The first open study of zonisamide, a novel anticonvulsant, shows efficacy in mania.

1. Zonisamide, an anticonvulsant developed in Japan, is structurally similar to serotonin. Zonisamide has been proven to have a pharmacological profile that is very similar to that of carbamazepine. Thus, the effect of zonisamide was examined in 24 psychiatric patients: 15 with bipolar manic state, 6 with schizoaffective manic state, and 3 schizophrenic excitement. 2. Approximately 25% of all the patients and 33% of the bipolar manic patients showed remarkable global improvement with the addition of zonisamide. Approximately 71% of all the patients and 80% of the bipolar group had more than moderate global improvement. 3. No serious adverse reactions were found and no patients required zonisamide withdrawal. One patient developed both leukocytosis and mildly abnormal liver function test. One developed leukocytosis and another reported mild sleepiness. These reactions disappeared when zonisamide was discontinued.