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About topiramate

Topiramate is a medicine used to treat epilepsy. These are also called anti-epileptic medicines.

It can also be taken to help prevent migraine.

Topiramate works by reducing bursts of electrical activity in your brain and restoring the normal balance of nerve activity.

This medicine is only available on prescription. It comes as tablets, capsules and a liquid you swallow.

If taken during pregnancy, topiramate can increase the risk of birth defects and learning and behaviour problems in your child. Topiramate is not recommended if there's a chance that you could become pregnant.

For women and girls of childbearing age, if there are no other suitable treatments and you do need to take topiramate for epilepsy, your doctor will enrol you on the pregnancy prevention programme.

Important: Topiramate pregnancy prevention programme

The pregnancy prevention programme aims to stop you from accidently becoming pregnant while taking topiramate. It includes:

  • an annual review – you should be reviewed every year by your doctor or nurse, who will assess whether you need to continue taking topiramate or whether it's possible to change your medicine
  • contraception advice – if you are taking topiramate then you must be using reliable contraception, even if you're not currently sexually active

Your doctor or nurse can advise you about reliable contraception. You'll be asked to sign a form to say that you're using contraception and understand the risks of becoming pregnant while taking topiramate.

It's important to get advice from your doctor if:

  • you become pregnant
  • you want to plan a pregnancy

Key facts

  • If you're taking topiramate for epilepsy, it can take 2 to 4 weeks to work fully. If you're taking it to prevent migraines, it can take up to 3 months for it to work fully.
  • You'll usually take topiramate twice a day. You can take it with or without food.
  • Common side effects of topiramate include feeling sleepy, feeling dizzy, diarrhoea and feeling sick. These are usually mild and go away by themselves. Do not drive, cycle or use machinery if you're feeling sleepy or dizzy.
  • If you want to switch from topiramate to another medicine, it's very important to follow your doctor's advice. You'll need to start taking the new one at a low dose and slowly build up the dose while you're still taking topiramate.
  • If you have epilepsy, you're entitled to free prescriptions for all of your medicines, not just your epilepsy ones.
  • If you're pregnant, or there's a chance you could become pregnant, topiramate is not recommended for treating migraine. For epilepsy, your doctor will only prescribe topiramate for you if there are no other suitable treatments.

Page last reviewed: 4 April 2022
Next review due: 4 April 2025