Open label pilot study of oxcarbazepine for inpatients under evaluation for epilepsy surgery

Oxcarbazepine (OXC) is a keto analogue of carbamazepine with no epoxide metabolite. We performed an open-label pilot study of OXC in six men and four women undergoing presurgical evaluation for complex partial or secondarily generalized seizures. Mean age was 34.3 ± 8.3 years, and mean duration of epilepsy was 18.2 ± 11.1 years. Patients were monitored for approximately 7 days before entry into an open-label add-on OXC study. Baseline antiepileptic medications were stopped in seven of the ten patients prior to initiating OXC. OXC was titrated to 2,400 mg/day in two divided doses over 2-3 days. The baseline daily seizure frequency was 0.75 ± 0.49, compared to 0.19 ± 0.31 seizures per day during the 10 days subjects were on OXC (P = .04, two-tailed paired t test). Overall, 80% of patients showed at least a 50% reduction in seizures, and the mean reduction was to 32% of the baseline. Adverse events consisted of nausea (20%), ataxia (10%), fatigue (10%), blurred vision (10%), and pruritus (10%). Segmented neutrophil counts, serum sodium, and serum AST declined with OXC. This pilot study suggests preliminary evidence for safety and efficacy of OXC.