Meds & supplements › Zonisamide
Medicine · Anti-epileptic Agent
Zonisamide capsules are indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.
Selected manufacturer label information, organised into consistent sections by Sofidex. Read the full label at DailyMed ↗
Zonisamide is a prescription medicine that is used with other medicines to treat partial seizures in adults.
It is not known if zonisamide capsules is safe or effective in children under 16 years of age.
Do not take zonisamide capsules:
Do not take zonisamide capsules if you are allergic to medicines that contain sulfa.
Before taking zonisamide capsules, tell your healthcare provider about all your medical conditions, including if you:
Tell your healthcare provider if you:
You and your healthcare provider should decide if you should take zonisamide capsules while you are pregnant.
If you become pregnant while taking zonisamide capsules, talk to your healthcare provider about registering with the North American Antiepileptic Drug Pregnancy Registry. You can enroll in this registry by calling 1-888-233-2334. The purpose of this registry is to collect information about the safety of antiepileptic drugs during pregnancy.
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins or herbal supplements.
Zonisamide may cause serious side effects, including:
These serious side effects are described below.
1. Zonisamide may cause a serious skin rash that can cause death. These serious skin reactions are more likely to happen when you begin taking zonisamide within the first 4 months of treatment but may occur at later times.
2. Zonisamide 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:
3. Zonisamide 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.
Call your health care provider right away if you have:
4. Zonisamide may cause eye problems. Serious eye problems include:
These eye problems can lead to permanent loss of vision if not treated.
Call your healthcare provider right away if you have any new eye symptoms, including any eye pain or redness or any new problems with your vision.
5. Like other antiepileptic drugs, zonisamide may cause suicidal thoughts or actions in a very small number of people, about 1 in 500.
Call a healthcare provider right away if you have any of these symptoms, especially if they are new, worse, or worry you:
Zonisamide capsules can cause serious side effects.
Other serious side effects include:
The most common side effects of zonisamide capsules include:
Side effects can happen at any time, but are more likely to happen during the first several weeks after starting zonisamide capsules.
These are not all of the possible side effects of zonisamide capsules.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
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.
Please address medical inquiries to, [email protected] orTel.: 1-888-304-5011.
Call your healthcare provider between visits as needed, especially if you are worried about symptoms.
Do not stop zonisamide without first talking to a healthcare provider.
Stopping zonisamide capsules suddenly can cause serious problems. Stopping a seizure medicine suddenly in a patient who has epilepsy can cause seizures that will not stop (status epilepticus).
6. Zonisamide capsules can increase the level of acid in your blood (metabolic acidosis). If left untreated, metabolic acidosis can cause brittle or soft bones (osteoporosis, osteomalacia, osteopenia), kidney stones and can slow the rate of growth in children. Metabolic acidosis can happen with or without symptoms.
Sometimes people with metabolic acidosis will:
Your healthcare provider should do a blood test to measure the level of acid in your blood before and during your
treatment with zonisamide.
7. Zonisamide capsules may cause problems with your concentration, attention, memory, thinking, speech, or language.
8. Zonisamide capsules can cause blood cell changes such as reduced red and white blood cell counts. Call your healthcare provider if you develop fever, sore throat, sores in your mouth, or unusual bruising.
Zonisamide capsules can have other serious side effects. For more information ask your healthcare provider or pharmacist. Tell your healthcare provider if you have any side effect that bothers you. Be sure to read the section titled "What are the possible side effects of zonisamide capsules?"
sofidex [Internet]. Daloreum; c2026. Zonisamide; [reviewed 2026 Aug 2; cited 2026 Nov 10]. Available from: https://sofidex.com/patients/medicines/zonisamide
sofidex. (2026, August 2). Zonisamide. Daloreum. Retrieved November 10, 2026, from https://sofidex.com/patients/medicines/zonisamide
Zonisamide. sofidex. Reviewed August 2, 2026. Accessed November 10, 2026. https://sofidex.com/patients/medicines/zonisamide
The cited date is today’s, because a citation records when you read the page. The reviewed date is when a clinician last checked it.