Prescription medicine
Zonisamide Brand names: Zonegran
Zonisamide (Zonegran) is a prescription medicine with an FDA approval on record since 2000. FDA's NDC Directory lists it from 20 generic labelers, and pharmacies paid $0.106 per zonisamide 100 mg capsule in the October 7, 2026 NADAC survey; its other strengths are brand-only, $2.75 per mL (Zonisade 100 mg/5 mL oral suspension).
- Generic listed
Check it at the source: the zonisamide FDA label on DailyMed (effective June 4, 2026, Sun Pharmaceutical Industries, Inc.); the NDA 20789 record on Drugs@FDA; every zonisamide label on DailyMed.
Highlights of the record
FDA label of June 4, 2026; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
Used for
From the label: indications and usageZonisamide is indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.
Forms and strengths
- 25 mg
- 50 mg
- 100 mg
- 100 mg/5ml
Capsule; suspension.
On the market
- Earliest approval on file
- March 27, 2000 Zonegran, Advanz Pharma; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 19 first December 22, 2005; 7 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 22 of which 20 under generic applications, 2 under brand applications, repackagers included
- Last listed patent
- August 18, 2038 Zonisade oral suspension; not a generic launch date
Supply and safety
- Pharmacy cost (NADAC)
- $0.106 per capsule Zonisamide 100 mg capsule
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- 11 since 2013 0 Class I among all firms' recalls; latest May 13, 2022; 1 more by firms not listed as its makers
- FAERS reports
- 10,560 through July 30, 2026
What is zonisamide used for?
From the label: indications and usageZonisamide is indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.
Conditions named in the indications of zonisamide's FDA labels, with every medicine labeled for each:
From other zonisamide labelsSeizures and epilepsy: INDICATIONS AND USAGE Zonisamide is indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.
FDA pharmacologic class: Anti-epileptic Agent.
Source: FDA drug label (Zonisamide), Sun Pharmaceutical Industries, Inc., effective June 4, 2026 (SPL set 3164d438-90bf-420a-9a56-5498b987f91c), via openFDA; the full label on DailyMed
What does the patient leaflet for zonisamide say first?
The FDA-approved Medication Guide or Patient Information that comes with the medicine, in its own words.
From the patient leaflet: What is the most important information I should know about Zonisamide Capsules?Zonisamide capsules may cause serious side effects, including: Serious skin rash that can cause death. Serious allergic reactions that may affect different parts of the body. Less sweating and increase in your body temperature (fever). Serious eye problems Suicidal thoughts or actions in some people. Increased level of acid in your blood (metabolic acidosis). Problems with your concentration, attention, memory, thinking, speech, or language. Blood cell changes such as reduced red and white blood cell counts. These serious side effects are described below. 1. Zonisamide capsules may cause a serious skin rash that can cause death. These serious skin reactions are more likely to happen when you begin taking zonisamide capsules within the first 4 months of treatment but may occur at later times. 2. Zonisamide capsules can cause other types of allergic reactions or serious problems that may affect different parts of the body such as your liver, kidneys, heart, or blood cells. You may or may not have a rash with these types of reactions. These reactions can be very serious and can cause death. Call your health care provider right away if you have: fever severe muscle pain rash swollen lymph glands swelling of your face unusual bruising or bleeding weakness, fatigue yellowing of your skin or the white part of your eyes 3. Zonisamide capsules may cause you to sweat less and to increase your body temperature (fever). You may need to be hospitalized for this. You should watch for decreased sweating and fever, especially when it is hot and especially in children taking zonisamide capsules. Call your health care provider right away if you have: high fever, recurring fever, or long lasting fever less sweat than normal 4. Zonisamide capsules may cause eye problems. […]
From the patient leaflet: What should I avoid while taking Zonisamide Capsules?Do not drink alcohol or take other drugs that make you sleepy or dizzy while taking zonisamide capsules until you talk to your health care provider. Zonisamide capsules taken with alcohol or drugs that cause sleepiness or dizziness may make your sleepiness or dizziness worse. Do not drive, operate heavy machinery, or do other dangerous activities until you know how zonisamide capsules affect you. Zonisamide capsules can slow your thinking and motor skills.
From the patient leaflet: How should I store Zonisamide Capsules?Store zonisamide capsules at 25°C (77°F); excursions permitted to 15°-30°C (59°-86°F) Keep zonisamide capsules dry and away from light Keep zonisamide capsules and all medicines out of the reach of children. General Information about the safe and effective use of Zonisamide Capsules Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use zonisamide capsules for a condition for which it was not prescribed. Do not give zonisamide capsules to other people, even if they have the same symptoms that you have. It may harm them. You can ask your pharmacist or healthcare provider for information about zonisamide capsules that is written for health professionals.
Source: FDA drug label (Zonisamide), Sun Pharmaceutical Industries, Inc., effective June 4, 2026 (SPL set 3164d438-90bf-420a-9a56-5498b987f91c), via openFDA; the full label on DailyMed
Is there a generic for zonisamide (Zonegran)?
The FDA approved the first generic zonisamide on December 22, 2005. 19 generic applications are approved; 7 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists zonisamide from 20 labelers under a generic (ANDA) application and from 2 brand labelers. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
The Orange Book lists no patent for Zonegran capsules; a patent listed only for Zonisade oral suspension runs to August 18, 2038. A patent or exclusivity date is not the date a generic goes on sale: court cases and settlements move it either way.
- 2000 earliest approval on file
- 2005 first generic approved
- 2038 last listed patent
- red ticks recalls
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for zonisamide (Zonegran)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $0.106 per Zonisamide 100 mg capsule, down 1% from $0.107 on October 8, 2025. Prices per unit in the table differ many-fold by strength, form and brand, so compare like with like. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Zonisamide 100 mg capsule (generic)
- Zonisade 100 mg/5 mL oral suspension (brand)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Zonisamide 100 mg capsule | Generic | $0.106 per capsule | $3.19 | -1% |
| Zonisamide 25 mg capsule | Generic | $0.0655 per capsule | $1.96 | +1% |
| Zonisamide 50 mg capsule | Generic | $0.0955 per capsule | $2.87 | -3% |
| Zonisade 100 mg/5 mL oral suspension | Brand | $2.75 per mL | n/a | +3% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
Has zonisamide been recalled?
The FDA's Enforcement Report lists 12 recalls naming zonisamide since 2013: 0 Class I (the most serious), 12 Class II, 0 Class III; 0 still ongoing. 1 of them is by a firm that FDA's NDC Directory does not list as a maker of zonisamide and that holds no application for it in Drugs@FDA, such as compounding pharmacies or bulk-ingredient suppliers; the recall notice names the product recalled. A recall names products and lots, not every product of the medicine.
| Started | Class | Company | Reason |
|---|---|---|---|
| May 13, 2022 | Class II | Direct Rx | CGMP Deviations: Gaps in the quality system in the Quality Control microbiology laboratory. |
| April 25, 2022 | Class II | Glenmark Pharmaceuticals Inc., USA | cGMP deviations |
| September 14, 2021 | Class II | Direct Rx | CGMP deviations: Gaps in the quality system in the Quality Control microbiology laboratory. |
| August 27, 2021 | Class II | Glenmark Pharmaceuticals Inc., USA | CGMP Deviations |
| June 1, 2015 | Class II | American Health Packaging | CGMP Deviations: Firm did not adequately investigate customer complaints. |
| April 22, 2015 | Class II | Wockhardt Usa Inc. | CGMP Deviations: Firm did not adequately investigate customer complaints. |
| July 2, 2013 | Class II | Aidapak Services, LLC not a listed maker | Labeling: Label Mixup; ZONISAMIDE Capsule, 100 mg may be potentially mislabeled as PHYTONADIONE, Tablet, 5 mg, NDC 25010040515, Pedigree: W003737, EXP … |
Source: FDA Enforcement Report (drug recalls) via openFDA, through October 8, 2026
What does the zonisamide label say about other medicines?
The zonisamide label names 5 other medicines in its interaction, contraindication or warning sections. The labels of 14 other medicines name zonisamide. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Acetazolamide | drug interactions | Other Carbonic Anhydrase Inhibitors: Concomitant use of ZONEGRAN, a carbonic anhydrase inhibitor, with any other carbonic anhydrase inhibitor (e.g., topiramate, acetazolamide or dichlorphenamide), may increase the severity of metabolic acidosis and may also increase the risk of kidney stone formation or the risk of … |
| Dichlorphenamide | drug interactions | Other Carbonic Anhydrase Inhibitors: Concomitant use of ZONEGRAN, a carbonic anhydrase inhibitor, with any other carbonic anhydrase inhibitor (e.g., topiramate, acetazolamide or dichlorphenamide), may increase the severity of metabolic acidosis and may also increase the risk of kidney stone formation or the risk of … |
| Divalproex | warnings | The risks of hyperammonemia and various manifestations of encephalopathy may be increased in patients treated with zonisamide and concomitantly taking other medications that can cause hyperammonemia, including valproic acid or topiramate (see PRECAUTIONS ). |
| Topiramate | warnings | The risks of hyperammonemia and various manifestations of encephalopathy may be increased in patients treated with zonisamide and concomitantly taking other medications that can cause hyperammonemia, including valproic acid or topiramate (see PRECAUTIONS ). |
| Valproic acid | warnings | The risks of hyperammonemia and various manifestations of encephalopathy may be increased in patients treated with zonisamide and concomitantly taking other medications that can cause hyperammonemia, including valproic acid or topiramate (see PRECAUTIONS ). |
Other labels that name zonisamide
Source: FDA drug label (Zonisamide), Sun Pharmaceutical Industries, Inc., effective June 4, 2026 (SPL set 3164d438-90bf-420a-9a56-5498b987f91c), via openFDA; the full label on DailyMed
What do FAERS reports show for zonisamide?
The FDA Adverse Event Reporting System holds 10,560 reports that list zonisamide among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 677 are coded as a death and 3,245 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as zonisamide?
20 other medicines are given the same way (oral) and in the same FDA class as zonisamide or labeled mainly for the same use (seizures and epilepsy), the same class first. Seizures and epilepsy lists all 27 medicines labeled for it, by any route. The first 8 are below. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (oral) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Gabapentin | Seizures and epilepsy | 87 labelers | $0.0218 per capsule 100 mg capsule | No current entry |
| Lamotrigine | Seizures and epilepsy | 50 labelers | $0.0268 per tablet 25 mg tablet | A presentation being discontinued |
| Divalproex | Seizures and epilepsy | 44 labelers | $0.194 per tablet 500 mg tablet | No current entry |
| Oxcarbazepine | Seizures and epilepsy | 43 labelers | $0.167 per tablet 300 mg tablet | No current entry |
| Valproic acid | Seizures and epilepsy | 19 labelers | $0.243 per capsule 250 mg capsule | Listed; available |
| Phenytoin | Seizures and epilepsy | 23 labelers | $0.145 per capsule 100 mg capsule | No current entry |
| Primidone | Seizures and epilepsy | 21 labelers | $0.0914 per tablet 50 mg tablet | No current entry |
| Felbamate | Seizures and epilepsy | 9 labelers | $1.00 per tablet 600 mg tablet | No current entry |
Every medicine labeled for the same conditions as zonisamide
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
How does zonisamide compare with medicines for the same use?
6 side-by-side pages set zonisamide beside a medicine whose label shares a use: approvals, generics, pharmacy cost, warnings and supply.
What next?
- Alternatives to zonisamide
- 20 medicines for the same use
- Other anti-seizure medicines
- the pharmacologic class, with prices and generics
- Zonisamide side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other