Abstract: Objective To assess the correlation of efficacy, safety and serum concentrations of lacosamide (LCM) in children with epilepsy under 4 years of age. Methods A total of 190 children with epilepsy treated with LCM from January 1, 2019 to December 31, 2023 in the Children's Hospital of Xinjiang Uygur Autonomous Region were retrospectively enrolled, and personal data were collected, and blood concentrations, efficacy, and adverse drug reactions of LCM were recorded. The correlation between efficacy, safety, and plasma concentrations was analyzed. Results The response rate of LCM treatment in children with epilepsy was 77.37%, and the incidence of adverse reactions was 31.58%. The accuracy of the LCM plasma concentration in predicting efficacy [AUC (95%CI)=0.532 (0.440~0.623)] was higher than that of the administered dose [AUC (95%CI)=0.525 (0.422~0.628)]. The reference intervals of LCM steady-state plasma concentration in children with epilepsy were 1.50~14.65 μg·mL^-1, respectively. The plasma concentration of LCM in the children with adverse reactions was significantly higher than that in the children without adverse reactions [(7.93±3.90) μg·mL^-1 and (6.44±3.10) μg·mL^-1, P < 0.05]. Conclusion LCM has well efficacy and safety in the treatment of Childern with epicepsy under 4 years, and can be used for clinical epicepsy treatment.

Key words: lacosamide, epilepsy, plasma concentration, efficacy, safety, children, adverse drug reactions