Zonegran Side Effects

Generic name: zonisamide

Medically reviewed by Drugs.com. Last updated on Jan 1, 2025.

Note: This document provides detailed information about Zonegran Side Effects associated with zonisamide. Some dosage forms listed on this page may not apply specifically to the brand name Zonegran.

Applies to zonisamide: oral capsule, oral suspension.

Precautions

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 (the active ingredient contained in Zonegran) 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.

Serious side effects of Zonegran

Along with its needed effects, zonisamide 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 while taking zonisamide:

Other side effects of Zonegran

Some side effects of zonisamide 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:

See also:

For healthcare professionals

Applies to zonisamide: oral capsule, oral suspension.

General adverse events

The most common adverse reactions to this drug are somnolence, dizziness, and anorexia.^[Ref]

Gastrointestinal

• Very common (10% or more): Anorexia (13%)
• Common (1% to 10%): Abdominal pain, nausea, diarrhea, dyspepsia, constipation, dry mouth^[Ref]

Nervous system

• Very common (10% or more): Somnolence (17%), dizziness (13%), headache (10%), ataxia
• Common (1% to 10%): Paresthesia, fatigue, tiredness, bradyphrenia, tremor
• Uncommon (0.1% to 1%): Convulsion
• Very rare (less than 0.01%): Coma, grand mal seizure, myasthenic syndrome, neuroleptic malignant syndrome, status epilepticus
• Postmarketing reports: Restless legs syndrome^[Ref]

Other

• Common (1% to 10%): Speech abnormalities, difficulties in verbal expression, taste perversion^[Ref]

Psychiatric

• Very common (10% or more): Agitation, irritability, confusional state, depression
• Common (1% to 10%): Difficulty concentrating, difficulty with memory, mental slowing, insomnia, anxiety, nervousness, affect lability, psychotic disorder
• Uncommon (0.1% to 1%): Anger, aggression, suicidal ideation, suicide attempt
• Very rare (less than 0.01%): Hallucination, amnesia, mania^[Ref]

Ocular

• Common (1% to 10%): Nystagmus, diplopia^[Ref]

Dermatologic

• Common (1% to 10%): Rash
• Very rare (less than 0.01%): Drug rash with eosinophilia and systemic symptoms, anhidrosis, erythema multiforme, pruritus, Stevens-Johnson syndrome, toxic epidermal necrolysis^[Ref]

Metabolic

• Very common (10% or more): Anorexia
• Common (1% to 10%): Weight loss
• Very rare (less than 0.01%): Metabolic acidosis
• Postmarketing reports: Elevated creatine phosphokinase^[Ref]

Hematologic

• Common (1% to 10%): Ecchymosis
• Very rare (less than 0.01%): Agranulocytosis, aplastic anemia, leukocytosis, leucopenia, lymphadenopathy, pancytopenia, thrombocytopenia^[Ref]

Respiratory

• Common (1% to 10%): Rhinitis
• Uncommon (0.1% to 1%): Pneumonia^[Ref]

Endocrine

• Uncommon (0.1% to 1%): Urinary tract infection
• Postmarketing reports: Acute pancreatitis^[Ref]

Musculoskeletal

• Postmarketing reports: Rhabdomyolysis^[Ref]

Genitourinary

• Uncommon (0.1% to 1%): Urinary tract infection^[Ref]

Hypersensitivity

• Common (1% to 10%): Hypersensitivity
• Very rare (less than 0.01%): Drug induced hypersensitivity syndrome^[Ref]

Immunologic

• Common (1% to 10%): Influenza syndrome^[Ref]

Renal

• Very rare (less than 0.01%): Renal tubular acidosis
• Frequency not reported: Nephrolithiasis, hydronephrosis, renal failure, urine abnormality^[Ref]

Further information

Zonegran side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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