OverviewDosageSide EffectsInteractionsHalf-Life

Topamax was the 89th most commonly prescribed drug in the United States in 2017. In that year alone, there were over 8,648,513 prescriptions. Considering how popular this drug is right now, it pays to know a little bit more about this medication, including how long Topamax stays in your system.

Basic Information

Mean effective half-life: 21 hours (different for people of all ages)

Time to steady-state: 4 days

Topamax has an oral bioavailability of roughly 80 percent in tablet form. This oral bioavailability does not change when the medication is taken with food. Roughly 70 percent of this medication is eliminated in an unchanged form in urine. It is also not metabolized extensively. Researchers have found six metabolites in humans, but none of these metabolites make up more than 5 percent of one Topamax dose. The oral plasma clearance is around 20 to 30 mL/min for adults.


What is the half-life of Topamax?

Topamax has a half-life of 21 hours, but it is different for people of all ages.

How long does Topamax stay in your system?

Topamax may stay in your system for a few days or several days depending on certain factors, such as the dosage you take and your metabolism. Since it is mainly excreted through urine, it may appear on drug tests taken before this medication clears your system. It is unlikely to show up on other types of drug tests, such as blood/serum/plasma tests or hair tests.

How do you taper off Topamax?

Individuals should gradually taper off Topamax in order to prevent severe adverse effects from occurring, such as seizures or migraine headaches. Those who need to stop using this medication should talk to their doctor about the safest way to slowly reduce its usage.

Can I stop 25 mg of Topamax cold turkey?

You should not stop taking any dosage of Topamax suddenly, since this can cause potentially serious effects, such as frequent or severe seizures. If you take Topamax for migraines, stopping suddenly could cause migraines to return with greater severity or frequency.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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