean total body population clearance (CL) was 2.2 ± 0.7 ml/minute/kg, and the volume of the central compartment was 0.44 ± 0.06 L/kg. The R2 , bias, and precision for the observed versus population predicted model were 0.917, 1.15, and 10.9 μg/ml; the R2 , bias, and precision for the observed versus individual predicted model were 0.982, -0.132, and 0.932 μg/ml, respectively. The calculated mean population estimate for the total Vd was 0.96 ± 0.4 L/kg. The dosing regimen that most consistently produced a maximum concentration (Cmax ) in the range of 10-12 mg/L with a minimum concentration (Cmin ) level less than 2 mg/L was 5 mg/kg/dose given every 36 hours. CONCLUSION These data suggest the population pharmacokinetics of gentamicin in neonates with HIE receiving CH have an increase in gentamicin CL and are different from previous reports in neonates with HIE not receiving CH and/or neonates without HIE. This analysis suggests a dosing regimen of 5 mg/kg/dose every 36 hours results in a gentamicin Cmax within the range of 10-12 mg/L with a Cmin lower than 2 mg/L, which is appropriate for treating susceptible gram-negative organisms with minimum inhibitory concentrations of 1 mg/L or lower.
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Affiliation(s)
- Jeffrey J Cies
- The Center for Pediatric Pharmacotherapy, LLC, Pottstown, Pennsylvania.,St. Christopher's Hospital for Children, Philadelphia, Pennsylvania.,Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Thomas Habib
- St. Christopher's Hospital for Children, Philadelphia, Pennsylvania.,Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Vidhy Bains
- St. Christopher's Hospital for Children, Philadelphia, Pennsylvania
| | - Megan Young
- St. Christopher's Hospital for Children, Philadelphia, Pennsylvania
| | - Ogechukwu R Menkiti
- St. Christopher's Hospital for Children, Philadelphia, Pennsylvania.,Drexel University College of Medicine, Philadelphia, Pennsylvania
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van Donge T, Pfister M, Bielicki J, Csajka C, Rodieux F, van den Anker J, Fuchs A. Quantitative Analysis of Gentamicin Exposure in Neonates and Infants Calls into Question Its Current Dosing Recommendations. Antimicrob Agents Chemother 2018; 62:e02004-17. [PMID: 29358294 PMCID: PMC5913996 DOI: 10.1128/aac.02004-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/09/2018] [Indexed: 12/20/2022] Open
Abstract
Optimal dosing of gentamicin in neonates is still a matter of debate despite its common use. We identified gentamicin dosing regimens from eight international guidelines and seven Swiss neonatal intensive care units. The dose per administration, the dosing interval, the total daily dose, and the demographic characteristics between guidelines were compared. There was considerable variability with respect to dose (4 to 6 mg/kg), dosing interval (24 h to 48 h), total daily dose (2.5 to 6 mg/kg/day), and patient demographic characteristics that were used to calculate individualized dosing regimens. A model-based simulation study in 1071 neonates was performed to determine the achievement of efficacious peak gentamicin concentrations according to predefined MICs (Cmax/MIC ≥ 10) and safe trough concentrations (Cmin ≤ 2 mg/liter) with recommended dosing regimens. MIC targets of 0.5 and 1 mg/liter were used. Dosing optimization was performed giving priority to the first day of treatment and with the goal of simplifying dosing. Current gentamicin neonatal guidelines allow to achieve effective peak concentrations for MICs ≤ 0.5 mg/liter but not higher. Model-based simulations indicate that to attain peak gentamicin concentrations of ≥10 mg/liter, a dose of 7.5 mg/kg should be administered using an extended dosing interval regimen. Trough concentrations of ≤2 mg/liter can be maintained with a dosing interval of 36 to 48 h in neonates according to gestational and postnatal age. For treatment beyond 3 days, therapeutic drug monitoring is advised to maintain adequate serum concentrations.
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Affiliation(s)
- Tamara van Donge
- Paediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital, Basel, Switzerland
| | - Marc Pfister
- Paediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital, Basel, Switzerland
- Quantitative Solutions, a Certara Company, London, United Kingdom
| | - Julia Bielicki
- Paediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital, Basel, Switzerland
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, London, United Kingdom
| | - Chantal Csajka
- Service of Clinical Pharmacology, Department of Laboratory, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Frederique Rodieux
- Service of Clinical Pharmacology and Toxicology, Geneva University Hospitals, Geneva, Switzerland
| | - John van den Anker
- Paediatric Pharmacology and Pharmacometrics Research, 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
| | - Aline Fuchs
- Paediatric Pharmacology and Pharmacometrics Research, University of Basel Children's Hospital, Basel, Switzerland
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Antolik TL, Cunningham KJ, Alabsi S, Reimer RA. Empirical gentamicin dosing based on serum creatinine levels in premature and term neonates. Am J Health Syst Pharm 2017; 74:466-472. [DOI: 10.2146/ajhp160061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Taylar L. Antolik
- Iowa Methodist Medical Center, UnityPoint Health Des Moines, Des Moines, IA
| | | | - Samir Alabsi
- Blank Children’s Hospital, UnityPoint Health Des Moines, Des Moines, IA
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Aonuma K, Shiga T, Atarashi H, Doki K, Echizen H, Hagiwara N, Hasegawa J, Hayashi H, Hirao K, Ichida F, Ikeda T, Maeda Y, Matsumoto N, Sakaeda T, Shimizu W, Sugawara M, Totsuka K, Tsuchishita Y, Ueno K, Watanabe E, Hashiguchi M, Hirata S, Kasai H, Matsumoto Y, Nogami A, Sekiguchi Y, Shinohara T, Sugiyama A, Sumitomo N, Suzuki A, Takahashi N, Yukawa E, Homma M, Horie M, Inoue H, Ito H, Miura T, Ohe T, Shinozaki K, Tanaka K. Guidelines for Therapeutic Drug Monitoring of Cardiovascular Drugs Clinical Use of Blood Drug Concentration Monitoring (JCS 2015) ― Digest Version ―. Circ J 2017; 81:581-612. [DOI: 10.1253/circj.cj-66-0138] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Should gentamicin trough levels be routinely obtained in term neonates? J Perinatol 2016; 36:962-965. [PMID: 27537855 DOI: 10.1038/jp.2016.120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/13/2016] [Accepted: 06/27/2016] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Gentamicin is a common antibiotic used to treat sepsis in neonates. We hypothesize that obtaining routine gentamicin trough levels may not be necessary in low-risk, term infants. STUDY DESIGN We performed a retrospective cohort study of term infants (n=346) treated with gentamicin in a single level III neonatal intensive care unit (NICU). The results of gentamicin trough levels and the correlation with risk factors and potential side effects were recorded. In addition, we conducted a survey of 75 academic NICUs across the United States regarding their gentamicin monitoring practice. RESULTS Routine trough levels did not predict potential gentamicin toxicity in neonates with low risk factors. Regression analysis demonstrated a positive correlation between gentamicin trough levels and serum creatinine. The survey of the NICUs in the United States demonstrated significant inconsistency in gentamicin monitoring practice. CONCLUSION Obtaining gentamicin trough levels guided by risk factors is more appropriate than obtaining routine trough levels in low-risk term neonates.
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13
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Bijleveld YA, de Haan TR, van der Lee HJH, Groenendaal F, Dijk PH, van Heijst A, de Jonge RCJ, Dijkman KP, van Straaten HLM, Rijken M, Zonnenberg IA, Cools F, Zecic A, Nuytemans DHGM, van Kaam AH, Mathot RAA. Altered gentamicin pharmacokinetics in term neonates undergoing controlled hypothermia. Br J Clin Pharmacol 2016; 81:1067-77. [PMID: 26763684 PMCID: PMC4876193 DOI: 10.1111/bcp.12883] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 01/05/2016] [Accepted: 01/10/2016] [Indexed: 11/29/2022] Open
Abstract
AIM(S) Little is known about the pharmacokinetic (PK) properties of gentamicin in newborns undergoing controlled hypothermia after suffering from hypoxic−ischaemic encephalopathy due to perinatal asphyxia. This study prospectively evaluates and describes the population PK of gentamicin in these patients METHODS Demographic, clinical and laboratory data of patients included in a multicentre prospective observational cohort study (the ‘PharmaCool Study’) were collected. A non-linear mixed-effects regression analysis (nonmem®) was performed to describe the population PK of gentamicin. The most optimal dosing regimen was evaluated based on simulations of the final model. RESULTS A total of 47 patients receiving gentamicin were included in the analysis. The PK were best described by an allometric two compartment model with gestational age (GA) as a covariate on clearance (CL). During hypothermia the CL of a typical patient (3 kg, GA 40 weeks, 2 days post-natal age (PNA)) was 0.06 l kg−1 h−1 (inter-individual variability (IIV) 26.6%) and volume of distribution of the central compartment (Vc) was 0.46 l kg−1 (IIV 40.8%). CL was constant during hypothermia and rewarming, but increased by 29% after reaching normothermia (>96 h PNA). CONCLUSIONS This study describes the PK of gentamicin in neonates undergoing controlled hypothermia. The 29% higher CL in the normothermic phase compared with the preceding phases suggests a delay in normalization of CL after rewarming has occurred. Based on simulations we recommend an empiric dose of 5 mg kg−1 every 36 h or every 24 h for patients with GA 36–40 weeks and GA 42 weeks, respectively.
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Affiliation(s)
| | - Timo R de Haan
- Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam
| | - Hanneke J H van der Lee
- Pediatric Clinical Research Office, Division Woman-Child, Academic Medical Center, University of Amsterdam, Amsterdam
| | - Floris Groenendaal
- Department of Neonatology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht
| | - Peter H Dijk
- Department of Neonatology, University Medical Center Groningen, Groningen
| | - Arno van Heijst
- Department of Neonatology, Radboud University Medical Center, Nijmegen
| | - Rogier C J de Jonge
- Department of Pediatrics, Division of Neonatology, Erasmus MC-Sophia Children's Hospital, Rotterdam
| | - Koen P Dijkman
- Department of Neonatology, Máxima Medical Center Veldhoven, Veldhoven
| | | | - Monique Rijken
- Department of Neonatology, Leiden University Medical Center, Leiden
| | - Inge A Zonnenberg
- Department of Neonatology, VU University Medical Center, Amsterdam, The Netherlands
| | - Filip Cools
- Department of Neonatology, Vrije Universiteit Brussel, Brussels
| | - Alexandra Zecic
- Department of Neonatology, Academic Medical Center, Gent, Belgium
| | | | - Anton H van Kaam
- Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam
| | - Ron A A Mathot
- Department of Pharmacy, Academic Medical Center, Amsterdam
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14
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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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15
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Grimsrud KN, Sherwin CMT, Constance JE, Tak C, Zuppa AF, Spigarelli MG, Mihalopoulos NL. Special population considerations and regulatory affairs for clinical research. CLINICAL RESEARCH AND REGULATORY AFFAIRS 2015; 32:47-56. [PMID: 26401094 PMCID: PMC4577021 DOI: 10.3109/10601333.2015.1001900] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Special populations, including women (non-pregnant and pregnant), pediatrics, and the elderly, require additional consideration with regard to clinical research. There are very specific regulatory laws, which protect these special populations, that need to be understood and adhered to in order to perform clinical research. This review provides a broad overview of some of the physiological differences in special populations and discusses how these differences may affect study design and regulatory considerations. These various special populations, with respect to regulatory affairs, are clearly defined within the Code of Federal Regulations. The definition of "special population" exists to provide enhanced awareness of their vulnerabilities, thereby allowing the creation of regulatory guidance aimed to decrease injury or outright harm. Currently, progress is being made to be more inclusive of special populations in clinical trials. This reflects changing attitudes towards drug information, with it being more representative of those patients that will ultimately be prescribed or exposed to the therapy. However, all research undertaken in these populations should be performed in a manner that ensures all protections of each participant are upheld.
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Affiliation(s)
- Kristin N. Grimsrud
- Department of Surgery, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Catherine M. T. Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jonathan E. Constance
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Casey Tak
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Athena F. Zuppa
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, PA, USA
| | - Michael G. Spigarelli
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
- Division of Adolescent Medicine, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nicole L. Mihalopoulos
- Division of Adolescent Medicine, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
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16
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Fuchs A, Guidi M, Giannoni E, Werner D, Buclin T, Widmer N, Csajka C. Population pharmacokinetic study of gentamicin in a large cohort of premature and term neonates. Br J Clin Pharmacol 2015; 78:1090-101. [PMID: 24938850 DOI: 10.1111/bcp.12444] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 06/09/2014] [Indexed: 12/01/2022] Open
Abstract
AIM This study aims to investigate the clinical and demographic factors influencing gentamicin pharmacokinetics in a large cohort of unselected premature and term newborns and to evaluate optimal regimens in this population. METHODS All gentamicin concentration data, along with clinical and demographic characteristics, were retrieved from medical charts in a Neonatal Intensive Care Unit over 5 years within the frame of a routine therapeutic drug monitoring programme. Data were described using non-linear mixed-effects regression analysis ( nonmem®). RESULTS A total of 3039 gentamicin concentrations collected in 994 preterm and 455 term newborns were included in the analysis. A two compartment model best characterized gentamicin disposition. The average parameter estimates, for a median body weight of 2170 g, were clearance (CL) 0.089 l h(-1) (CV 28%), central volume of distribution (Vc ) 0.908 l (CV 18%), intercompartmental clearance (Q) 0.157 l h(-1) and peripheral volume of distribution (Vp ) 0.560 l. Body weight, gestational age and post-natal age positively influenced CL. Dopamine co-administration had a significant negative effect on CL, whereas the influence of indomethacin and furosemide was not significant. Both body weight and gestational age significantly influenced Vc . Model-based simulations confirmed that, compared with term neonates, preterm infants need higher doses, superior to 4 mg kg(-1) , at extended intervals to achieve adequate concentrations. CONCLUSIONS This observational study conducted in a large cohort of newborns confirms the importance of body weight and gestational age for dosage adjustment. The model will serve to set up dosing recommendations and elaborate a Bayesian tool for dosage individualization based on concentration monitoring.
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Affiliation(s)
- Aline Fuchs
- Division of Clinical Pharmacology, Service of Biomedicine, Department of Laboratory, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
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17
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Impact of clinical decision support guidelines on therapeutic drug monitoring of gentamicin in newborns. Ther Drug Monit 2015; 36:656-62. [PMID: 24690586 DOI: 10.1097/ftd.0000000000000071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Our institution's gentamicin dosing and therapeutic drug monitoring (TDM) practices for newborns were suspected to be very heterogeneous. Once-daily dosing (ODD) or extended-interval dosing (EID) and trough concentration measurement were recommended. Clinical decision support guidelines were developed and implemented as clinical decision support in the computerized prescriber order entry system. Impact on dosing, TDM practices, and blood sampling were evaluated. METHODS A 1-year retrospective historically controlled study before (April 2008-March 2009) and after the implementation of guidelines (January 2010-December 2010) for newborns (<30 days of life) receiving gentamicin. Blood concentrations (% of peak concentrations sampled, % of patients with zero or one concentration sampled, % of trough concentrations ≤1 mg/L) and dose regimen (ODD/EID) were compared between groups. Factors potentially associated with gentamicin concentration were analyzed (multivariate analysis). RESULTS One hundred thirty-two (postguidelines) versus 102 (preguidelines) patients were included (median gestational age: 34.3 versus 35.8 weeks, P > 0.05). After implementation of the guidelines, an ODD/EID regimen was almost exclusively used (97.7% versus 61.6%, P < 0.001), the percentage of peak concentrations (0.9% versus 17.2%, P < 0.001) and the number of blood samples per patient (87.1% having 0 or 1 concentration measured versus 48.0, P < 0.001) sharply reduced. A significantly higher percentage of trough concentrations were ≤1 mg/L (68.5% versus 33.0%, P < 0.001). The probability of a trough concentration ≤1 mg/L increased with an ODD/EID regimen (odds ratio, 7.23; 95% confidence interval: 3.48-15.0, P < 0.001) and in the postguidelines group (odds ratio, 2.02; 95% confidence interval: 1.01-4.02, P = 0.045). CONCLUSIONS Guideline implementation generated a sharp reduction in blood sampling. Clinical benefits of better gentamicin dosing and TDM practices were evident. Cost-effectiveness and clinical benefit of reduced blood sampling should be evaluated.
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18
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Roberts JK, Stockmann C, Constance JE, Stiers J, Spigarelli MG, Ward RM, Sherwin CMT. Pharmacokinetics and Pharmacodynamics of Antibacterials, Antifungals, and Antivirals Used Most Frequently in Neonates and Infants. Clin Pharmacokinet 2014; 53:581-610. [DOI: 10.1007/s40262-014-0147-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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19
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Fjalstad JW, Laukli E, van den Anker JN, Klingenberg C. High-dose gentamicin in newborn infants: is it safe? Eur J Pediatr 2013; 173:489-495. [PMID: 24233331 DOI: 10.1007/s00431-013-2194-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 10/21/2013] [Indexed: 12/17/2022]
Abstract
Dosing regimens often recommend lower gentamicin doses in neonates (3-5 mg/kg) than in older children (7 mg/kg or more) despite the higher volume of distribution in neonates. We studied an extended-interval high-dose (6 mg/kg) gentamicin regimen in a single tertiary neonatal unit from 2004-2012. During the first week of life, dosing interval was 24 h for term infants, 36 h for preterm infants with gestational age (GA) 29-36 weeks and 48 h for preterm infants with GA <29 weeks. After the first week of life, dosing interval was 24 h if corrected age (GA + postnatal age) ≥29 weeks and 36 h if corrected age <29 weeks. Outcome measures were trough plasma concentration (TPC), ototoxicity and prescription errors. In 546 treatment episodes, TPC was measured prior to the third gentamicin dose. There were 37 episodes (6.7 %) of prescription errors, mainly a too long dosing interval. We included 509 treatment episodes (440 infants) in the final analysis. Mean (standard deviation) gentamicin TPC during the first week of life was 1.1 (0.5) mg/L and after the first week of life 0.8 (0.6) mg/L. In 31 (6 %) episodes, TPC was ≥2.0 mg/L, predominantly among term infants with renal impairment. Thirty-eight patients failed the neonatal hearing screening, but only four of these 38 had permanent hearing loss. All four had a TPC <2.0 mg/L. Conclusions: This extended-interval high-dose gentamicin regimen was associated with low numbers of elevated TPCs, low numbers of prescription errors and no evidence for ototoxicity.
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Affiliation(s)
- Jon Widding Fjalstad
- Paediatric Research Group, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
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20
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Lulic-Botica M, Sheer T, Edwards D, Thomas RL, Natarajan G. Impact of small-for-gestational age (SGA) status on gentamicin pharmacokinetics in neonates. J Clin Pharmacol 2013; 54:39-45. [DOI: 10.1002/jcph.190] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 09/17/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Mirjana Lulic-Botica
- Department of Pharmacy; Hutzel Women's Hospital; Detroit MI USA
- Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences; Wayne State University; Detroit MI USA
| | - Terri Sheer
- Department of Pharmacy; Hutzel Women's Hospital; Detroit MI USA
| | - David Edwards
- Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences; Wayne State University; Detroit MI USA
| | - Ronald L. Thomas
- Division of Biostatistics; Children's Hospital of Michigan; Detroit MI USA
| | - Girija Natarajan
- Division of Neonatology; Children's Hospital of Michigan; Wayne State University; Detroit MI USA
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21
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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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22
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Frymoyer A, Meng L, Bonifacio SL, Verotta D, Guglielmo BJ. Gentamicin pharmacokinetics and dosing in neonates with hypoxic ischemic encephalopathy receiving hypothermia. Pharmacotherapy 2013; 33:718-26. [PMID: 23553582 DOI: 10.1002/phar.1263] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
STUDY OBJECTIVE To evaluate the pharmacokinetics of gentamicin in neonates with hypoxic ischemic encephalopathy (HIE) receiving hypothermia and to identify an empiric gentamicin dosing strategy in this population that optimizes achievement of target peak and trough concentrations. DESIGN Population pharmacokinetic study using retrospective medical record data. SETTING Tertiary neonatal intensive care unit. PATIENTS A total of 29 full-term neonates diagnosed with HIE treated with hypothermia who received gentamicin and underwent therapeutic drug monitoring MEASUREMENT AND MAIN RESULTS Patient demographics and gentamicin concentration data were retrospectively collected over a 2-year period. A population-based pharmacokinetic model was developed using nonlinear mixed-effects modeling (NONMEM). Using the developed model, Monte Carlo simulations were performed to evaluate the probability of achieving target peak (> 6 mg/L) and trough (< 2 mg/L) gentamicin concentrations for various potential dosing regimens. A one-compartment model best described the available gentamicin concentration data. Birthweight and serum creatinine significantly influenced gentamicin clearance. For the typical study neonate (birthweight 3.3 kg, serum creatinine 0.9 mg/dl), clearance was 0.034 L/hour/kg and volume was 0.52 L/kg. At a 24-hour dosing interval, Monte Carlo simulations predicted target gentamicin peak and trough concentrations could not be reliably achieved at any dose. At a 36-hour dosing interval, a dose of 4-5 mg/kg is predicted to achieve target gentamicin peak and trough concentrations in more than 90% of neonates. CONCLUSIONS Gentamicin clearance is decreased in neonates with HIE treated with hypothermia compared with previous reports in nonasphyxiated normothermic full-term neonates. A prolonged 36-hour dosing interval will be needed to achieve target gentamicin trough concentrations in this population. Further prospective evaluation of this dosing recommendation is needed.
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Affiliation(s)
- Adam Frymoyer
- Department of Pediatrics, Stanford University, Palo Alto, California 94304, USA.
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Burton AJ, Giguère S, Warner L, Alhamhoom Y, Arnold RD. Effect of age on the pharmacokinetics of a single daily dose of gentamicin sulfate in healthy foals. Equine Vet J 2012; 45:507-11. [DOI: 10.1111/j.2042-3306.2012.00683.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 09/09/2012] [Indexed: 11/30/2022]
Affiliation(s)
- A. J. Burton
- Department of Large Animal Medicine; College of Veterinary Medicine; University of Georgia; Athens; Georgia; USA
| | - S. Giguère
- Department of Large Animal Medicine; College of Veterinary Medicine; University of Georgia; Athens; Georgia; USA
| | - L. Warner
- Department of Large Animal Medicine; College of Veterinary Medicine; University of Georgia; Athens; Georgia; USA
| | - Y. Alhamhoom
- Department of Pharmaceutical and Biomedical Sciences; College of Pharmacy; College of Pharmacy; University of Georgia; Athens; Georgia; USA
| | - R. D. Arnold
- Department of Pharmaceutical and Biomedical Sciences; College of Pharmacy; College of Pharmacy; University of Georgia; Athens; Georgia; USA
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24
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Fullas F, Padomek MT, Thieman CJ, Van Gorp AE. Comparative evaluation of six extended-interval gentamicin dosing regimens in premature and full-term neonates. Am J Health Syst Pharm 2011; 68:52-6. [PMID: 21164066 DOI: 10.2146/ajhp100114] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Six extended-interval gentamicin dosing regimens were comparatively evaluated in premature and full-term neonates. METHODS Data regarding six physician-ordered dosing regimens of gentamicin for neonates in a hospital neonatal intensive care unit were collected and analyzed. Neonates of gestational age (GA) 29 weeks or younger received 4.5 mg/kg every 48 hours. Neonates of GA 30-34 weeks received one of three dosing regimens: 3.5, 4, or 4.5 mg/kg every 36 hours. Neonates of GA 35 weeks or older received either 3.5 or 4 mg/kg every 24 hours. Blood samples were collected 30 minutes before and 30 minutes after the third dose was infused for binary trough and peak level determinations, respectively. RESULTS Peak gentamicin concentrations in the target range were attained most often in neonates of GA 29 weeks or younger who received gentamicin 4.5 mg/kg every 48 hours, in neonates of GA 30-34 weeks treated with gentamicin 3.5 mg/kg every 36 hours, and in neonates of GA 35 weeks or older treated with gentamicin 3.5 mg/kg every 24 hours. CONCLUSION For neonates of GA 30-34 weeks, gentamicin 3.5 mg/kg every 36 hours resulted in the highest percentage of peaks in the target range compared with 4 and 4.5 mg/kg every 36 hours. For neonates of GA 35 weeks or older, gentamicin 3.5 mg/kg every 24 hours provided the highest percentage of peaks in the target range compared with 4 mg/kg every 24 hours. The differences between the percentages of trough values in the target range of 0.5-2 μg/mL were not significant among dosing subgroups within each age group.
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Affiliation(s)
- Fekadu Fullas
- Pharmacy Department, St. Luke’s Regional Medical Center, 2720 Stone Park Boulevard, Sioux City, IA 51104, USA.
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26
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Nielsen EI, Sandström M, Honoré PH, Ewald U, Friberg LE. Developmental pharmacokinetics of gentamicin in preterm and term neonates: population modelling of a prospective study. Clin Pharmacokinet 2009; 48:253-63. [PMID: 19492870 DOI: 10.2165/00003088-200948040-00003] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVE Preterm and term newborn infants show wide interindividual variability (IIV) in pharmacokinetic parameters of gentamicin. More extensive knowledge and use of predictive covariates could lead to faster attainment of therapeutic concentrations and a reduced need for concentration monitoring. This study was performed to characterize the population pharmacokinetics of gentamicin in preterm and term neonates and to identify and quantify relationships between patient characteristics and IIV. A secondary aim was to evaluate cystatin C as a marker for gentamicin clearance in this patient population. METHODS Data were collected in a prospective study performed in the Neonatal Intensive Care Unit at the University Children's Hospital, Uppsala, Sweden. Population pharmacokinetic modelling was performed using nonlinear mixed-effects modelling (NONMEM) software. Bodyweight was included as the primary covariate according to an allometric power model. Other evaluated covariates were age (postmenstrual age, gestational age [GA], postnatal age [PNA]), markers for renal function (serum creatinine, serum cystatin C) and concomitant medication with cefuroxime, vancomycin or indometacin. Covariate-parameter relationships were explored using a stepwise covariate model building procedure. The predictive performance of the developed model was evaluated using an independent external dataset for a similar patient population. RESULTS Sixty-one newborn infants (GA range 23.3-42.1 weeks, PNA range 0-45 days) were enrolled in the study. In total, 894 serum gentamicin samples were included in the analysis. The concentration-time profile was described using a three-compartment model. Gentamicin clearance increased with the GA and PNA (included in a nonlinear fashion). The GA was also identified as having a significant influence on the central volume of distribution, with a preterm neonate having a larger central volume of distribution per kilogram of bodyweight than a term neonate. Cystatin C and creatinine were not correlated with gentamicin clearance in this study population. The external dataset was well predicted by the developed model. CONCLUSION Bodyweight and age (GA and PNA) were found to be major factors contributing to IIV in gentamicin clearance in neonates. Based on these data, cystatin C and serum creatinine were not correlated with gentamicin clearance and therefore not likely to be predictive markers of renal function in this patient population. Based on predictions from the developed model, preterm neonates do not reach targeted peak and trough gentamicin concentrations after a standard dosage regimen of 4 mg/kg given once daily, suggesting a need for higher loading doses and prolonged dosing intervals in this patient population.
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Affiliation(s)
- Elisabet I Nielsen
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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Schreuder MF, Wilhelm AJ, Bökenkamp A, Timmermans SMH, Delemarre-van de Waal HA, van Wijk JAE. Impact of gestational age and birth weight on amikacin clearance on day 1 of life. Clin J Am Soc Nephrol 2009; 4:1774-8. [PMID: 19713296 DOI: 10.2215/cjn.02230409] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Intrauterine growth restriction (IUGR) and prematurity are associated with a low nephron endowment. It can therefore be expected that neonates who are born premature and/or after IUGR have a lower GFR. Measurement of GFR in neonates is difficult, but the clearance of amikacin has been proven to be a reliable marker. We hypothesized that amikacin clearance is lower after IUGR or premature birth as a marker of low nephron endowment. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Amikacin clearance was retrospectively analyzed in 161 neonates who received amikacin within the first 24 h of life. Using the MW/Pharm computer program, a population one-compartment model was calculated. The mean population pharmacokinetic parameters were individualized for each patient according to the maximum a posteriori Bayesian fitting method and provided the amikacin clearance. RESULTS Our results show that birth weight z score and gestational age are correlated with the clearance of amikacin (partial correlation coefficient 0.159, P = 0.046, and 0.396, P < 0.001, respectively), after correction for other factors. CONCLUSIONS We conclude that renal clearance on the first day of life is lower in neonates with a lower gestational age and/or birth weight z score. This indicates that both prematurity and IUGR impair GFR on the first day of life.
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Affiliation(s)
- Michiel F Schreuder
- Department of Pediatric Nephrology, 804, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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Anderson GD, Lynn AM. Optimizing pediatric dosing: a developmental pharmacologic approach. Pharmacotherapy 2009; 29:680-90. [PMID: 19476420 DOI: 10.1592/phco.29.6.680] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Many physiologic differences between children and adults can result in age-related differences in pharmacokinetics. Understanding the effects of age on bioavailability, volume of distribution, protein binding, hepatic metabolic isoenzymes, and renal elimination can provide insight into optimizing doses for pediatric patients. We performed a search of English-language literature using the MEDLINE database regarding age and pharmacokinetics (1979-July 2008). We then evaluated the literature with an emphasis on drugs with one primary elimination pathway, such as renal clearance or a pathway involving a single metabolic isoenzyme. Our mechanistic-based analysis revealed that children need weight-corrected doses that are substantially higher than adult doses for drugs that are metabolically eliminated solely by the specific cytochrome P450 (CYP) isoenzymes CYP1A2, CYP2C9, and CYP3A4. In contrast, weight-corrected doses for drugs eliminated by renal excretion or metabolism involving CYP2C19, CYP2D6, N-acetyltransferase 2, or uridine diphosphate glucuronosyltransferases are similar in children and adults. In children, bioavailability of drugs with high first-pass metabolism is decreased for drugs metabolized by CYP1A2, CYP2C9, and CYP3A4. Limited data suggest that by age 5 years, bioavailability of drugs affected by efflux transporters should be equivalent to that of adults. Using a pharmacokinetics-based approach, rational predictions can be made for the effects of age on drugs that undergo similar pathways of elimination, even when specific pharmacokinetic data are limited or unavailable.
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Affiliation(s)
- Gail D Anderson
- Department of Pharmacy, University of Washington, Seattle, Washington 98195, USA.
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Touw DJ, Westerman EM, Sprij AJ. Therapeutic drug monitoring of aminoglycosides in neonates. Clin Pharmacokinet 2009; 48:71-88. [PMID: 19271781 DOI: 10.2165/00003088-200948020-00001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The efficacy and toxicity of aminoglycosides show a strong direct positive relationship with blood drug concentrations, therefore, therapy with aminoglycosides in adults is usually guided by therapeutic drug monitoring. Dosing regimens in adults have evolved from multiple daily dosing to extended-interval dosing. This evolution has also taken place in neonates. Neonates, however, display large interindividual differences in the pharmacokinetics of aminoglycosides due to developmental differences early in life. The volume of distribution of aminoglycosides shows a strong relationship with bodyweight, which tends to be larger (corrected for bodyweight) in more premature infants and those with sepsis. Renal clearance of aminoglycosides increases with gestational age and accelerates immediately after birth. Because of these developmental influences, there is great inter- and intraindividual variability in the volume of distribution and clearance of these drugs, and investigators have established aminoglycoside dosing regimens based on bodyweight and/or gestational age. Widely practised dosing regimens comprise 4-5 mg/kg bodyweight of gentamicin every 24-48 hours as a first dose, followed by dose adjustment based on therapeutic drug monitoring. Although formal toxicity studies are scarce, there is no evidence that aminoglycoside toxicity in neonates differs from that in adults. Monitoring of blood drug concentrations and intelligent reconstruction of individual pharmacokinetic behaviour using a population pharmacokinetic model, optimally chosen blood sampling times and appropriate pharmacokinetic software, help clinicians to quickly optimize aminoglycoside dosing regimens to maximize the clinical effect and minimize the toxicity of these drugs.
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Begg EJ, Vella-Brincat JWA, Robertshawe B, McMurtrie MJ, Kirkpatrick CMJ, Darlow B. Eight years' experience of an extended-interval dosing protocol for gentamicin in neonates. J Antimicrob Chemother 2009; 63:1043-9. [DOI: 10.1093/jac/dkp073] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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González Santacruz M, Tarazona Fargueta JL, Ferrandis Rodríguez P, Tapia Collados C, Jiménez Cobo B. [Comparison of two gentamicin dosing schedules in the newborn]. An Pediatr (Barc) 2008; 68:581-8. [PMID: 18559197 DOI: 10.1157/13123290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Gentamicin is widely used in full-term neonates as empirical therapy for early-onset suspected or proven sepsis. Several dosing schedules for gentamicin have been recommended for this neonatal population. OBJECTIVE To compare gentamicin serum levels, efficacy and toxicity of two dosing schedules in term and preterm newborns. MATERIAL AND METHODS The study included 200 newborns who were started on gentamicin therapy. Group A (N=100) was prescribed a multiple-daily dosing regimen and Group B (N=100) on a once-daily dosing regimen. Newborns in Group A received gentamicin at 2.5-3.5 mg/kg/dose q12-18 h depending on postnatal age and serum creatinine levels, and newborns in Group B received 4-5 mg/kg/dose q24-48 h depending on postconceptional and postnatal age. All peak and trough serum drug levels, demographic data, and markers of potential nephrotoxicity and ototoxicity were compared. RESULTS Peak serum gentamicin levels were significantly higher (8.2+/-0.22 microg/ml vs. 5.9+/-0.13 microg/ml; p <or= 0.001) and trough levels were significantly lower (0.9+/-0.06 microg/ml vs. 1.7+/-0.08 microg/ml; p <or= 0.001) in Group B than in Group A. There was no significant difference between the groups either in the clinical failure rate or in the nephrotoxicity or ototoxicity outcomes. CONCLUSIONS Once-daily dosing regimen of gentamicin in preterm and term newborns is safe and effective, with a reduced risk of serum drug concentrations falling outside the therapeutic range.
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Affiliation(s)
- M González Santacruz
- Servicio de Pediatría, Sección de Neonatología, Hospital General Universitario de Alicante, Alicante, España.
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Two nomograms for determining extended-dosing intervals for gentamicin in neonates. Am J Health Syst Pharm 2008; 65:624-30. [PMID: 18359969 DOI: 10.2146/ajhp070314] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The development of two nomograms to predict dosing intervals for gentamicin in neonates based on one gentamicin concentration is described. METHODS Pooled data from three retrospective studies on neonates age seven days or younger were used to create nomograms that would predict dosing intervals for gentamicin. The population volume of distribution (0.45 L/kg) and a determined half-life were used to create nomogram cutoff concentrations that could select a dosing interval for neonates to achieve steady-state trough concentrations of < or =0.5 or < or =1 mg/L. A dose of 4 mg/kg was used to simulate concentration-versus-time profiles for included neonates based on their individual pharmacokinetic data. Predicted concentrations from hours 6 to 22, at one-hour intervals, for each neonate were compared against the nomograms and evaluated for the number of correct interval predictions. The nomograms were considered to have failed at any time point where they indicated an interval that would not have achieved the desired trough concentration of < or =0.5 or < or =1 mg/L or if the interval chosen was longer than necessary. RESULTS The 0.5- and 1-mg/L nomograms predicted correct dosing intervals for 81-92% of neonates for postinfusion hours between 15 to 21 and 86-93% for postinfusion hours of 13 and 21, respectively. Accuracy of the nomograms to predict correct dosing intervals improved as the postinfusion time before the next concentration measurement increased. CONCLUSION Using the two nomograms may help predict the correct extended-dosing intervals of gentamicin administration for neonates. Prospective evaluation and validation of the nomograms may be necessary for their wider use as a clinical tool.
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Pullen J, Driessen M, Stolk LML, Degraeuwe PLJ, van Tiel FH, Neef C, Zimmermann LJI. Amoxicillin Pharmacokinetics in (Preterm) Infants Aged 10 to 52 Days: Effect of Postnatal Age. Ther Drug Monit 2007; 29:376-80. [PMID: 17529898 DOI: 10.1097/ftd.0b013e318067de5c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The pharmacokinetic parameters of amoxicillin were determined in 32 newborn infants aged 10 to 52 days (mean postnatal age, 24.7 +/- 12.4 days) to improve amoxicillin dosing in this age group. Amoxicillin plasma concentrations were determined using reversed-phase high-performance liquid chromatography in surplus plasma samples from routine gentamicin assays. Amoxicillin pharmacokinetic parameters (mean +/- SD) were as follows: first-order elimination constant (K(el)) = 0.27 +/- 0.10 h(-1), volume of distribution corrected for body weight (V/W) = 0.66 +/- 0.27 L/kg, total body clearance corrected for body weight (CL/W) = 0.18 +/- 0.10 Lkg(-1)h(-1), and elimination half-life (t(1/2)) = 3.0 +/- 1.3 hours. Amoxicillin body clearance was approximately twofold greater in our patients compared with published values in younger neonates (mean postnatal age, 0.76 +/- 1.57 days). Simulation studies using the observed amoxicillin pharmacokinetic data suggest an amoxicillin dose of 40 mg/kg administered every 8 hours in infants older than 9 days postnatal age, independent of gestational age and postconceptional age, to achieve satisfactory target plasma amoxicillin concentrations less than 140 mg/L and time above minimum inhibitory concentration of at least 40%. Prospective evaluation of this suggested new dosage regimen is necessary before implementation in the care of ill neonates.
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Affiliation(s)
- J Pullen
- Department of Clinical Pharmacy and Toxicology, University Hospital of Maastricht, Maastricht, The Netherlands.
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Pullen J, de Rozario L, Stolk LML, Degraeuwe PLJ, van Tiel FH, Zimmermann LJI. Population pharmacokinetics and dosing of flucloxacillin in preterm and term neonates. Ther Drug Monit 2006; 28:351-8. [PMID: 16778719 DOI: 10.1097/01.ftd.0000211831.96102.91] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In total 235 flucloxacillin total (free+protein bound) plasma concentrations were determined in 55 neonates (gestational age 26 to 42 weeks, postnatal age 0 to 44 days) with reversed-phase HPLC in surplus plasma samples from routine gentamicin assays. Population pharmacokinetic parameters were calculated according to an one compartment open model with iterative two-stage Bayesian fitting (MWPHARM 3.50, Mediware, The Netherlands). Mean clearance corrected for weight was 0.18+/-0.10 L kgh and volume of distribution corrected for weight was 0.54+/-0.17 L/kg. Pearson correlations between the individual pharmacokinetic parameters and covariates, like gestational age, plasma creatinine, and gentamicin clearance, were low and therefore not relevant for use in clinical practice. Total plasma concentrations above 200 mg/L were considered toxic and T>MIC (time above minimum inhibitory free plasma concentration) of more than 40% was considered effective. Protein binding was assumed to be 86.3% in all neonates, based on literature. The current dosage regimen, 25 or 50 mg/kg every 8 or 12 hours, did not result in effective plasma concentrations for the treatment of Staphylococcus aureus in 17 (31%) of the 55 neonates. Therefore, the authors suggest an initial dose of 25 mg/kg/4 h for all neonates, irrespective of their age, based on the breakpoint MIC value of flucloxacillin for Staphylococcus aureus (2.0 mg/L). After isolation of the causative agent of infection, flucloxacillin administration ought to be reconsidered based on the expected susceptibility pattern of the isolate. When oxacillin sensitive coagulase negative staphylococci are isolated, the initial dose should be reduced to 10 mg/kg/6 h, based on the breakpoint MIC value of 0.25 mg/L. Simulation with these new dosage regimens indicated that satisfactory plasma concentrations were reached in 52 of the 55 neonates. However, the regimens need prospective verification. Moreover, the exact role of neonatal protein binding needs to be further investigated.
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Affiliation(s)
- Joyce Pullen
- Department of Clinical Pharmacy, University Hospital of Maastricht, The Netherlands.
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Pullen J, Stolk LML, Nieman FHM, Degraeuwe PLJ, van Tiel FH, Zimmermann LJI. Population pharmacokinetics and dosing of amoxicillin in (pre)term neonates. Ther Drug Monit 2006; 28:226-31. [PMID: 16628135 DOI: 10.1097/01.ftd.0000198648.39751.11] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Amoxicillin plasma concentrations, pharmacokinetic parameters, and the influence of demographic, anthropometric, and clinical covariates were investigated in 150 neonates. Gestational age (GA) ranged from 25 to 42 weeks and mean postnatal age (PNA) was 0.8 days. Amoxicillin concentrations were measured with reversed-phase HPLC in surplus plasma from routine assays of coadministered gentamicin. Mean total body clearance corrected for body weight (CL/W) was 0.096 +/- 0.036 L/kg(-1)h(-1), mean elimination half-life (t(1/2)) was 5.2 +/- 1.9 hours, and mean volume of distribution corrected for body weight (V/W) was 0.65 +/- 0.13 L/kg. Multiple regression equations were calculated for the prediction of CL/W amoxicillin. CL/W gentamicin, V/W gentamicin, and GA were significant predictors of CL/W amoxicillin. Amoxicillin peak and trough concentrations after the second dose and the time the concentration exceeds the minimum inhibitory concentration (T>MIC), reached with the current dosage regimen, were evaluated. Toxic plasma concentrations were reached in several patients. Therefore, the authors have proposed a lower dosage regimen, based on GA, population pharmacokinetic parameters, bacterial susceptibility (T>MIC), and possible toxicity: 15 mg/kg per 8 hours and 20 mg/kg per 8 hours for neonates with GA < or = 34 and GA>34 weeks, respectively. Simulation with this new dosage regimen indicated that satisfactory plasma concentrations were reached in all 150 neonates. Therefore, use of therapeutic drug monitoring and pharmacokinetic calculations for dosage adjustment is generally not necessary.
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Affiliation(s)
- Joyce Pullen
- Department of Clinical Pharmacy and Toxicology, University Hospital of Maastricht, The Netherlands.
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Lingvall M, Reith D, Broadbent R. The effect of sepsis upon gentamicin pharmacokinetics in neonates. Br J Clin Pharmacol 2005; 59:54-61. [PMID: 15606440 PMCID: PMC1884965 DOI: 10.1111/j.1365-2125.2005.02260.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
AIM To investigate the effect of sepsis upon the volume of distribution (Vd) of gentamicin in neonates. METHODS A retrospective chart review was conducted of neonates admitted to Dunedin Hospital who had gentamicin concentrations performed between 1st January 2000 and 30th October 2003. Data from 277 neonates, including a total of 576 gentamicin concentrations, were included in the pharmacokinetic analysis. Fifteen (5.4%) of the neonates had confirmed sepsis. Pharmacokinetic analyses were performed with NONMEM using a one compartment first order elimination model. Duration of infusion (D) was included as a parameter in the model. Covariates included sepsis (SEP), chronological age, gestational age (GA), birth weight, current weight, gender, Apgar score at 1 (AP1) and 5 (AP2) minutes, plasma C-reactive protein and serum creatinine. RESULTS The initial model provided a mean estimates of clearance (CL) of 0.0460 l kg(-1) h(-1), volume of distribution (Vd) of 0.483 l kg(-1) and D of 0.748 h. The magnitudes of interpatient variability, expressed as CV%, were 29.2% for CL, 20.8% for Vd and 71.5% for D. The magnitude of residual variability in gentamicin concentrations was 88.0%. The final pharmacokinetic model was: CL = (0.0177 + 0.00147.(GA-20) + 0.000635.AP2) l kg(-1) h(-1), Vd = (0.483 +0.0656. sepsis) l kg(-1), D = 0.672 h. The interpatient variability (CV%) was 22.8% for CL, 22.8% for Vd and 97.7% for D. The magnitude of residual variability in gentamicin concentrations was 83.3%. CONCLUSIONS The 14% increase in Vd in septic neonates implies that larger doses may be required to achieve peak therapeutic concentrations in the presence of sepsis. D is an important parameter in neonatal pharmacokinetic models.
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Murphy JE. Prediction of gentamicin peak and trough concentrations from six extended-interval dosing protocols for neonates. Am J Health Syst Pharm 2005; 62:823-7. [PMID: 15821275 DOI: 10.1093/ajhp/62.8.823] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
PURPOSE The ability of six extended-interval gentamicin dosing protocols to achieve desired peak and trough concentrations in neonates was evaluated using simulated calculations based on pooled patient data. METHODS The demographic and pharmacokinetic data of 293 neonates age one week or less from three previously published studies were pooled and applied in each of six published protocols. The data collected, including weight, dosage, dosing interval, and measured serum or plasma gentamicin concentrations, were used to determine gentamicin clearance, elimination-rate constant, and distribution volume. Peak and trough gentamicin concentrations were calculated and compared with several therapeutic ranges that aim to achieve high peak concentrations for maximum efficacy and low trough concentrations for minimum toxicity. RESULTS All protocols resulted in more than 95% of peak concentrations exceeding 5 mg/L. Peaks exceeded 10 mg/L in 26-42% of the simulations. Most of the protocols resulted in high trough concentrations (0.5-1.5 mg/L). Trough concentrations were below 1 mg/L in 51-83% of the simulations. CONCLUSION Simulated calculations based on pooled patient data found that six gentamicin dosing protocols for neonates would likely yield acceptable peak concentrations and a trough concentration of < or = 1 mg/L for at least 50% of patients. It may be sufficient to monitor only the trough concentrations when applying these protocols.
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Affiliation(s)
- John E Murphy
- Department of Pharmacy Practice and Science, and Assistant Dean, University of Arizona College of Pharmacy, P.O. Box 210207, Tucson, AZ 85721-0207, USA.
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de Hoog M, Mouton JW, van den Anker JN. Thoughts on "Population pharmacokinetics and relationship between demographic and clinical variables and pharmacokinetics of gentamicin in neonates". Ther Drug Monit 2003; 25:256-7; author reply 257. [PMID: 12657925 DOI: 10.1097/00007691-200304000-00020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Letters to the Editor. Ther Drug Monit 2003. [DOI: 10.1097/00007691-200304000-00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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