{"title":"癫痫患者左乙拉西坦的人群药代动力学和剂量模拟:肾功能和苯妥英联合给药的影响。","authors":"Noppaket Singkham, Apinya Boonpeng, Pasiri Sithinamsuwan, Juthathip Suphanklang","doi":"10.1002/jcph.70101","DOIUrl":null,"url":null,"abstract":"<p><p>Levetiracetam (LEV) exhibits considerable interindividual pharmacokinetic variability; however, data in Thai populations remain limited. This study aimed to develop a population pharmacokinetic model of LEV, identify covariates affecting clearance, and inform individualized dosing strategies. A total of 374 LEV plasma concentrations from 264 Thai patients with epilepsy were analyzed using nonlinear mixed-effects modeling. The median age was 65.3 years (range 18.09-97.71). LEV pharmacokinetics was characterized by a one-compartment model with first-order elimination and proportional residual variability. The typical apparent clearance and volume of distribution were estimated at 2.61 L/h and 56.3 L, respectively. Clearance was significantly influenced by creatinine clearance (CrCL), estimated using the Cockcroft-Gault equation with adjusted body weight, and by phenytoin co-administration. Phenytoin increased clearance by 43.1%, while reduced CrCL was associated with lower clearance. Monte Carlo simulations demonstrated that both trough concentrations and the probability of achieving therapeutic targets (12-46 mg/L) declined with increasing CrCL, especially in patients receiving phenytoin. Standard 12-h dosing was generally sufficient for patients with impaired renal function who were not receiving phenytoin. In contrast, subtherapeutic exposure was more frequent in those with preserved or augmented renal function, particularly when phenytoin was co-administered. These findings support the use of higher or more frequent dosing in these subgroups. The final model provides a framework for individualized LEV dosing. Prospective studies are needed to validate these findings and guide their implementation in clinical practice.</p>","PeriodicalId":48908,"journal":{"name":"Journal of Clinical Pharmacology","volume":" ","pages":""},"PeriodicalIF":2.3000,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Population Pharmacokinetics and Dose Simulation of Levetiracetam in Patients with Epilepsy: Influence of Renal Function and Phenytoin Co-Administration.\",\"authors\":\"Noppaket Singkham, Apinya Boonpeng, Pasiri Sithinamsuwan, Juthathip Suphanklang\",\"doi\":\"10.1002/jcph.70101\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Levetiracetam (LEV) exhibits considerable interindividual pharmacokinetic variability; however, data in Thai populations remain limited. This study aimed to develop a population pharmacokinetic model of LEV, identify covariates affecting clearance, and inform individualized dosing strategies. A total of 374 LEV plasma concentrations from 264 Thai patients with epilepsy were analyzed using nonlinear mixed-effects modeling. The median age was 65.3 years (range 18.09-97.71). LEV pharmacokinetics was characterized by a one-compartment model with first-order elimination and proportional residual variability. The typical apparent clearance and volume of distribution were estimated at 2.61 L/h and 56.3 L, respectively. Clearance was significantly influenced by creatinine clearance (CrCL), estimated using the Cockcroft-Gault equation with adjusted body weight, and by phenytoin co-administration. Phenytoin increased clearance by 43.1%, while reduced CrCL was associated with lower clearance. Monte Carlo simulations demonstrated that both trough concentrations and the probability of achieving therapeutic targets (12-46 mg/L) declined with increasing CrCL, especially in patients receiving phenytoin. Standard 12-h dosing was generally sufficient for patients with impaired renal function who were not receiving phenytoin. In contrast, subtherapeutic exposure was more frequent in those with preserved or augmented renal function, particularly when phenytoin was co-administered. These findings support the use of higher or more frequent dosing in these subgroups. The final model provides a framework for individualized LEV dosing. Prospective studies are needed to validate these findings and guide their implementation in clinical practice.</p>\",\"PeriodicalId\":48908,\"journal\":{\"name\":\"Journal of Clinical Pharmacology\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":2.3000,\"publicationDate\":\"2025-09-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Clinical Pharmacology\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1002/jcph.70101\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Clinical Pharmacology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1002/jcph.70101","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Population Pharmacokinetics and Dose Simulation of Levetiracetam in Patients with Epilepsy: Influence of Renal Function and Phenytoin Co-Administration.
Levetiracetam (LEV) exhibits considerable interindividual pharmacokinetic variability; however, data in Thai populations remain limited. This study aimed to develop a population pharmacokinetic model of LEV, identify covariates affecting clearance, and inform individualized dosing strategies. A total of 374 LEV plasma concentrations from 264 Thai patients with epilepsy were analyzed using nonlinear mixed-effects modeling. The median age was 65.3 years (range 18.09-97.71). LEV pharmacokinetics was characterized by a one-compartment model with first-order elimination and proportional residual variability. The typical apparent clearance and volume of distribution were estimated at 2.61 L/h and 56.3 L, respectively. Clearance was significantly influenced by creatinine clearance (CrCL), estimated using the Cockcroft-Gault equation with adjusted body weight, and by phenytoin co-administration. Phenytoin increased clearance by 43.1%, while reduced CrCL was associated with lower clearance. Monte Carlo simulations demonstrated that both trough concentrations and the probability of achieving therapeutic targets (12-46 mg/L) declined with increasing CrCL, especially in patients receiving phenytoin. Standard 12-h dosing was generally sufficient for patients with impaired renal function who were not receiving phenytoin. In contrast, subtherapeutic exposure was more frequent in those with preserved or augmented renal function, particularly when phenytoin was co-administered. These findings support the use of higher or more frequent dosing in these subgroups. The final model provides a framework for individualized LEV dosing. Prospective studies are needed to validate these findings and guide their implementation in clinical practice.
期刊介绍:
The Journal of Clinical Pharmacology (JCP) is a Human Pharmacology journal designed to provide physicians, pharmacists, research scientists, regulatory scientists, drug developers and academic colleagues a forum to present research in all aspects of Clinical Pharmacology. This includes original research in pharmacokinetics, pharmacogenetics/pharmacogenomics, pharmacometrics, physiologic based pharmacokinetic modeling, drug interactions, therapeutic drug monitoring, regulatory sciences (including unique methods of data analysis), special population studies, drug development, pharmacovigilance, womens’ health, pediatric pharmacology, and pharmacodynamics. Additionally, JCP publishes review articles, commentaries and educational manuscripts. The Journal also serves as an instrument to disseminate Public Policy statements from the American College of Clinical Pharmacology.