Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Clin Pharmacokinet ; 63(7): 999-1014, 2024 07.
Artículo en Inglés | MEDLINE | ID: mdl-38955947

RESUMEN

BACKGROUND AND OBJECTIVE: Pediatric dosing of enoxaparin was derived based on extrapolation of the adult therapeutic range to children. However, a large fraction of children do not achieve therapeutic anticoagulation with initial dosing. We aim to use real-world anti-Xa data obtained from children receiving enoxaparin per standard of care to characterize the population pharmacokinetics (PopPK).Author names: Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Also, kindly confirm the details in the metadata are correct.The author names are accurately presented and the metadata are correct.  METHODS: A PopPK analysis was performed using NONMEM, and a stepwise covariate modeling approach was applied for the covariate selection. The final PopPK model, developed with data from 1293 patients ranging in age from 1 day to 18 years, was used to simulate enoxaparin subcutaneous dosing for prophylaxis and treatment based on total body weight (0-18 years, TBW) or fat-free mass (2-18 years, FFM). Simulated exposures in children with obesity (body mass index percentile ≥95th percentile) were compared with those without obesity. RESULTS: A linear, one-compartment PopPK model that included allometric scaling using TBW (<2 years) or FFM (≥2 years) characterized the enoxaparin pharmacokinetic data. In addition, serum creatinine was identified as a significant covariate influencing clearance. Simulations indicated that in patients aged <2 years, the recommended 1.5 mg/kg TBW-based dosing achieves therapeutic simulated concentrations. In pediatric patients aged ≥2 years, the recommended 1.0 mg/kg dose resulted in exposures more comparable in children with and without obesity when FFM weight-based dosing was applied. CONCLUSION: Using real-world data and PopPK modeling, enoxaparin's pharmacokinetics were characterized in pediatric patients. Using FFM and twice-daily dosing might reduce the risk of overdosing, especially in children with obesity.


Asunto(s)
Anticoagulantes , Enoxaparina , Modelos Biológicos , Humanos , Enoxaparina/farmacocinética , Enoxaparina/administración & dosificación , Niño , Preescolar , Adolescente , Lactante , Femenino , Masculino , Anticoagulantes/farmacocinética , Anticoagulantes/administración & dosificación , Recién Nacido , Peso Corporal , Relación Dosis-Respuesta a Droga , Medicina de Precisión/métodos
2.
Pharmacotherapy ; 43(7): 638-649, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-35607886

RESUMEN

STUDY OBJECTIVE: Treatment of HIV and tuberculosis co-infection leads to significant mortality in pediatric patients, and treatment can be challenging due to the clinically significant drug-drug interaction (DDI) between lopinavir/ritonavir (LPV/RTV) and rifampin. Doubling LPV/RTV results in insufficient lopinavir trough concentrations in pediatric patients. The objective of this study was to leverage physiologically based pharmacokinetic (PBPK) modeling to optimize the adjusted doses of LPV/RTV in children receiving the WHO-revised doses of rifampin (15 mg/kg daily). DESIGN: Adult and pediatric PBPK models for LPV/RTV with rifampin were developed, including CYP3A and P-glycoprotein inhibition and induction. SETTING (OR DATA SOURCE): Data for LPV/RTV model development and evaluation were available from the pediatric AIDS Clinical Trials Group. PATIENTS: Dosing simulations were next performed to optimize dosing in children (2 months to 8 years of age). INTERVENTION: Exposure following super-boosted LPV/RTV with 10 and 15 mg/kg PO daily rifampin was simulated. MEASUREMENTS AND MAIN RESULTS: Simulated parameters were within twofold observations for LPV, RTV, and rifampin in adults and children ≥2 weeks old. The model predicted that, in healthy adults receiving 400/100 mg oral LPV/RTV twice daily (BID), co-treatment with 600 mg oral rifampin daily decreased the steady-state area under the concentration vs. time curve of LPV by 79%, in line with the observed change of 75%. Simulated and observed concentration profiles were comparable for LPV/RTV (230/57.5 mg/m2 ) PO BID without rifampin and 230/230 mg/m2 LPV/RTV PO BID with 10 mg/kg PO daily rifampin in pediatric patients. Sixteen mg/kg of super-boosted LPV (LPV/RTV 1:1) PO BID with 15 mg/kg PO daily rifampin achieved simulated LPV troughs >1 mg/L in ≥93% of virtual children weighing 3.0-24.9 kg, which was comparable with 10 mg/kg PO daily rifampin. CONCLUSIONS: Super-boosted LPV/RTV with 15 mg/kg rifampin achieves therapeutic LPV troughs in HIV/TB-infected simulated children.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , Inhibidores de la Proteasa del VIH , Adulto , Humanos , Niño , Lopinavir/efectos adversos , Ritonavir , Rifampin/uso terapéutico , Interacciones Farmacológicas , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico
3.
CPT Pharmacometrics Syst Pharmacol ; 11(6): 778-791, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35491971

RESUMEN

Obesity is an increasingly alarming public health threat, with nearly 20% of children classified as obese in the United States today. Children with obesity are commonly prescribed the opioids fentanyl and methadone, and accurate dosing is critical to reducing the risk of serious adverse events associated with overexposure. However, pharmacokinetic studies in children with obesity are challenging to conduct, so there is limited information to guide fentanyl and methadone dosing in these children. To address this clinical knowledge gap, physiologically-based pharmacokinetic models of fentanyl and methadone were developed in adults and scaled to children with and without obesity to explore the interplay of obesity, age, and pharmacogenomics. These models included key obesity-induced changes in physiology and pharmacogenomic effects. Model predictions captured observed concentrations in children with obesity well, with an overall average fold error of 0.72 and 1.08 for fentanyl and methadone, respectively. Model simulations support a reduced fentanyl dose (1 vs. 2 µg/kg/h) starting at an earlier age (6 years) in virtual children with obesity, highlighting the importance of considering both age and obesity status when selecting an infusion rate most likely to achieve steady-state concentrations within the target range. Methadone dosing simulations highlight the importance of considering genotype in addition to obesity status when possible, as cytochrome P450 (CYP)2B6*6/*6 virtual children with obesity required half the dose to match the exposure of wildtype children without obesity. This physiologically-based pharmacokinetic modeling approach can be applied to explore dosing of other critical drugs in children with obesity.


Asunto(s)
Analgésicos Opioides , Fentanilo , Adulto , Analgésicos Opioides/farmacocinética , Niño , Humanos , Metadona/efectos adversos , Metadona/farmacocinética , Obesidad/tratamiento farmacológico
4.
Clin Pharmacol Ther ; 112(2): 391-403, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35451072

RESUMEN

Dosing guidance for children with obesity is often unknown despite the fact that nearly 20% of US children are classified as obese. Enoxaparin, a commonly prescribed low-molecular-weight heparin, is dosed based on body weight irrespective of obesity status to achieve maximum concentration within a narrow therapeutic or prophylactic target range. However, whether children with and without obesity experience equivalent enoxaparin exposure remains unclear. To address this clinical question, 2,825 anti-activated factor X (anti-Xa) surrogate concentrations were collected from the electronic health records of 596 children, including those with obesity. Using linear mixed-effects regression models, we observed that 4-hour anti-Xa concentrations were statistically significantly different in children with and without obesity, even for children with the same absolute dose (P = 0.004). To further mechanistically explore obesity-associated differences in anti-Xa concentration, a pediatric physiologically-based pharmacokinetic (PBPK) model was developed in adults, and then scaled to children with and without obesity. This PBPK model incorporated binding of enoxaparin to antithrombin to form anti-Xa and elimination via heparinase-mediated metabolism and glomerular filtration. Following scaling, the PBPK model predicted real-world pediatric concentrations well, with an average fold error (standard deviation of the fold error) of 0.82 (0.23) and 0.87 (0.26) in children with and without obesity, respectively. PBPK model simulations revealed that children with obesity have at most 20% higher 4-hour anti-Xa concentrations under recommended, total body weight-based dosing compared to children without obesity owing to reduced weight-normalized clearance. Enoxaparin exposure was better matched across age groups and obesity status using fat-free mass weight-based dosing.


Asunto(s)
Enoxaparina , Tromboembolia Venosa , Adulto , Anticoagulantes , Niño , Enoxaparina/uso terapéutico , Heparina de Bajo-Peso-Molecular , Humanos , Obesidad , Tromboembolia Venosa/tratamiento farmacológico
5.
Front Pharmacol ; 13: 818726, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35359853

RESUMEN

Childhood obesity is an alarming public health problem. The pediatric obesity rate has quadrupled in the past 30 years, and currently nearly 20% of United States children and 9% of children worldwide are classified as obese. Drug distribution and elimination processes, which determine drug exposure (and thus dosing), can vary significantly between patients with and without obesity. Obesity-related physiological changes, such as increased tissue volume and perfusion, altered blood protein concentrations, and tissue composition can greatly affect a drug's volume of distribution, which might necessitate adjustment in loading doses. Obesity-related changes in the drug eliminating organs, such as altered enzyme activity in the liver and glomerular filtration rate, can affect the rate of drug elimination, which may warrant an adjustment in the maintenance dosing rate. Although weight-based dosing (i.e., in mg/kg) is commonly practiced in pediatrics, choice of the right body size metric (e.g., total body weight, lean body weight, body surface area, etc.) for dosing children with obesity still remains a question. To address this gap, the interplay between obesity-related physiological changes (e.g., altered organ size, composition, and function), and drug-specific properties (e.g., lipophilicity and elimination pathway) needs to be characterized in a quantitative framework. Additionally, methodological considerations, such as adequate sample size and optimal sampling scheme, should also be considered to ensure accurate and precise top-down covariate selection, particularly when designing opportunistic studies in pediatric drug development. Further factors affecting dosing, including existing dosing recommendations, target therapeutic ranges, dose capping, and formulations constraints, are also important to consider when undergoing dose selection for children with obesity. Opportunities to bridge the dosing knowledge gap in children with obesity include modeling and simulating techniques (i.e., population pharmacokinetic and physiologically-based pharmacokinetic [PBPK] modeling), opportunistic clinical data, and real world data. In this review, key considerations related to physiology, drug parameters, patient factors, and methodology that need to be accounted for while studying the influence of obesity on pharmacokinetics in children are highlighted and discussed. Future studies will need to leverage these modeling opportunities to better describe drug exposure in children with obesity as the childhood obesity epidemic continues.

6.
J Clin Pharmacol ; 62(8): 960-969, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35119103

RESUMEN

Childhood obesity continues to rise in the United States and, with it, the off-label use of metformin for weight loss. The influence of age and obesity on the drug's disposition and exposure has not previously been studied using a mechanistic framework. Here, an adult physiologically based pharmacokinetic (PBPK) model of metformin was scaled to pediatric populations without obesity, with overweight/obesity, and with severe obesity; a published virtual population of children and adolescents with obesity was leveraged during model evaluation. When the pediatric model was simulated in groups aged 10 to 18 years, oral clearance following 1000 mg of metformin was higher (≈1200 mL/min) in those with obesity and severe obesity compared to the groups without and with overweight (≈1000 mL/min). In addition, simulated area under the concentration-time curve in older children and adolescents with obesity and severe obesity was comparable to that in adults with a similar dose-exposure relationship. Overall, simulations using the pediatric PBPK model support the use of adult doses of metformin in older children and adolescents with obesity. Moreover, the virtual population of children and adolescents with obesity offers a valuable tool to facilitate development of pediatric PBPK models for studying populations with obesity and, in turn, contribute information to inform drug labeling in this special population.


Asunto(s)
Metformina , Obesidad Mórbida , Obesidad Infantil , Adolescente , Adulto , Niño , Humanos , Metformina/farmacocinética , Modelos Biológicos , Sobrepeso
7.
Clin Pharmacokinet ; 61(2): 307-320, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34617262

RESUMEN

BACKGROUND AND OBJECTIVE: While one in five children in the USA are now obese, and more than three-quarters receive at least one drug during childhood, there is limited dosing guidance for this vulnerable patient population. Physiologically based pharmacokinetic modeling can bridge the gap in the understanding of how pharmacokinetics, including drug distribution and clearance, changes with obesity by incorporating known obesity-related physiological changes in children. The objective of this study was to develop a virtual population of children with obesity to enable physiologically based pharmacokinetic modeling, then use the novel virtual population in conjunction with previously developed models of clindamycin and trimethoprim/sulfamethoxazole to better understand dosing of these drugs in children with obesity. METHODS: To enable physiologically based pharmacokinetic modeling, a virtual population of children with obesity was developed using national survey, electronic health record, and clinical trial data, as well as data extracted from the literature. The virtual population accounts for key obesity-related changes in physiology relevant to pharmacokinetics, including increased body size, body composition, organ size and blood flow, plasma protein concentrations, and glomerular filtration rate. The virtual population was then used to predict the pharmacokinetics of clindamycin and trimethoprim/sulfamethoxazole in children with obesity using previously developed physiologically based pharmacokinetic models. RESULTS: Model simulations predicted observed concentrations well, with an overall average fold error of 1.09, 1.24, and 1.53 for clindamycin, trimethoprim, and sulfamethoxazole, respectively. Relative to children without obesity, children with obesity experienced decreased clindamycin and trimethoprim/sulfamethoxazole weight-normalized clearance and volume of distribution, and higher absolute doses under recommended pediatric weight-based dosing regimens. CONCLUSIONS: Model simulations support current recommended weight-based dosing in children with obesity for clindamycin and trimethoprim/sulfamethoxazole, as they met target exposure despite these changes in clearance and volume of distribution.


Asunto(s)
Clindamicina , Obesidad , Composición Corporal , Niño , Tasa de Filtración Glomerular , Humanos , Modelos Biológicos , Obesidad/tratamiento farmacológico , Combinación Trimetoprim y Sulfametoxazol/farmacocinética
8.
Clin Pharmacokinet ; 60(12): 1591-1604, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34155614

RESUMEN

BACKGROUND: Meropenem is a broad-spectrum carbapenem antibiotic approved by the US Food and Drug Administration for use in pediatric patients, including treating complicated intra-abdominal infections in infants < 3 months of age. The impact of maturation in glomerular filtration rate and tubular secretion by renal transporters on meropenem pharmacokinetics, and the effect on meropenem dosing, remains unknown. We applied physiologically based pharmacokinetic (PBPK) modeling to characterize the disposition of meropenem in preterm and term infants. METHODS: An adult meropenem PBPK model was developed in PK-Sim® (Version 8) and scaled to infants accounting for renal transporter ontogeny and glomerular filtration rate maturation. The PBPK model was evaluated using 645 plasma concentrations from 181 infants (gestational age 23-40 weeks; postnatal age 1-95 days). The PBPK model-based simulations were performed to evaluate meropenem dosing in the product label for infants < 3 months of age treated for complicated intra-abdominal infections. RESULTS: Our model predicted plasma concentrations in infants in agreement with the observed data (average fold error of 0.90). The PBPK model-predicted clearance in a virtual infant population was successfully able to capture the post hoc estimated clearance of meropenem in this population, estimated by a previously published model. For 90% of virtual infants, a 4-mg/L target plasma concentration was achieved for > 50% of the dosing interval following product label-recommended dosing. CONCLUSIONS: Our PBPK model supports the meropenem dosing regimens recommended in the product label for infants <3 months of age.


Asunto(s)
Antibacterianos , Infecciones Intraabdominales , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Tasa de Filtración Glomerular , Humanos , Lactante , Recién Nacido , Riñón , Meropenem , Persona de Mediana Edad , Modelos Biológicos , Adulto Joven
9.
Antimicrob Agents Chemother ; 65(7): e0214920, 2021 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-33903114

RESUMEN

The antibiotic combination trimethoprim (TMP)-sulfamethoxazole (SMX) has a broad spectrum of activity and is used for the treatment of numerous infections, but pediatric pharmacokinetic (PK) data are limited. We previously published population PK (popPK) models of oral TMP-SMX in pediatric patients based on sparse opportunistically collected data (POPS study) (J. Autmizguine, C. Melloni, C. P. Hornik, S. Dallefeld, et al., Antimicrob Agents Chemother 62:e01813-17, 2017, https://doi.org/10.1128/AAC.01813-17). We performed a separate PK study of oral TMP-SMX in infants and children with more-traditional PK sample collection and independently developed new popPK models of TMP-SMX using this external data set. The POPS data set and the external data set were each used to evaluate both popPK models. The external TMP model had a model and error structure identical to those of the POPS TMP model, with typical values for PK parameters within 20%. The external SMX model did not identify the covariates in the POPS SMX model as significant. The external popPK models predicted higher exposures to TMP (median overprediction of 0.13 mg/liter for the POPS data set and 0.061 mg/liter for the external data set) and SMX (median overprediction of 1.7 mg/liter and 0.90 mg/liter) than the POPS TMP (median underprediction of 0.016 mg/liter and 0.39 mg/liter) and SMX (median underprediction of 1.2 mg/liter and 14 mg/liter) models. Nonetheless, both models supported TMP-SMX dose increases in infants and young children for resistant pathogens with a MIC of 1 mg/liter, although the required dose increase based on the external model was lower. (The POPS and external studies have been registered at ClinicalTrials.gov under registration no. NCT01431326 and NCT02475876, respectively.).


Asunto(s)
Antibacterianos/farmacocinética , Combinación Trimetoprim y Sulfametoxazol/farmacocinética , Niño , Preescolar , Humanos , Lactante
10.
Clin Pharmacol Ther ; 109(1): 253-262, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32691891

RESUMEN

Physiologically-based pharmacokinetic (PBPK) modeling can potentially predict pediatric drug-drug interactions (DDIs) when clinical DDI data are limited. In infants for whom treatment of pulmonary hypertension and prevention or treatment of invasive candidiasis are indicated, sildenafil with fluconazole may be given concurrently. To account for developmental changes in cytochrome P450 (CYP) 3A, we determined and incorporated fluconazole inhibition constants (KI ) for CYP3A4, CYP3A5, and CYP3A7 into a PBPK model developed for sildenafil and its active metabolite, N-desmethylsildenafil. Pharmacokinetic (PK) data in preterm infants receiving sildenafil with and without fluconazole were used for model development and evaluation. The simulated PK parameters were comparable to observed values. Following fluconazole co-administration, differences in the fold change for simulated steady-state area under the plasma concentration vs. time curve from 0 to 24 hours (AUCss,0-24 ) were observed between virtual adults and infants (2.11-fold vs. 2.82-fold change). When given in combination with treatment doses of fluconazole (12 mg/kg i.v. daily), reducing the sildenafil dose by ~ 60% resulted in a geometric mean ratio of 1.01 for simulated AUCss,0-24 relative to virtual infants receiving sildenafil alone. This study highlights the feasibility of PBPK modeling to predict DDIs in infants and the need to include CYP3A7 parameters.


Asunto(s)
Inhibidores del Citocromo P-450 CYP3A/farmacocinética , Citocromo P-450 CYP3A/metabolismo , Interacciones Farmacológicas/fisiología , Fluconazol/farmacocinética , Citrato de Sildenafil/farmacocinética , Adolescente , Adulto , Anciano , Área Bajo la Curva , Femenino , Humanos , Recien Nacido Prematuro , Masculino , Persona de Mediana Edad , Modelos Biológicos , Adulto Joven
11.
Clin Transl Sci ; 13(6): 1189-1198, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32324313

RESUMEN

Metoclopramide is commonly used for gastroesophageal reflux. The aims of the present study were to develop a pediatric population pharmacokinetic (PopPK) model, which was applied to simulate the metoclopramide exposure following dosing used in clinical practice. Opportunistic pharmacokinetic data were collected from pediatric patients receiving enteral or parenteral metoclopramide per standard of care and these data were simultaneously fitted using NONMEM. Allometric scaling with body weight was included a priori in the model. Using the final model, the steady-state maximum concentrations (Css,max ) and the area under the metoclopramide plasma concentration-time curve at steady state from 0 to 6 hours (AUCss,0-6h ) were simulated following 0.1 or 0.15 mg/kg orally every 6 hours in virtual patients, and compared with previously reported ranges associated with toxicity or the efficacy for gastroesophageal reflux in infants. A two-compartment model with first-order absorption best characterized 87 concentration measurements from 50 patients (median [range] postnatal age of 8.89 years [0.01-19.13]). There were 20 infants (≤ 2 years), 9 children (2 years to age ≤ 12 years), and 21 adolescents (> 12 years). Body weight was the only covariate included in the final model. For > 75% of virtual patients, simulated Css,max and AUCss,0-6h estimates were within the range associated with efficacy for gastroesophageal reflux in infants; however, slightly lower exposures were predicted in virtual patients < 2 years. Our study suggests that a metoclopramide enteral dose of 0.1 mg/kg every 6 hours, which was previously recommended for pediatric patients, results in simulated exposure generally within suggested ranges for the treatment of gastroesophageal reflux.


Asunto(s)
Reflujo Gastroesofágico/tratamiento farmacológico , Metoclopramida/farmacocinética , Modelos Biológicos , Adolescente , Área Bajo la Curva , Peso Corporal , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Reflujo Gastroesofágico/sangre , Humanos , Lactante , Recién Nacido , Masculino , Metoclopramida/administración & dosificación , Metoclopramida/efectos adversos , Resultado del Tratamiento , Adulto Joven
12.
CPT Pharmacometrics Syst Pharmacol ; 8(7): 500-510, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31087536

RESUMEN

Fluconazole is used to treat hematogenous Candida meningoencephalitis in preterm and term infants. To characterize plasma and central nervous system exposure, an adult fluconazole physiologically-based pharmacokinetic (PBPK) model was scaled to infants, accounting for age dependencies in glomerular filtration and metabolism. The model was optimized using 760 plasma samples from 166 infants (median postmenstrual age (range) 28 weeks (24-50)) and 27 cerebrospinal fluid (CSF) samples from 22 infants (postmenstrual age 28 weeks (24-33)). Simulations evaluated achievement of the surrogate efficacy target of area under the unbound concentration-time curve ≥ 400 mg • hour/L over the dosing interval in plasma and CSF using dosing guidelines. Average fold error of predicted concentrations was 0.73 and 1.14 for plasma and CSF, respectively. Target attainment in plasma and CSF was reached faster after incorporating a loading dose of 25 mg/kg. PBPK modeling can be useful in exploring CNS kinetics of drugs in children.


Asunto(s)
Antifúngicos/farmacocinética , Líquido Cefalorraquídeo/química , Fluconazol/farmacocinética , Plasma/química , Área Bajo la Curva , Ensayos Clínicos como Asunto , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Masculino , Modelos Teóricos , Programas Informáticos
13.
Clin Pharmacokinet ; 58(7): 899-910, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30810947

RESUMEN

BACKGROUND: Infants with acute lymphoblastic leukemia (ALL) treated with high-dose methotrexate may have reduced methotrexate clearance (CL) due to renal immaturity, which may predispose them to toxicity. OBJECTIVE: The aim of this study was to develop a population pharmacokinetic (PK) model of methotrexate in infants with ALL. METHODS: A total of 672 methotrexate plasma concentrations were obtained from 71 infants enrolled in the Children's Oncology Group (COG) Clinical Trial P9407. Infants received methotrexate 4 g/m2 intravenously for four cycles during weeks 4-12 of intensification. A population PK analysis was performed using NONMEM® version 7.4. The final model was evaluated using a non-parametric bootstrap and a visual predictive check. Simulations were performed to evaluate methotrexate dose and the utility of a bedside algorithm for dose individualization. RESULTS: Methotrexate was best characterized by a two-compartment model with allometric scaling. Weight was the only covariate included in the final model. The coefficient of variation for interoccasion variability (IOV) on CL was relatively high at 25.4%, compared with the interindividual variability for CL and central volume of distribution (10.7% and 13.2%, respectively). Simulations identified that 21.1% of simulated infants benefitted from bedside dose adjustment, and adjustment of methotrexate doses during infusions can avoid supratherapeutic concentrations. CONCLUSION: Infants treated with high-dose methotrexate demonstrated a relatively high degree of IOV in methotrexate CL. The magnitude of IOV in the CL of methotrexate suggests that use of a bedside algorithm may avoid supratherapeutic methotrexate concentrations resulting from high IOV in methotrexate CL.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacocinética , Metotrexato/farmacocinética , Modelos Biológicos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Femenino , Humanos , Lactante , Masculino , Medicina de Precisión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA