ZONEGRAN (zonisamide)
Zonegran (zonisamide) is an anti-epileptic agent indicated for use as an adjunctive therapy. It is specifically approved for the treatment of partial seizures in adult patients with epilepsy. As an add-on treatment, it provides a therapeutic option for managing seizure activity in this patient population.
How ZONEGRAN Works
The precise mechanism of action of zonisamide is unknown. It is believed to exert its anticonvulsant effects by blocking sodium channels and reducing voltage-dependent, transient inward calcium currents (T-type Ca2+ currents). These actions help stabilize neuronal membranes and suppress the hypersynchronization of neurons. Additionally, zonisamide binds allosterically to the GABA/benzodiazepine receptor ionophore complex and functions as a weak carbonic anhydrase inhibitor.
Development Insights
Details
- Status
- Prescription
- First Approved
- 2000-03-27
- Routes
- ORAL
- Dosage Forms
- CAPSULE
ZONEGRAN Approval History
What ZONEGRAN Treats
2 indicationsZONEGRAN is approved for 2 conditions since its original approval in 2000. These indications span multiple therapeutic areas including oncology, immunology, and more.
- Epilepsy
- Partial Seizures
ZONEGRAN Competitive Set
ProThree rings of competition based on shared molecular targets and treated indications.
Direct competitors
Same target(s) AND same indication — head-to-head.
MoA expansion candidates
Same target(s), different indications — where else is this mechanism being explored?
Indication competitors
Same indication, different mechanism — what else might this patient receive?
Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.
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3 of 20FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.
Clinical Trial Registry
26 trials| Trial | Sponsor ID | Phase | Status | Title |
|---|---|---|---|---|
| NCT05205811 | BuZonE 2 | Ph 3 | completed | The Effects of Combination Zonisamide and Bupropion on Switching to an Electronic Cigarette |
| NCT05134857 | 18520-001 | Ph 2 | recruiting | The Zonisamide and Reinforcement for Reducing Alcohol Use (ZARRA) Study |
| NCT02901041 results posted | 2R01AA015923-06 | Ph 3 | completed | Interdisciplinary Study of A Novel Anticonvulsant in Alcoholism |
| NCT02900352 Z-Comp results posted | HM20014185 1605017700, 7R01AA024466-04 | Ph 3 | completed | Zonisamide Treatment of Alcohol Use Disorder: an Evaluation of Efficacy and Mechanism of Action |
| NCT01766128 ZONIST | ZEPD-1091 | Ph 2, Ph 3 | withdrawn | Study of Zonisamide in Early Parkinson Disease |
| NCT04388319 BuZonE results posted | BuZonE | Ph 3 | completed | Zonisamide/Bupropion Effects on Switching to Electronic Cigarettes |
| NCT01140867 results posted | E2090-S082-409 | Ph 4 | completed | Open-label, Multi-center Trial of Zonisamide as Adjunctive Therapy in Patients With Uncontrolled Partial Epilepsy |
| NCT03034538 | 15-179 | Ph 4 | suspended | An Open-Label Tolerability and Exploratory Efficacy Study of Zonisamide for Dyskinesias in Parkinson's Disease |
| NCT03376139 | AS140026-A4 W81XWh-15-2-0077 | Ph 2 | withdrawn | Zonisamide Outpatient Study |
| NCT02368431 results posted | CLNA-003-14S ICX001012A | Ph 3 | terminated | Effectiveness of Zonisamide in Alcohol Dependent Veterans |
| NCT01847469 results posted | 1211011063 01641 | Ph 2 | completed | Zonisamide in Addition to E-CPT-C for Veterans With PTSD and Comorbid Alcohol Dependence |
| NCT01685996 1207 results posted | NA_00074143 R21DA034164 | Ph 1, Ph 2 | completed | Zonisamide Augmentation of Varenicline Treatment for Smoking Cessation |
| NCT02049073 | NIHL2014 | Ph 1, Ph 2 | withdrawn | Prevention of Noise-induced Hearing Loss |
| NCT01137890 results posted | R01DA027065 R01DA027065 | Ph 1, Ph 2 | completed | Effect of Zonisamide on Cocaine Reinforcement, Craving, and Relapse |
| NCT00692003 results posted | E2090-E044-315 Eudra ID #2007-003557-91. | Ph 3 | terminated | Adjunctive Zonisamide in Primary Generalised Tonic Clonic Seizures |
| NCT01566370 ZNSBP results posted | ZNS-BP VACT MIRECC, K23AA017689 | Ph 2 | terminated | Zonisamide for Heavy Drinkers With Bipolar Disorder |
| NCT01136954 results posted | E2090-E044-313 2007-000198-53 | Ph 3 | completed | A Study to Assess the Efficacy and Safety of Adjunctive Zonisamide in Paediatric Partial Onset Seizures (CATZ Extension Study) |
| NCT00693017 results posted | E2090-E044-317 2007-003556-10 | Ph 3 | terminated | Efficacy and Safety of Adjunctive Zonisamide in Myoclonic Seizures Associated With Idiopathic Generalised Epilepsy |
| NCT00848549 results posted | E2090-E044-314 2008-001159-23 | Ph 3 | completed | Assessing The Long-Term Safety And To Explore The Long-Term Efficacy Of Zonisamide As Monotherapy In Newly Diagnosed Partial Seizures |
| NCT00713622 | E2090-E044-406 2007-005313-19 | Ph 4 | completed | Comparing The Effect On Cognition Of Adjunctive Therapy With Zonisamide Versus Sodium Valproate |
| NCT00862563 results posted | NIAAA-CIR-AA015923 P60AA013759, 1R01AA015923 | Ph 2 | terminated | Interdisciplinary Study of Two Novel Anticonvulsants in Alcoholism |
| NCT01806805 EpsilonZêta | P091104 | Ph 3 | completed | Efficacy Trial of Zonisamide for Myoclonus Dystonia |
| NCT01765608 | ZON-01 2009-015859-24 | Ph 2 | completed | Zonisamide for the Treatment of Obstructive Sleep Apnea in Overweight/Obese Patients |
| NCT00659958 | E2090-E044-407 | Ph 4 | completed | ZAGAL Study: Evaluating Effectiveness and Tolerability of Zonisamide as Adjunctive Therapy in Patients With Partial Onset Seizures Treated With Two Antiepileptic Drugs |
| NCT00566254 results posted | E2090-E044-312 2006-002515-27 | Ph 3 | completed | Efficacy and Safety of Adjunctive Zonisamide in Paediatric Partial Onset Seizures (CATZ Study) |
| NCT00363376 | 06-06-14-01 F1D-MC-X269 | Ph 3 | completed | A Study of Zonisamide to Prevent Olanzapine-Associated Weight Gain |
Active Pipeline
Ongoing clinical trials by development phase
Key Completed Trials
Completed studies with published results, ranked by significance
Trial Timeline
Full development history with FDA approval milestones
Understanding FDA Approval Types
| Count | Type | What it means |
|---|---|---|
| - | ORIG | Original approval - drug first enters market |
| - | SUPPL - Efficacy | New indication (new disease/condition approved) |
| - | SUPPL - Labeling | Label text changes (warnings, dosing updates) |
| - | SUPPL - Manufacturing | Production changes (new facility) |
| - | SUPPL - Chemistry | Formulation changes (new dosage strength) |
Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.
ZONEGRAN FDA Label Details
Indications & Usage
FDA Label (PDF)ZONEGRAN is indicated for the treatment of Epilepsy; Partial Seizures.
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Data Sources
Data sourced from official FDA and NIH databases. Click links to verify on original sources.
How We Calculate These Metrics
Trial Activity Stage
Measures the current development activity pattern based on trial phases, status, and trends. Important: This measures R&D activity, not commercial lifecycle.
Trial statuses: "Active" means recruiting or ongoing. "Completed" means reached planned endpoint. "Terminated" means stopped early—often due to safety, efficacy, or business reasons.
- Growth: High proportion of early-phase trials (Phase 1/2), active development
- Expansion: Significant Phase 3 activity, approaching or pursuing approvals
- Mature: Substantial Phase 4 post-marketing studies
- Stable: Mixed phase distribution, steady development
- Declining: Low active trial ratio, reduced R&D investment