Health Library

Zonisamide (By mouth)

Zonisamide (zoe-NIS-a-mide)

Treats partial seizures.

Brand Name(s):

Zonegran, Zonisade

When This Medicine Should Not Be Used:

How to Use This Medicine:

Capsule, Liquid, Tablet

• Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
• Swallow the capsule whole. Do not break, chew, or open it.
• Oral liquid: Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
• This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
• Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Throw away any unused oral liquid 30 days after first opening the bottle.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how zonisamide works. Tell your doctor if you use acetazolamide, dichlorphenamide, digoxin, quinidine, rifampicin, or topiramate.
• Tell your doctor if you are on a ketogenic diet (high-fat, low-carbohydrate diet).
• Do not drink alcohol while you are using this medicine.
• Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

Warnings While Using This Medicine:

• It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant. Use an effective form of birth control during treatment with this medicine and for at least 1 month after the last dose.
• Tell your doctor if you are breastfeeding, or if you have kidney disease, liver disease, breathing or lung problems, bone problems (including osteomalacia, osteopenia, osteoporosis), or a history of depression or metabolic acidosis.
• This medicine may cause the following problems:
  • Serious skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis
  • Drug reaction with eosinophilia and systemic symptoms (DRESS), which may involve multiple organs, including your liver or kidneys
  • Eye or vision problems, including acute myopia, glaucoma
  • Changes in mood or behavior, including suicidal thoughts or behavior
  • Metabolic acidosis (too much acid in your blood)
  • Problems with concentration, attention, memory, thinking, speech, or language
  • Hyperammonemia (too much ammonia in your blood), which may damage the brain and can be life-threatening
  • Kidney stones
• This medicine lowers the number of white blood cells. This weakens your immune system, so you may get infections more easily. Wash your hands often. Avoid people who are sick.
• This medicine may make you dizzy, drowsy, or tired. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
• Talk with your doctor before using this medicine if you plan to have children. Some women who use this medicine have become infertile (unable to have children).
• This medicine may make you sweat less and cause your body temperature to increase. Use caution when you exercise or if you are outside in hot weather.
• Drink extra fluids so you will urinate more often and help prevent kidney problems.
• Do not stop using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely. Your seizures may increase if you stop taking this medicine suddenly.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Blistering, peeling, red skin rash
• Blurred or changes in vision
• Confusion, problems with speech, coordination, concentration, or memory
• Depression, unusual changes in moods or behavior, thoughts of hurting yourself or others
• Fast breathing, loss of appetite, unusual tiredness, fast, pounding, or uneven heartbeat
• Fever, decreased sweating
• Painful or difficult urination, bloody urine, change in how much you urinate, sudden and severe back or stomach pain
• Sore throat, sores or ulcers in the mouth or on the lips, easy bruising
• Swollen, painful, or tender lymph glands in neck, armpit, or groin

If you notice these less serious side effects, talk with your doctor:

• Headache
• Sleepiness, drowsiness, dizziness
• Tiredness
• Trouble sleeping

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Last Updated: 9/6/2024