Dose effects of lacosamide as add-on therapy for partial-onset seizure in adult

The objective of the study was to evaluate the dose effects of lacosamide on the efficacy and safety as adjunctive therapy for partial-onset seizure in adults. We searched online databases such as Pubmed, Embase, Cochrane Online Library, and Clinicaltrial.gov for randomized control trials. A meta-analysis was performed on RevMan 5.3 software. Four randomized control trials with 1855 patients out of 310 citations and 30 registered trials were identified. 400 mg/d was more effective than 200 mg/d [RR 1.23 (95 % CI 1.05-1.45), P = 0.01], but the 600 mg/d didn't show more benefit than 400 mg/d [RR 1.01 (95 % CI 0.81-1.27), P = 0.90]. Increasing the dosage led to higher incidence of quitting the medication because of adverse events [400 vs. 200 mg/d RR 2.17 (95 % CI 1.15-4.11), P = 0.02; 600 vs. 400 mg/d RR 1.55 (95 % CI 1.12-2.15), P = 0.009]. Incidence of serious adverse events did not occur with the increase of dose [400 vs. 200 mg/d RR 1.26 (95 % CI 0.50-3.20), P = 0.62], [600 vs. 400 mg/d RR 0.52 (95 % CI 0.21-1.30), P = 0.16]. A dose of 400 mg/d resulted in a higher chance of dizziness [RR 1.50 (95 % CI 1.02-2.20), P = 0.04], vomiting [RR 1.73 (95 % CI 1.03-2.90), P = 0.04], and diplopia [RR 1.98 (95 % CI 1.19-3.30), P = 0.008] than that of 200 mg/d. 400 mg/d is the optimal dose for efficacy. The dose of 200 mg/d has the best safety for less occurrence of adverse events and less quitting. Current evidence suggests that a dose of 600 mg/d is unnecessary, except for particular reasons.