Zonisamide

ZONISAMIDE

Zonisamide is a sulfonamide derivative. Its primary site of action appears to be the Na⁺ channel; it also acts on T-type voltage-gated Ca²⁺ channels. The drug is effective against partial and generalized tonic-clonic seizures and may also be useful against infantile spasms and certain myoclonias. It has good bioavailability, linear kinetics, low protein-binding, renal excretion, and a half-life of 1–3 days. Dosages range from 100 to 600 mg/d in adults and from 4 to 12 mg/d in children. Adverse effects include drowsiness, cognitive impairment, and potentially serious skin rashes. Zonisamide does not interact with other antiseizure drugs.