Zonisamide (ZNS) is a broad-spectrum antiepileptic drug in both animal models of epilepsy and patients with epilepsy. It is effective for both localization-related and generalized epilepsies and appears to be particularly potent in progressive myoclonic epilepsy syndromes. Its pharmokinetic profile is favorable, with a long half-life and low protein binding. However, its insolubility may make the development of a parenteral formulation difficult. Its safety profile is good, although teratogenicity in animal models is of concern. Adult doses of 400-600 mg per day in two doses, with blood levels from 20 to 30 mg/ml, appear to be effective.