An Open, Randomized, Multicenter Comparative Clinical Trial of Lamotrigine and Carbamazepine as Initial Monotherapy in Previously Untreated Epilepsies

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Abstract

PURPOSE: To evaluate the efficacy and safety of lamotrigine compared to carbamazepine as the initial drug for previously untreated epilepsies.
METHODS
Previously untreated epileptic patients were randomly allocated into the lamotrigine (LTG) and the carbamazepine (CBZ) groups in 2 : 1 ratio. During titration phase, starting dose of LTG was 25 mg/day, which was increased to 50 mg/day, 100 mg/day, and 200 mg/day every 2 weeks, while CBZ was started with 100 mg/day and increased to 200 mg/day, 400 mg/day, and 600 mg/day accordingly. The maintenance phase varied from 24 weeks to 44 weeks. The primary efficacy measure was the completion rate and the secondary efficacy measures were the seizure remission rate for 24 weeks and the time to first seizure during the maintenance phase. The safety measures included the incidence of adverse events (AEs), and the premature withdrawal rate related to AEs.
RESULTS
A total of 393 patients were recruited and randomly allocated into LTG group (n=264) and CBZ group (n=129). The completion rate was 65% in LTG group and 70% in CBZ group (p=0.51). Comparison of the seizure remission rate for 24 weeks and the time to first seizure were not different between the two drugs. Premature withdrawal rate due to AEs was 9.1% in LTG group and 7.8% in CBZ group (p=0.66) and skin rash was the most frequent cause of early drug withdrawal in both groups. Among patients who had completed the trial as scheduled, more patients in the LTG group than CBZ were taking the initial target dose or less (89% and 73%, p=0.001).
CONCLUSION
The efficacy and safety of LTG and CBZ as initial drug were comparable; however, LTG was more effective than CBZ at their initial target doses.