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How long does it take for Topamax to start working?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on June 19, 2023.

Official answer

  • It may take 8 to 12 weeks for you to see the full effect of Topamax (topiramate) on your migraine headaches. In clinical studies, some people had fewer headaches after 4 weeks of treatment. Treatment with Topamax for migraine prevention is taken daily and is usually started slowly at lower doses.
  • In the treatment of epilepsy (seizures), Topamax is also started slowly and the dose is increased over a 6-week period for adults and children 10 years and older. In children 2 to 9 years of age, the dose is based on weight and may be slowly increased from 5 to 7 weeks.

Your doctor will prescribe a lower dose of Topamax at the beginning. Your dose will be slowly increased to the amount needed to control your seizures or migraine and to help limit side effects.

Your dose is not usually increased more than once per week. Your dose will be gradually increased until you have an effective response, reach a maximum allowed dose, or have intolerable side effects.

Related: Topamax dosage (in more detail)

Take Topamax every day as directed by your doctor. Do not change your dose without speaking to your doctor first. Before stopping, it is recommended that the dose be reduced gradually.

When taken twice a day, the medicine is usually taken in the morning and evening. At the beginning of treatment for some uses, your dose may be taken only at night for a short while.

Why is Topamax prescribed?

Topamax (topiramate), classified as an anticonvulsant medicine, is an oral medication taken alone or with other medicines to control certain types of seizures due to epilepsy and for the prevention of migraine headaches.

It is approved by the FDA:

  • to treat certain types of seizures (partial-onset seizures and primary generalized tonic-clonic seizures) in adults and children 2 years and olde
  • for use with other medicines to treat certain types of seizures (partial-onset seizures, primary generalized tonic-clonic seizures, and seizures associated with Lennox-Gastaut syndrome) in adults and children 2 years and older
  • to prevent migraine headaches in adults and adolescents 12 years and older.

Topamax may cause drowsiness, dizziness, blurred vision or impair your thinking and reaction time. Avoid driving or operating machinery until you know how this medicine will affect you.

You can take Topamax with or without food. The tablets are bitter so do not break, crush or split them. Do not drink alcohol while taking Topamax as it may worsen side effects like drowsiness or dizziness. Drink plenty of fluids during the day to help prevent kidney stones.

Learn more: View Topamax side effects, warnings and drug interactions (in more detail)

This is not all the information you need to know about Topamax (topiramate) for safe and effective use and does not take the place of talking to your doctor about your treatment. Review the full patient information for Topamax and discuss this information and any questions you have with your doctor or other health care provider.

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