Topiramate, carbamazepine and valproate monotherapy: double-blind comparison in newly diagnosed epilepsy

To compare topiramate (TPM) with investigator's choice of carbamazepine (CBZ) or valproate (VPA) for initial treatment in patients with newly diagnosed epilepsy.

In patients with epilepsy diagnosed within previous 3 months, investigators selected CBZ (600 mg/day) or VPA (1250 mg/day) as preferred therapy based on the patient's clinical presentation. Based on investigators' treatment choice, patients (n=613) were assigned to the CBZ or VPA treatment branch. Within each branch, patients were randomized to double-blind treatment with the traditional antiepileptic drugs (CBZ or VPA), TPM 100 mg/day, or TPM 200 mg/day. Patients continued double-blind treatment until exiting the study or until 6 months after last patient randomized.

No statistically significant differences between fixed doses of TPM and CBZ or VPA were observed in efficacy measures: time to exit, time to first seizure, and the proportion of patients seizure-free during the last 6 months of treatment. TPM 100 mg/day was associated with the fewest discontinuations due to adverse events.

In patients with newly diagnosed epilepsy, an initial target dose of TPM 100 mg/day is at least as effective as therapeutic doses of CBZ and VPA.