Primary Use: Treatment of tonic-clonic (grand mal) seizures and complex partial (psychomotor or temporal lobe) seizures in epilepsy. It is also used to prevent seizures during or after brain surgery and can be used as a second-line treatment for trigeminal neuralgia (facial nerve pain).
Mechanism of Action: Phenytoin works by blocking voltage-dependent sodium channels in neurons. This action inhibits the rapid, repetitive firing of nerve cells that causes seizure activity, thus preventing the spread of a seizure from its starting point.
Administration: The tablets (including chewable and extended-release capsules) are taken orally, usually at the same time each day. The dose is highly individualized, and regular blood tests are necessary to ensure levels stay within the therapeutic range of 10 to 20 mcg/mL, as the effective dose is close to the toxic dose.
