A Population Pharmacokinetic-Pharmacogenetic Model of Lamotrigine in Chinese Children With Epilepsy

作者:Chen, Yanan; Xu, Shansen; Wang, Zhanyou; Zhao, Mingming; Wang, Huanxin; Lu, Tong; Zhao, Limei*
来源:Therapeutic Drug Monitoring, 2018, 40(6): 730-737.
DOI:10.1097/FTD.0000000000000563

摘要

Background: The pharmacokinetics of lamotrigine (LTG) is complex and varies significantly among individuals, especially among children. Therefore, this study aimed to establish a population pharmacokinetic (PPK) model of LTG in Chinese children with epilepsy and to comprehensively evaluate the effects of genetic variations in drug-metabolizing enzymes, transporters, and a transcriptional regulator on LTG pharmacokinetics. Methods: Three hundred eighty-five steady-state plasma concentrations were obtained from 179 children (age 10.72 +/- 3.05 years and body weight 46.23 +/- 17.77 kg) with epilepsy during therapeutic drug monitoring. These patients were divided into the PPK-model group (n = 121) and the PPK-validation group (n = 58) and were genotyped for UGT1A4, UGT2B7, ABCB1, ABCG2, SLC22A1, and HNF4 alpha. PPK analysis was performed by nonlinear mixed effects modeling. Results: In the final model, apparent clearance (CL/F) of LTG was estimated to be 1.48 L/h; 500 mg valproic acid, oxcarbazepine, and UGT2B7-161TT genotype changed the CL/F by -46.2, +31.1, and -21.8%, respectively. Body weight was also identified as a significant covariate affecting LTG CL/F. Conclusions: A PPK-pharmacogenetic model of LTG in Chinese children with epilepsy was successfully established with nonlinear mixed effects modeling. Genotyping for UGT2B7-161C > T may be useful in titrating the optimal LTG dose.