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Zonisamide (Oral)

Generic name: zonisamide [ zoe-NIS-a-mide ]
Brand names: Zonegran, Zonisade
Drug class: Carbonic anhydrase inhibitor anticonvulsants

Medically reviewed by Drugs.com. Last updated on May 11, 2023.

Uses for zonisamide

Zonisamide is used together with other medicines to treat partial-onset seizures (convulsions) in the treatment of epilepsy. It acts on the central nervous system (CNS) to reduce the number and severity of seizures.

This medicine is available only with your doctor's prescription.

Before using zonisamide

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of zonisamide in children younger than 16 years of age. Safety and efficacy have not been established.

Geriatric

Although appropriate studies on the relationship of age to the effects of zonisamide have not been performed in the geriatric population, geriatric-specific problems are not expected to limit the usefulness of zonisamide in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving zonisamide.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper use of zonisamide

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

This medicine comes with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.

You may take the medicine with or without food.

Swallow the capsule whole. Do not break, crush, or chew it.

Measure the oral liquid with a marked measuring spoon, oral syringe, or medicine cup. The average household teaspoon may not hold the right amount of liquid.

Drink extra water every day with this medicine to help prevent kidney stones.

This medicine will be used together with other seizure medicines. Keep using all of your medicines unless your doctor tells you to stop.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Throw away any unused oral liquid 30 days after first opening the bottle.

Detailed Zonisamide dosage information

Precautions while using zonisamide

It is very important that your doctor check your progress at regular visits to see if the medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment with this medicine and for 1 month after the last dose. If you think you have become pregnant while using this medicine, tell your doctor right away.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these side effects, tell your doctor right away.

Check with your doctor right away if you have sudden back pain, abdominal or stomach pain, pain while urinating, or bloody or dark urine. These may be symptoms of kidney stones.

Serious skin reactions (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis) can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness.

This medicine can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. If you can, avoid people with infections. Check with your doctor right away if you think you are getting an infection, or if you have a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.

Zonisamide may cause serious allergic reaction called drug reaction with eosinophilia and systemic symptoms (DRESS), which can be life-threatening and requires immediate medical attention. Check with your doctor right away if you have black, tarry stools, chest pain, chills, cough, fever, painful or difficult urination, sore throat, sores, ulcers, or white spots on the lips or in the mouth, swollen glands, trouble breathing, or unusual bleeding or bruising.

This medicine may make you sweat less, which causes your body temperature to increase. Use extra care not to become overheated during exercise or hot weather while you are taking this medicine. Overheating may result in heat stroke. Also, hot baths or saunas may make you dizzy or faint while you are taking this medicine.

Check with your doctor right away if eye pain or redness, blurred vision, difficulty with reading, or any other change in vision occurs during or after treatment. These could be symptoms of serious eye or vision problems (eg, acute myopia, secondary angle closure glaucoma). Your doctor may want your eyes be checked by an ophthalmologist (eye doctor).

Call your doctor right away if you have fast breathing, loss of appetite, fast, pounding, or uneven heartbeats, or unusual tiredness or weakness. These may be symptoms of a condition called metabolic acidosis.

This medicine may cause slow growth. If your child is using this medicine, the doctor will need to keep track of your child's height and weight to make sure that your child is growing properly.

Zonisamide may cause hyperammonemia (too much ammonia in the blood), which may damage the brain and can be life-threatening. Check with your doctor right away if you have nausea or vomiting that continues, an increase in the frequency of seizures, loss of appetite, swelling of the face, tiredness and weakness, or yellow eyes or skin.

Do not stop taking zonisamide without first checking with your doctor. Stopping the medicine suddenly may cause your seizures to return or to occur more often. Your doctor may want you to gradually reduce the amount of medicine you are taking before stopping it completely.

This medicine may cause some people to become dizzy, drowsy, or less alert than normal. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines, medicine for allergies or colds, sedatives, tranquilizers, sleeping medicine, prescription pain medicine, narcotics, medicine for seizures, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor or dentist before taking any of the above while you are taking this medicine.

Some women who use this medicine have become infertile (unable to have children). Talk with your doctor before using this medicine if you plan to have children.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines, and herbal or vitamin supplements.

Side Effects of zonisamide

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Less common

Rare

Incidence not known

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Zonisamide side effects (more detail)

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Anticonvulsant

Chemical Class: Sulfonamide

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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