What is Topamax?

Topamax is a medication that is used to treat seizures in adults and children. It is also used to prevent migraines. Topamax may be used alone or with other seizure medications.

Topamax is available as a generic drug.


What are the side effects of Topamax?

The most common side effects of Topamax include:







weight loss

trouble thinking or concentrating

rare side effects include:




If these persist or worsen, notify your doctor. immediately

Rare but SERIOUS side effects include:

uncontrollable eye movements

muscle weakness

trouble walking

kidney stones

If you experience any of these, call your doctor IMMEDIATELY.


Topamax is taken by mouth, typically 2 or 3 times a day.

Your doctor will start you on a low dose of Topamax and gradually increase your dose over time.

Take Topamax exactly as prescribed by your doctor. Do not take more or less of it or take it more often than prescribed by your doctor.

If you miss a dose of Topamax, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take two doses at the same time.

Store Topamax at room temperature away from light and moisture.

Mechanism of Action

Topamax works by decreasing nerve activity in the brain. This effect is thought to be due to its actions on several neurotransmitters, including GABA, glutamate, and serotonin.


You should not take Topamax if you are allergic to it.

Topamax may cause drowsiness or dizziness. Do not drive or operate heavy machinery until you know how Topamax affects you.

Do not drink alcohol while taking Topamax. Alcohol can increase the risk of seizures.

Pregnancy and Topamax

Topamax is a category C pregnancy drug. That means two things:

Research in animals has shown adverse effects to the fetus when the mother takes the drug. There are no adequate studies in humans, however.

Women who are pregnant or who may become pregnant should not take Topamax.


The pharmacokinetics of Topamax have not been extensively studied.

Topamax is thought to be well-absorbed from the gastrointestinal tract. It is metabolized in the liver and has a half-life of 20-60 hours.

Elimination of Topamax is primarily through the kidneys.

Long-term effects

There is no information on the long-term effects of Topamax.

If you take Topamax for a long period of time, your doctor will probably want to check your weight, blood pressure, and kidney function regularly.


Topamax may interact with other drugs.

Tell your doctor all medications and supplements you use.

Topamax may interact with:



divalproex sodium





tricyclic antidepressants

This list is not complete and other drugs may interact with Topamax. Tell your doctor about all your prescriptions and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.


Symptoms of overdose may include:



slurred speech

problems with coordination

double vision

poor judgment



Other drugs may be available that can treat your condition. Talk with your doctor about the risks and benefits of taking Topamax.

How is it supplied?

Topamax is available as oral tablets in 25 mg, 50 mg, 100 mg, and 200 mg strengths.

It is also available as an oral sprinkle capsule in 15 mg and 25 mg sizes.

How long does it stay in the body?

The half-life of a drug is the time it takes for the concentration of the drug in your body to be reduced by half.

Topamax has a half-life of 20-60 hours. That means that it takes 20-60 hours for the concentration of Topamax in your body to be reduced by half.

After five elimination half-lives, 97.5% of the drug will have been eliminated from your body. Therefore, it would take approximately 100-300 hours (4-12 days) for Topamax to be completely eliminated from your body.