Zonisamide: A Multimodal Antiepileptic Agent in Contemporary Practice

Course overview

Zonisamide is a sulfonamide-derived antiepileptic drug with broad-spectrum activity, mediated by inhibition of sodium and T-type calcium channels and by weak carbonic anhydrase inhibition. It is primarily indicated as adjunctive therapy for partial-onset seizures in adults, with off-label applications in chronic pain, weight management, and other neurologic conditions. Once-daily dosing, hepatic metabolism via CYP3A4, and renal elimination support its use across diverse populations, although adverse effects, including CNS depression, metabolic acidosis, and rare serious reactions such as Stevens-Johnson syndrome and neuropsychiatric events, require careful monitoring. This course reviews zonisamide's pharmacology, therapeutic applications, special population considerations, adverse effect profile, toxicity, drug interactions, and the role of interprofessional collaboration in safe and effective seizure management.