This review of randomised controlled trials showed that vigabatrin can reduce seizure frequency in people with drug-resistant partial epilepsy. Short-term follow-up of patients showed that some side effects were associated with its use. Further analysis of longer-term observational studies is required to evaluate how likely patients are to develop visual field defects and whether such side effects are associated with dose and duration of drug use.
gamma-Vinyl GABA: a double-blind placebo-controlled trial in partial epilepsy.
The antiepileptic effect of gamma-vinyl gamma-aminobutyric acid (GABA), an irreversible GABA-transaminase inhibitor, was investigated in an add-on, placebo-controlled, double-blind, cross-over, fixed-dose trial. Twenty-one patients suffering from difficult to control complex partial seizures participated; 18 patients completed the trial. Serum levels of concomitant antiepileptic drugs were kept constant throughout the trial. Three patients (17%) experienced a 75% reduction in seizure frequency and in 8 (44%) the seizures were reduced by at least 50%. Two patients developed a moderate and 1 patient a marked increase in seizure frequency during treatment with gamma-vinyl GABA. Except for 2 patients who had to discontinue the trial because of adverse effects of gamma-vinyl GABA, the participants were unable to discriminate between treatment regimens with regard to side effects. gamma-vinyl GABA seems to be a promising new antiepileptic drug, and the first one to present convincing evidence of a GABAergic mechanism of action.