Topiramate

Key facts

• Topiramate (sold as Topamax) is an anticonvulsant used to control seizures and to prevent migraine attacks, and it is sometimes combined with another medicine as part of weight-loss treatment.
• You take it daily, usually starting at a low dose that is increased gradually to limit its effect on thinking and concentration.
• Taken during pregnancy, topiramate raises the risk of cleft lip and palate and low birth weight. It is avoided in pregnancy and in anyone who could become pregnant unless no other option controls the condition, with effective contraception used alongside it.
• Seek urgent care for sudden eye pain and blurred vision, severe flank pain, or confusion with rapid breathing.

What topiramate treats

Topiramate treats several types of seizures in epilepsy, often as an add-on treatment. It also prevents migraine attacks, reducing how often they occur, though it does not relieve a migraine that has already started. It is sometimes combined with another medicine to aid weight loss.

How topiramate works

Topiramate affects several targets in the brain: it blocks sodium channels, boosts the calming effect of GABA, and dampens the excitatory chemical glutamate. Together these actions raise the seizure threshold and reduce the nerve activity thought to trigger migraines.

Before you take it

• Do not take topiramate during pregnancy, or if you could become pregnant, unless your specialist has confirmed there is no safer alternative and you are using effective contraception.
• Tell your prescriber about kidney stones, glaucoma, metabolic acidosis, or a family history of these.
• Topiramate can interact with other anticonvulsants, alcohol, and hormonal contraceptives, which it can make less reliable.
• Drink plenty of water through the day to reduce the risk of kidney stones.

Side effects

Common effects include tingling in the hands or feet, tiredness, difficulty concentrating or finding words, and reduced appetite.

Stop and seek urgent medical care for any of these:

• Sudden eye pain, blurred vision, or vision loss.
• Severe pain in the back or side, or blood in the urine.
• Confusion, rapid breathing, or unusual tiredness.
• Thoughts of self-harm or sudden mood changes.

Safety essentials

• Avoid topiramate in pregnancy: it increases the risk of cleft lip and palate and is used only if no safer anticonvulsant will control your seizures, with effective contraception essential alongside it.
• Cognitive slowing, including trouble concentrating, memory lapses and word-finding difficulty, is common and usually eases if the dose is lowered; tell your prescriber if it affects daily life.
• Drink enough water daily and tell your prescriber about any personal or family history of kidney stones, since topiramate increases their risk.
• Do not stop topiramate abruptly. Stopping suddenly can trigger seizures.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.