Zonisamide is a sulfonamide anticonvulsant used to treat partial seizures. Zonisamide may act by blocking repetitive firing of voltage-gated sodium channels, leading to a reduction of T-type calcium channel currents or by binding allosterically to GABA receptors.
- Mechanism
- Curator reviewed · 11 references
The mechanism of action by which zonisamide controls seizures has not been fully established. However, its antiepileptic properties may be due to its effects on sodium and calcium channels. Zonisamide blocks sodium channels and reduces voltage-dependent, transient inward currents, stabilizing neuronal membranes and suppressing neuronal hypersynchronization. It affects T-type calcium currents, but has no effect on L-type calcium currents.
Zonisamide suppresses synaptically-driven electrical activity by altering the synthesis, release, and degradation of neurotransmitters, such as glutamate, gamma-aminobutyric acid (GABA), dopamine, serotonin (5-hydroxytryptamine 5-HT), and acetylcholine. Furthermore, it binds to the GABA/benzodiazepine receptor ionophore complex without producing changes in chloride flux. In vitro studies have suggested that zonisamide does not affect postsynaptic GABA or glutamate responses, nor the neuronal or glial uptake of [3H]-GABA.
- Primary indication
- Zonisamide capsules are indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.Curator reviewed · 2 structured indications
- Formula / weight
- C8H8N2O3S · 212.226 g/mol (avg)
- First approval
- United States, 2000 · European Union, 2016
- Code names
- AD-810 · CI-912 · PD-110843
- Brand names
Resolves to
UBQNRHZMVUUOMG-UHFFFAOYSA-NSMILESNS(=O)(=O)CC1=NOC2=CC=CC=C12What you can answer from here — as of September 23, 2026
Which drugs share a target with Zonisamide, and which of those have an active Phase 3 trial?
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