Pregabalin as adjunctive therapy for partial seizures

The efficacy and safety of pregabalin as adjunctive therapy for patients with partial epilepsy with or without secondary generalization has been studied in three randomized, double-blind, placebo-controlled trials involving 1,052 patients. Patients (greater than or equal to 12 years of age) participating in the trials were highly refractory to treatment, experiencing at least six seizures and no 4-week seizure-free period during the 8-week baseline phase, even though 73% received at least two antiepileptic drugs and 23% received three. Each fixed-dose study was 12 weeks in duration. In Study 1, patients received pregabalin 50, 150, 300, or 600 mg/day given two times daily with no titration period. Studies 2 and 3 had a 1-week titration to dose levels of 150 and 600 mg/day given three times daily (Study 2), 600 mg/day given two times daily, and 600 mg/day given three times daily (Study 3). Pregabalin, at 150, 300, and 600 mg/day, was significantly superior to placebo in reducing seizure frequency with a clear dose-response relationship. Responder rates, defined as the percentage of patients with >50% reduction in seizure frequency from baseline, approached 50% at 600 mg/day. In the effective dose range (150-600 mg/day), seizure freedom in the last 28 days of treatment was 3-17%. There was no difference between two times daily and three times daily dosing regimens. Efficacy was apparent as early as week one. The most commonly reported adverse events were CNS related, and either mild or moderate in intensity and generally self limiting. Few patients (>5% in any treatment group) discontinued due to lack of efficacy. These results indicate that pregabalin is highly effective as adjunctive therapy in the treatment of patients with partial seizures with or without secondary generalization.