Abstracts

RATIONALE: Oxcarbazepine (OXC), a keto-analog to carbamazepine, has been shown to have significant efficacy as adjunctive therapy and as monotherapy for the treatment of partial-onset seizures. The aim of this study was to evaluate the long term efficacy and safety of OXC for the treatment of medically refractory partial epilepsy. METHODS: We evaluated 15 patients who completed the double blind phase of a multicenter, randomized, dose-response monotherapy trial and who had at least six months follow-up during the open label phase of the trial. OXC was titrated to maximum daily dose of 3 grams taken as adjunctive therapy or as monotherapy. We compared the monthly seizure frequency during the first 6 months and the last 2 months of the open label phase to that obtained during the prospective baseline phase that preceded the double blind phase of the trial. Statistical significance was set at p values ?0.05. RESULTS: Ten men and 5 women with a mean age of 35 years satisfied the study criteria. The monthly seizure frequency during baseline was 11.2. Compared to baseline, there was a significant reduction in monthly seizure frequency during the first 6 months and the last 2 months of the open label phase. There was a statistical trend (p=0.053) for reduction in seizure frequency during the last two months compared to the first 6 months of the open label phase. Compared to baseline, the mean reductions in monthly seizure frequency were 36% and 61% and the ?50% responder rates were 40% and 60% during the first 6 months and last two months respectively. Most of the adverse events were transient and were rated as mild or moderate in severity. CONCLUSIONS: Treatment with OXC was well tolerated and led to a significant reduction in seizure frequency. Its efficacy is maintained or improved during the first 6 months of treatment.