Topamax (topiramate) is an oral medication used primarily to treat epilepsy in children and adults, and Lennox-Gastaut syndrome (a disorder that causes seizures and developmental delays) in children. It is also used for preventive treatment of migraine headaches (but not to stop them after they have started). It is part of a a class of medications called anticonvulsants. It works by affecting the receptors in the brain that control electrical activity.

Topamax has been used to treat bipolar disorder, however there has been research that showed there is no evidence that it works. Other research has shown that Topamax may be effective for the treatment of borderline personality disorder. Investigations are ongoing to see if it is effective for the treatment of alcoholism, obesity, post traumatic stress disorder, and binge eating disorder.

The exact way that Topamax works on the brain is still unknown, but it is believed that the drug works on sodium channels in the brain, GABA receptors, glutamate receptors, and other enzymes.