Vigabatrin in complex partial seizures: a long-term study.

The efficacy and safety of oral vigabatrin (VGB) as add-on therapy in the long-term treatment of poorly controlled epilepsy were evaluated in 19 patients with complex partial seizures, either with or without secondary generalization. The study was run with a single-blind, placebo-controlled, crossover design, and included 2 months of placebo and 13-15 months of treatment with VGB, at doses ranging from 1 to 4 g/day. Of the 14 patients who completed the trial, 2 were seizure free, in 5 seizure frequency dropped by more than 75\% and in another 5 by more than 50\% with respect to baseline. The decrease in seizure frequency in the group as a whole was significant at all observation points of the trial. Three patients were not entered into the long-term phase due to lack of improvement (an increase in seizure frequency was observed in one of them), and 2 were excluded later because improvement disappeared leading to unauthorized changes in comedication. Side effects were mild and never caused discontinuation of treatment. In conclusion, VGB showed a remarkable efficacy and safety in the long-term treatment of complex partial seizures