Meta-analysis of European placebo controlled studies of vigabatrin in drug resistant epilepsy.

1. A meta-analysis has been performed on nine placebo controlled trials of vigabatrin (GVG) administered as add-on therapy to patients suffering from drug resistant epilepsy. 2. There were two pilot placebo-controlled dose ranging studies, six double-blind crossover studies and a multicentre response controlled study. 3. There were a total of 398 patients entered and 390 have been evaluated for safety and 337 for efficacy. 4. In spite of the difficulties in the clinical evaluation of new antiepileptic drug, a reduction in seizure frequency was reported following the addition of vigabatrin to the concomitant medication in all studies. This was statistically significant in the larger of the two pilot studies, the multicentre study and three of the six double-blind studies. 5. There was a statistically significant reduction in seizures of in all six double-blind studies when the 98 patients suffering from complex partial seizures with or without generalisation were considered. Seventy two percent of these patients showed a greater than 25% reduction in seizure frequency. 6. Vigabatrin was well tolerated. The frequency of adverse events was similar to that reported elsewhere.