Topiramate is an antiepileptic medication that is also used to prevent migraines. The exact mechanism by which topiramate works to prevent migraines is not completely understood, but it is believed to work by affecting the activity of certain neurotransmitters in the brain, including GABA and glutamate. Topiramate appears to reduce the release of glutamate and enhance the activity of GABA, which can lead to a reduction in the frequency and severity of migraines. Additionally, topiramate may help prevent migraines by reducing the sensitivity of the nervous system to stimuli that can trigger migraines.