Nonfocal generalized tonic-clonic seizures: Response during long-term topiramate treatment

Purpose: A total of 131 adults and children (mean age, 27 years; range, 3-5 9 years) with generalized tonic-clonic seizures (GTCS) of nonfocal origin r esistant to other antiepileptic drugs (AEDs) were treated with open-label t opiramate (TPM) after completing double-blind placebo-controlled trials. Results: The mean duration of open-label TPM treatment was 387 days (range, 14-909 days); the mean TPM dose was 7 mg/kg/day (range, 1-16 mg/kg/day). A t the last study visit, the frequency of GTCS was reduced greater than or e qual to 50% from baseline in 63% of patients and by greater than or equal t o 75% in 44%. Among patients treated greater than or equal to 6 months, 16% were GTCS free greater than or equal to 6 months despite a pretreatment se izure frequency of one GTCS/week (median). Treatment with TPM was being con tinued in 82% of patients (n = 107) at the last visit. During treatment per iods of up to 2.5 years, 11 (8%) patients discontinued TPM because of adver se events and seven (5%) because of inadequate seizure control. Conclusions: TPM therapy was well tolerated, and seizure control was mainta ined with long-term, open-label therapy in patients with GTCS, leading to p rolonged seizure-free intervals in some patients with seizures previously r esistant to AED therapy.