Zonisamide
Zonisamide is an anticonvulsant medication primarily used as adjunctive therapy for treating partial-onset seizures in adults with epilepsy. Although its precise mechanism of action is not fully understood, zonisamide demonstrates anticonvulsant activity in several experimental models and is effective against certain seizure types. It is typically prescribed when monotherapy alone has not provided adequate seizure control.
Zonisamide is an antiepileptic drug used as add-on therapy to control partial seizures in adults with epilepsy.
Key facts at a glance
- ATC
- N03AX15
- RxNorm
- 39998
- Generic
- Zonisamide
- Class
- atc-n03
- Brands
- Zonisade, Zonegran
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule, tablet, suspension
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Zonisamide is FDA-approved as adjunctive treatment for partial-onset seizures (focal seizures) in adults with epilepsy. It is used when other antiepileptic medications have not provided sufficient seizure control on their own.
The exact mechanism is unknown, but zonisamide demonstrates anticonvulsant effects in multiple experimental seizure models. It may work through various mechanisms, including blocking sodium channels and reducing excitatory neurotransmission, contributing to its seizure-preventing effects.
Common side effects include dizziness, drowsiness, appetite loss, and difficulty with concentration. Adequate hydration is recommended to reduce the risk of kidney stones. Treatment should be initiated and monitored by a healthcare provider, as dose adjustments may be needed. Do not stop taking zonisamide abruptly without medical guidance.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy