Therapeutic Drug Monitoring of Lacosamide in Chinese Pediatric Patients with Epilepsy: Efficacy and Factors Influencing the Plasma Concentration.

Background And Objective: The impact of individual patient variables on drug metabolism is particularly important for antiseizure medication, and lacosamide has not been studied in Chinese pediatric patients with epilepsy. This study evaluated the effects of dose, age, sex, medication time, seizure type, and concomitant enzyme-inducing antiseizure medications (EIASMs) on the plasma concentration of lacosamide.

Methods: A total of 500 pediatric patients from two hospitals in China were enrolled in this study. Lacosamide plasma concentration was processed using an ultra-performance liquid chromatography assay. Efficacy was evaluated based on the four-grade therapeutic effect criteria developed by the first National Epilepsy Academic Conference of the Chinese Medical Association.

Results: The responder rate to lacosamide therapy was 72.2% (361/500). There was a weaker relationship between the lacosamide daily dose and lacosamide plasma concentration (r = 0.238). Lacosamide plasma concentrations of patients ranged from 1.5 to 19.7 µg/mL, with a mean of 6.9 ± 3.2 µg/mL. The study results showed a significant contribution of age, body mass index, epilepsy duration, medication time, and EIASMs to the lacosamide plasma concentration (p < 0.05). Patients taking concomitant EIASMs with lacosamide had a significantly lower mean lacosamide plasma concentration (5.9 ± 2.6 µg/mL) than patients taking concomitant non-EIASMs (7.5 ± 3.5 µg/mL, p < 0.001).

Conclusion: To ensure the clinical efficacy and safety of lacosamide therapy in pediatric patients, it is necessary to monitor the plasma concentration.