Phenytoin is a medication that calms overactive nerves in your body. It helps treat symptoms of epilepsy by preventing and regulating seizures. It can also prevent seizures after brain surgery.

Phenytoin is used to prevent and control seizures (also called an anticonvulsant or antiepileptic drug). It works by reducing the spread of seizure activity in the brain.

Phenytoin is highly effective for seizures and is one of the most commonly used seizure medicines in North America. It is best used for partial-onset seizures, which begin in one area of the brain.

Phenytoin works by stabilizing certain brain activity, which helps to prevent seizures from occurring, as well as reducing the symptoms of mania, such as impulsivity and agitation.