LONG-TERM FOLLOW-UP-STUDY OF VIGABATRIN IN THE TREATMENT OF REFRACTORY EPILEPSY

Thirty adult patients with drug-resistant partial epilepsy who had res ponded favorably to add-on vigabatrin under placebo-controlled conditi ons were maintained on long-term treatment with the drug. Twenty patie nts are still in the trial with a follow-up ranging from 26 to 70 mont hs (median, 60). Ten patients were withdrawn from the study after havi ng received the drug for 4-14 months (median, 9) because of seizure br eakthrough (n = 7) and other reasons (n = 3). Overall, the initially f avorable therapeutic response was generally maintained during the long -term treatment. Side effects were minor, the most frequent being a mo derate gain in body weight. Plasma concentrations of phenytoin were si gnificantly reduced during vigabatrin treatment. Our findings suggest that vigabatrin retains its anticonvulsant efficacy in about two-third s of the patients after a 5-year follow-up period. Tolerability is als o good during long-term treatment.