Medically reviewed by Drugs.com. Last updated on Apr 27, 2022.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Anticonvulsant
Chemical Class: Sulfonamide
Uses for zonisamide
Zonisamide is used together with other medicines to control partial seizures (convulsions) in the treatment of epilepsy. Zonisamide is an anticonvulsant that works in the brain to stop seizures.
Zonisamide 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 zonisamide, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to zonisamide 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.
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.
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.
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 zonisamide, 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 zonisamide 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 zonisamide 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 zonisamide 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.
- Aminolevulinic Acid
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 zonisamide 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 zonisamide, 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 zonisamide. Make sure you tell your doctor if you have any other medical problems, especially:
- Allergy to sulfa drugs, history of—Should not be used in patients with this condition.
- Blood or bone marrow problems (eg, agranulocytosis, aplastic anemia) or
- Bone problems (eg, osteomalacia, osteopenia, osteoporosis) or
- Depression, history of or
- Mental illness (eg, psychosis) or
- Metabolic acidosis (high acid in the blood)—Use with caution. May make these conditions worse.
- Breathing or lung problems, severe or
- Diarrhea or
- Ketogenic diet, history of—Use with caution. May cause side effects to become worse.
- Kidney disease or
- Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper use of zonisamide
Take zonisamide 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.
Zonisamide comes with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.
Take the capsule with or without food. Swallow the capsule whole. Do not break, crush, or chew it.
Drink extra water every day with zonisamide to help prevent kidney stones.
Zonisamide will be used together with other seizure medicines. Keep using all of your medicines unless your doctor tells you to stop.
The dose of zonisamide 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 zonisamide. 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.
- For oral dosage form (capsules):
- For seizures:
- Adults and children 16 years and older—At first, 100 milligrams (mg) once a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 400 mg per day.
- Children younger than 16 years—Use and dose must be determined by the doctor.
- For seizures:
If you miss a dose of zonisamide, 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.
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.
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.
Zonisamide 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 can occur with zonisamide. 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 skin lesions, often with a purple center, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness.
Zonisamide 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 reactions called drug reaction with eosinophilia and systemic symptoms (DRESS) or multiorgan hypersensitivity, which may damage the liver, kidney, blood, heart, or muscles. Check with your doctor right away if you have a fever, dark urine, headache, rash, stomach pain, swelling of the face, feet, or lower legs, swollen, painful, or tender lymph glands in the neck, armpit, or groin, trouble breathing, unusual tiredness, or yellow eyes or skin.
Zonisamide 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 zonisamide. Overheating may result in heat stroke. Also, hot baths or saunas may make you dizzy or faint while you are taking zonisamide.
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.
Zonisamide may cause slow growth. If your child is using zonisamide, 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.
Zonisamide may cause some people to become dizzy, drowsy, or less alert than normal. Make sure you know how you react to zonisamide before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.
Zonisamide 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 zonisamide.
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.
Zonisamide side effects
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:
- double vision
- feeling sad or empty
- lack of appetite
- loss of interest or pleasure
- mood or mental changes
- shakiness or unsteady walking
- trouble with concentrating
- trouble with sleeping
- large, flat blue or purplish patches on the skin
Incidence not known
- Blurred vision
- change in near or distance vision
- difficulty in focusing eyes
- eye pain
- increase in frequency of seizures
- swelling of the face
- yellow eyes or skin
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:
- Abdominal or stomach pain
- difficulty with memory
- double vision
- loss of appetite
- unusual drowsiness
- unusual tiredness or weakness
- Aching muscles or joints
- acid or sour stomach
- bad, unusual, or unpleasant taste in the mouth
- change in taste
- difficulty with speaking
- difficulty with thinking
- dry mouth
- general ill feeling
- mental slowness
- runny or stuffy nose
- tingling, burning, or prickly feelings on the skin
- uncontrolled, back and forth, or rolling eye movements
- weight loss
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.
More about zonisamide
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- Drug class: carbonic anhydrase inhibitor anticonvulsants
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