Population Pharmacokinetic Model of Lacosamide in Chinese Children and Adults with Epilepsy

To examine the pharmacokinetics of lacosamide (LCM) in Chinese children and adults with epilepsy and to establish a population pharmacokinetic model. A one-compartment model with first-order absorption and elimination was constructed using 482 plasma samples from 391 individuals. Nonlinear mixed-effects modeling accounted for intraindividual and interindividual variabilities. Covariate effects were evaluated through forward inclusion and backward elimination, and the model performance was validated using goodness-of-fit plots and visual predictive checks. The final population pharmacokinetic (PPK) model indicated that a higher body weight and lower urea levels were associated with increased LCM clearance (CL). Coadministration of phenobarbital or carbamazepine resulted in a 1.42-fold increase in LCM CL. The absorption rate constant was fixed at 0.13, with typical values of CL and apparent volume of distribution (Vd) being 1.19 L/h and 9.95 L, respectively. The association between pharmacokinetic parameters and covariates was quantified as follows: (IND1 = 0.35 if comedicated with phenobarbital or carbamazepine; otherwise = 0). The PPK model developed in this study plays a pivotal role in optimizing and personalizing LCM therapy for patients with epilepsy.