Oxcarbazepine (Trileptal) as monotherapy in patients with partial seizures

To evaluate the efficacy and safety of oxcarbazepine (OXC) as monotherapy for patients with uncontrolled partial seizures.

A multicenter, double-blind, randomized, parallel-group, dose-controlled monotherapy trial compared OXC at 2400 mg/day with OXC at 300 mg/day in patients with uncontrolled partial-onset seizures previously receiving carbamazepine (CBZ) monotherapy. During a 28-day open-label conversion phase, patients were tapered off CBZ and titrated to OXC 2400 mg/day. After a 56-day open-label baseline phase on OXC 2400 mg/day, patients entered a 126-day double-blind treatment phase in which they were randomized to continue OXC at 2400 mg/day or were down titrated over 6 weeks to OXC at 300 mg/day. Patients met the efficacy endpoint by completing the double-blind treatment phase or by meeting one of four predefined exit criteria. The primary efficacy variable was time to meeting one of the exit criteria. The secondary efficacy variable was the percentage of patients meeting one of the exit criteria in each of the two treatment groups.

Of the 143 patients enrolled, 96 were randomized in the double-blind treatment phase. Time to meeting an exit criterion was significantly in favor of the OXC 2400 mg/day group (p = 0.0001). The median time to meeting an exit criterion was 68 days for the OXC 2400 mg/day Group and 28 days for the OXC 300 mg/day Group. In addition, the percentage of patients meeting one of the exit criteria was significantly lower for the OXC 2400 mg/day Group (p = 0.0001). Overall, OXC was well tolerated with the most common adverse events consisting of fatigue, nausea, ataxia, and headache.

This trial demonstrated that OXC at 2400 mg/day is well tolerated and efficacious when administered as monotherapy in patients with uncontrolled partial onset seizures.