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Topiramate drug information

Patient information A-Z

Who is this information for?

  • Patients
  • Staff

Drug / brand names

  • Topiramate
  • Topamax


Topiramate is available as 25mg, 50mg, 100mg and 200mg tablets. Tablets should ideally be swallowed whole with plenty of water. For patients with an enteral tube the tablets may be dispersed within water immediately prior to administration to aid administration.

15mg, 25mg and 50mg hard capsules containing beads of the drug are also available. These can be opened and the contents sprinkled on food. The beads must be swallowed whole with the food and not chewed. Note that administration of the beads through an enteral feeding tube does not work well, as the beads readily stick to the tubing and block the tube.


Topiramate is an antiepileptic drug used to reduce seizure frequency or severity. It is used alone or alongside other antiepileptic medication for the treatment of generalised (tonic clonic) seizures or focal (partial) seizures with or without progression to generalised seizures.

Topiramate can be considered, under specialist supervision, for the following unlicensed indications:

  • Absence seizures
  • Tonic and atonic seizures
  • Myoclonic seizures
  • Lennox-gastaut syndrome
  • Dravet syndrome

Topiramate is also used to help prevent migraine (however, it must not be used for this indication within pregnancy).

Side effects

(This list is not exhaustive, please refer to product literature for full list)

Side effects can be more likely as the dose of topiramate is increased and may improve if the dose is reduced again.

Side effects sometimes occur temporarily when the medication is started or as the dose is increased. If you are also taking other anti-epileptic medication, sometimes reducing the doses of these, rather than the topiramate dose may alleviate these side effects. Always consult your doctor or epilepsy specialist nurse for advice on dose alterations, dose changes should only be made on medical advice.

In practice, side effects usually settle within eight weeks of starting medication.

Common side effects:

  • Sleepiness and fatigue
  • Nausea and vomiting
  • Bowel problems such as diarrhoea or constipation
  • Dizziness
  • Double or blurred vision
  • Tingling of the skin, taste touch and sensation changes
  • Cramps and aches
  • Mood change, depression and confusion, which may occasionally be severe. All antiepileptic medication can cause feelings of depression, or severe mood changes. If you experience any of these please contact your specialist.
  • Reduced appetite leading to weight loss
  • Anaemia
  • Speech or word finding difficulty and difficulty concentrating
  • Rash
  • Topiramate may trigger development of kidney stones. You should not take it if you have a history of stones. If you develop flank pain contact your GP.

Rare side effects:

  • Glaucoma – report any pain in the eye, changes to vision or unusual excessive redness to the eye as soon as possible. Topiramate should not be taken by patients with a history of glaucoma.
  • Reduced or changes to hearing
  • Reduced blood pressure or slowing of the heart rate
  • Abdominal pain
  • Topiramate can reduce sweating; if you are exercising or in a hot environment, ensure that you drink plenty of fluids. Very rarely medical help is needed if body temperature rises.

In the event of any of these side effects, contact the epilepsy nurse (contact details are at the end of the leaflet), or your GP.


At doses above 200mg daily topiramate is known to reduce the amount of the oral contraceptive pill in your body so that a higher dose pill is required. Contraception may still remain slightly less effective, especially if you notice any breakthrough bleeding between periods.

You should consider additional barrier methods, such as condoms, until this problem is corrected. Topiramate does not affect the three month contraceptive injection or the hormone coil (Mirena).

Pregnancy and breastfeeding

When taking any anti-epileptic drug, you should ask to see your specialist and discuss the best preparations and doses before you conceive. Once you are already pregnant it is too late to make these changes. There is data to show topiramate use during pregnancy is associated with increased risk of major congenital malformations. This risk is considered to be dose dependent.

There is an increased risk of intrauterine growth restriction (low birth weight). The risks to your baby from topiramate are not fully understood; it has caused problems in animal studies. The relevance to humans is unclear; the manufacturer does not endorse use in pregnancy unless recommended by your specialist. We recommend you take folic acid 5mg daily twelve weeks prior to conception until the end of week 12 of pregnancy.

Topiramate is found in breast milk, and the drug manufacturer advises to avoid use when breastfeeding if possible; specialist advice should be sought.

Drug interactions

Pain medications such as paracetamol and aspirin can be taken with topiramate. Antibiotics can be taken with topiramate. Topiramate is known to affect other medication and may itself be affected by other medication. Always remind your doctor or pharmacist that you take topiramate when new medication is discussed or started.

Other useful information

  • You can take topiramate at the same time as you take other medication and with or without food. Do not stop taking your medication suddenly and without consultation with your doctor.
  • Keep a record of your seizures when you start any new medication. This will help to determine future dose alterations.
  • Store topiramate below 30°C and in the packaging that it comes in.
  • If you miss a dose, take it as soon as you remember but do not take two doses at the same time or within a six hour period.
  • Note: topiramate capsules contain sucrose.

Contact details

If you have any questions or concerns, please contact the epilepsy nurse specialist on 01223 217992.

This information is not exhaustive. Please refer to the patient information leaflet prepared by the manufacturer of your drug which can be found in the medicine packaging.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151