Zonegran (Zonisamide) an antiepileptic medicine. Zonegran is used to treat adults who are already taking other antiepileptic medicines but are still experiencing seizures that affect one part of the brain (partial seizure).

Why have I been prescribed Zonegran?

  • Zonegran (Zonisamide) an antiepileptic medicine.
  • Zonegran is used to treat adults who are already taking other antiepileptic medicines but are still experiencing seizures that affect one part of the brain (partial seizure), which may or may not be followed by a seizure affecting all of the brain (secondary generalisation).

How does it work?

Zonegran works by keeping the brain’s “overexcitable” nerve cells under control, thereby reducing the frequency of such seizures.

When and how do I take it?

Zonegran capsules must be swallowed whole with water.

  • Do not chew the capsules.
  • Zonegran can be taken once or twice daily, as instructed by your doctor.
  • It you take Zonegran twice a day, take half the daily dose in the morning and half in the evening.

What’s the dose?

The starting dose is 50 mg daily taken in two equal doses of 25 mg.

  • This may be increased by up to 100 mg at intervals of one to two weeks.
  • The usual daily dose is between 300 mg and 500 mg.
  • Some people respond to lower doses. The dose may be increased more slowly if you experience side effects, are elderly or if you suffer from kidney or liver problems.

Could it interact with other tablets?

Please tell your doctor or pharmacist if you are taking, or have recently taken, any other medicines, including medicines obtained without a prescription.

  • Zonegran should be used carefully when taken with medicines that can cause kidney stones, like topiramate.
  • Zonegran could possibly increase your blood levels of medicines like digoxin and quinidine, and so a reduction in their dose may be required.
  • Other medicines like phenytoin, carbamazepine, phenobarbitone and rifampicin can decrease your blood levels of Zonegran, which may require an adjustment of your dose of Zonegran.

Herbal preparations should only be taken after discussing with your doctor.

What are the possible risks or side-effects?

Like all medicines, Zonegran can cause side effects, although not everybody gets them.

Zonegran belongs to a group of medicines (sulphonamides) that can cause severe allergic reactions, severe skin rashes, and blood disorders, which very rarely can be fatal.

Contact your doctor immediately if you:

  • have difficulty breathing, a swollen face, lips or tongue, or a severe skin rash as these symptoms may indicate that you are having a severe allergic reaction.
  • have thoughts of harming or killing yourself. A small number of people being treated with antiepileptics such as Zonegran have had thoughts of harming or killing themselves.
  • have pain in your muscles or a feeling of weakness, as this may be a sign of abnormal muscle breakdown which can lead to kidney problems.
  • get a sudden pain in your back or stomach, have pain on urinating (passing water) or notice blood in your urine, as this may be a sign of kidney stones.

Contact your doctor as soon as possible if you:

  • have an unexplained skin rash, as this could develop into a more severe skin rash or skin peeling.
  • feel unusually tired or feverish, have a sore throat, swollen glands, or find that you bruise more easily, as this may mean you have a blood disorder.
  • have headaches, drowsiness, shortness of breath and loss of appetite as this could be a sign that your blood level of bicarbonate is too low, which your doctor may need to monitor or treat. Your doctor may decide that you should stop using Zonegran.

The most common side effects of Zonegran are mild. They occur during the first month of treatment and usually decrease with continued treatment.

Very common side effects (affects more than 1 user in 10)

  • agitation, irritability, confusion, depression
  • poor muscle coordination, dizziness, poor memory, sleepiness, double vision
  • loss of appetite, decreased blood levels of bicarbonate (a substance that prevents your blood from becoming acidic)

Common side effects (affects 1 to 10 users in 100)

  • difficulty sleeping, strange or unusual thoughts, feeling anxious or emotional.
  • slowed thoughts, loss of concentration, speech abnormalities, abnormal skin sensation (pins and needles), tremor, involuntary movement of the eyes.
  • kidney stones.
  • skin rashes, allergic reactions, fever, tiredness, flu-like symptoms.
  • ecchymosis (a small bruise caused by blood leaking from broken blood vessels in the skin).
  • loss of weight, nausea, indigestion, stomach pains, diarrhoea (loose stools), constipation.

Can I drink alcohol while taking it?

  • There are no known interactions between alcohol and Zonegran.
  • Always check with your pharmacist or doctor first though as other medicines you may be taking may affect this.

What if I’m pregnant/breastfeeding?

  • If you are a woman of childbearing age you must use adequate contraception while taking and for one month after stopping Zonegran.
  • Tell your doctor immediately if you might be, or are pregnant, or are planning to get pregnant.
  • You must only take Zonegran during your pregnancy if your doctor tells you to.
  • Research has shown an increased risk of birth defects in children of women taking anti-epileptic medicines.
  • Do not breastfeed whilst taking, or for one month after stopping Zonegran.


If you have any more questions please ask your Pharmacist.

Remember to keep all medicines out of reach of children
Please Note:
We have made every effort to ensure that the content of this information sheet is correct at time of publish, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.



Health Reference: Epilepsy