A DOUBLE-BLIND TRIAL OF GABAPENTIN MONOTHERAPY FOR NEWLY-DIAGNOSED PARTIAL SEIZURES

Background: Gabapentin is widely approved as add-on therapy for epilep sy treatment for partial seizures with and without secondary generaliz ation. To investigate the efficacy of gabapentin administered as monot herapy in patients with newly diagnosed partial epilepsy, a randomized double-blind trial was performed. Methods: Eligible patients were ran domized to receive one of three masked doses of gabapentin (300, 900, or 1,800 mg/day) or open-label carbamazepine (600 mg/day) and kept dai ly seizure diaries throughout the study. After titration, patients ent ered a 24-week evaluation phase. Patients were required to exit the st udy if they experienced an exit event, defined as a total of three sim ple or complex partial seizures, one generalized tonic-clonic (GTC) se izure, or status epilepticus. Patients could be withdrawn for lack of efficacy, adverse events, or noncompliance. Kaplan-Meier statistics we re used to estimate the probability that patients would continue in th e study without having an exit event. Results: Time to exit event was longer for patients on 900 mg/day (n = 72) or 1,800 mg/day (n = 74) of gabapentin than for patients receiving 300 mg/day (n = 72; p = 0.0395 and 0.0175, respectively). The most clinically relevant measure of re tention on treatment (exit event plus adverse event withdrawal rate) w as similar for carbamazepine (n = 74) and 1,800 mg/day gabapentin (54% versus 57%) but was lower (better) for 900 mg/day gabapentin (44%). N o unexpected new adverse events emerged with gabapentin monotherapy. C onclusions: Gabapentin at 900 or 1,800 mg/day is effective and safe as monotherapy for patients with newly diagnosed partial epilepsy.