ZONISAMIDE FOR ADD-ON TREATMENT OF REFRACTORY PARTIAL EPILEPSY - A EUROPEAN DOUBLE-BLIND TRIAL

The new antiepileptic drug zonisamide was evaluated in a European mult icenter parallel-group double-blind trial as add-on treatment for 139 patients with refractory partial epilepsy. During treatment with zonis amide complex partial seizures decreased by 27.7% compared to placebo (P <0.05) and the median rate dropped from 12/month to 7.1/month with no changes in the placebo group (P <0.007). During the 12-week double- blind phase a 50% reduction of all seizures was recorded in 29.9% of t he patients treated with zonisamide vs. 9.4% during placebo. Complete remission was observed during treatment with zonisamide in 6.2%.The pl asma concentrations of the concomitant antiepileptic drugs did not cha nge markedly when zonisamide was added. Adverse events, mostly fatigue , somnolence, dizziness and ataxia, occurred in 59.2% of the patients compared to 27.9% during placebo. Zonisamide was withdrawn in two pati ents due to adverse events. Kidney stones were not observed nor any re levant clinical chemistry or hematological changes. Zonisamide is an e ffective antiepileptic drug for add-on treatment of refractory partial epilepsy.