Abstracts

RATIONALE: Zonisamide (Zonegran [tm], ZNS) is a unique sulfonamide anticonvulsant drug approved in the US for adjunctive treatment of partial seizures. ZNS has been widely used in Japan since 1989 to treat various seizures types and epilepsy syndromes. ZNS exhibits both sodium and calcium (T-type) channel blocking properties, indicating possible efficacy across multiple seizure types. This ongoing study evaluates the effectiveness and tolerability of ZNS in patients with generalized seizures at our clinic.
METHODS: Data from an ongoing, open-label study of 15 patients (6 males and 9 females) diagnosed with generalized seizures was analyzed. Patients were started on 100 mg ZNS daily, and increased by 100 mg weekly to efficacy, or occurrence of adverse events. Seizure frequency reduction measurements, global impression scales, and adverse events were recorded at office visits.
RESULTS: Mean age at time of ZNS administration was 39.3 years. The mean dose of ZNS was 446 mg with a range of 100 - 700 mg daily. Patients were on an average of 1.7 antiepilepsy drugs (AEDs) when ZNS was initiated. A decline in seizure frequency was observed in 13 (86.7 %) patients; 8 (53.3 %) patients showed a 50% reduction. One patient has been seizure free for [gte]6 months. Fourteen subjects reported no adverse events. Two patients discontinued ZNS: one due to sedation; one due to lack of efficacy.
CONCLUSIONS: ZNS adjunctive therapy appears to be effective for the treatment of generalized seizures as noted by the improvement in seizure frequency in the majority of our population.
Support: Elan Pharmaceuticals