Zonisamide in West syndrome.

Zonisamide (ZNS), a new antiepileptic drug developed in Japan, is being used as the initial treatment of West syndrome in some Japanese institutes. The reported response rate varied from 20 to 38%. The cryptogenic patients showed a better response than the symptomatic patients. A striking finding was that the response to ZNS is rapid; most of the children who responded did so within 1-2 weeks of starting ZNS at a dose of 4-8 mg/kg/day. No serious side effects have been reported so far. ZNS may be both effective and well tolerated for the initial treatment of selected patients with West syndrome.