The results of an 8-day, controlled, multicenter study of gabapentin monotherapy in 82 hospitalized patients with refractory complex partial or secondarily generalized seizures are reported by members of the US Gabapentin Study Group. The study was conducted at 13 centers, 12 in the US and 1 in Canada, between Feb 1994 and Aug 1995. The efficacy and safety of 2 dosages, 300 and 3,600 mg/d, as three equally divided doses every 8 hours, were compared after tapering and discontinuing other antiepileptic medications. Patients exited the double-blind period with the occurrence of 4 seizures (46 patients), prolonged/intensified seizures (4 patients), lack of efficacy (1), or at completion of 8-day treatment (28 patients). Time to exit was significantly longer and rate of completion of the trial period was higher for patients receiving the higher 3,600 mg/d dose of gabapentin. At the higher dosage, 52% completed the study, compared to 16% at the lower dosage. Adverse dose-related events included dizziness (13% of patients), ataxia (12%), and somnolence (11%). No patient exited the study due to adverse effects of gabapentin. 
COMMENT. This short-term inpatient study in adults demonstrates that gabapentin monotherapy is an effective and safe treatment for refractory complex partial and secondarily generalized seizures. In a further dose-controlled, 26-week, multicenter study of gabapentin in 275 patients, 20% of patients completed the study, but completion rates were higher among patients who had discontinued only one AED (23%) or had been maintained on carbamazepine (27%) in addition to gabapentin.