RESUMO
PURPOSE: To evaluate the efficacy of vigabatrin and valproic acid add-on therapy in the treatment of uncontrolled partial-onset seizures through randomized active controlled parallel-group trial. METHODS: Criteria for entry included a requirement for three or more partial seizures per month despite the blood level of carbamazepine was within therapeutic range. During the 56-day baseline period, patients had at least 6 partial onset seizures. Vigabatrin or valproic acid were administered as the second drug in a randomized fashion. RESULTS: Forty one patients completed the trial(21 for vigabatrin, 20 for valproic acid). There is no statistically significant difference in age, age at onset, baseline seizure frequency, dose of carbamazepine, and serum level of carbamazepine between two groups. Two patients of vigabatrin-treated group and three patients of valproic acid treated group were dropped out because of side effects. The mean vigabatrin and valproic acid does were 2809 and 1490 mg, respectively. The percentage of patients achieving at least a 50% reduction in seizure frequency at the end of 8-week of add-on trial was 62% among vigabatrin-treated patients and was 50% for patients who received valproic acid(not statistically different). There was no significant difference in seizure reduction, percent seizure reduction, and truncated percent seizure reduction between two groups. The side effects were mild and transient neurotoxic symptoms in the patients who completed the trial(5 patients for vigabatrin, 10 patients for valproic acid). CONCLUSIONS: This trial indicates that vigabatrin and valproic acid are safe and effective in the treatment of intractable partial-onset seizures. The efficacy of vigabatrin as a new add-on antiepileptic drug is comparable to the previous valproic acid carbamazepine combination in the sense of seizure reduction and maybe even superior to that in the consideration of side effects