Double-blind, placebo-controlled trial of topiramate (600 mg daily) for the treatment of refractory partial epilepsy

Purpose: We wished to evaluate adjunctive therapy for partial-onset seizures with topiramate (TPM) for efficacy and safety in a double-blind, placebo-controlled, randomized, parallel-group study. Methods: Sixty outpatients with epilepsy (47 men and 13 women, mean age 32.9 years) were studied. All had a documented history of partial-onset seizures with or without secondarily generalized seizures. After an 8-week baseline during which patients had at least one seizure per week, 30 patients each were randomized to TPM 300 mg twice daily (b.i.d.) or placebo for 12 weeks. Results: TPM was significantly superior to placebo, as indicated by all efficacy assessments: greater median percent reduction from baseline in the average monthly seizure rate (46 vs. -12%, p = 0.004); greater number of treatment responders (patients with ≤50% reduction in seizure rate) (47 vs. 10%, p = 0.001), and better investigator (p = 0.002) and patient (p = 0.010) global assessments of treatment. Among TPM-treated patients, the most commonly reported adverse events (AE) were headache, somnolence, fatigue, dizziness, and abnormal thinking. Most AE were mild or moderate in severity. Conclusions: The results of the present trial indicate that TPM 600 mg/day is effective in the treatment of refractory partial-onset seizures with or without secondarily generalized seizures.