Kalamazoo Nerve Center, PLLC

Phenytoin (Dilantin®, Phenytek®)

Phenytoin (Dilantin, Phenytek)

Phenytoin (Dilantin®, Phenytek®) is an anti-epileptic medication (AED) used for the treatment of certain types of epilepsy. Phenytoin is one of the most widely prescribed medications for the management of seizures.

Phenytoin may reduce the number and severity of seizures experienced by someone with epilepsy, but it is not a cure for epilepsy.

What are the clinical uses of phenytoin?

When used properly, phenytoin may reduce the frequency and severity of tonic-clonic (grand mal) and complex partial (psychomotor, temporal lobe) seizures. Phenytoin is also used to prevent seizures from occurring during or following neurosurgery, and as a treatment for trigeminal neuralgia and certain cardiac arrhythmias.

Your doctor may prescribe phenytoin for other medical conditions.

How does phenytoin work?

Although the cause of epilepsy is unknown, some seizures are thought to occur because of excessive electrical activity in certain parts of the brain. Although the mechanism by which phenytoin prevents seizures is not fully understood, medical studies indicate that phenytoin works to suppress abnormal brain activity by stabilizing the inactive state of the parts of nerve cells called voltage-gated sodium channels. This reduces the electrical conductance among brain cells, allowing more normal electrical activity to propagate.

How is phenytoin taken?

Phenytoin is available as an extended-release capsule, a chewable tablet, and a liquid to take by mouth. The chewable tablet and liquid are usually taken two or three times a day. The extended-release capsules are usually taken one to four times a day.

Try to take phenytoin at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand.

Your doctor may start you on a low dose of phenytoin and gradually increase your dose.

It is important that you continue to take phenytoin even if you feel well. Do not stop taking phenytoin without talking to your doctor, even if you experience side effects such as unusual changes in behavior or mood. If you have a seizure disorder and you suddenly stop taking phenytoin, your seizures may become worse.

If you and your doctor choose to stop phenytoin, you may be instructed to decrease your dose gradually. Follow these instructions carefully.

Talk to your doctor about any preexisting medical conditions and any other medications, supplements, vitamins, and herbal products you are taking before using phenytoin. Once you begin using phenytoin, consult your doctor before taking any new medications, supplements, vitamins, or herbal products.

Take phyentoin exactly as directed by your doctor. Do not take more or less of it or take it more often than prescribed by your doctor.

What are the side effects of phenytoin?

Common side effects of phenytoin may include clumsiness, insomnia, motor twitching, nausea, rash, gum overgrowth, hairiness and thickening of features. People taking phenytoin should tell their doctor if any of these symptoms persist or cannot be tolerated.

Safety for use during pregnancy has not been established. Women who are taking this medication and who would like to become pregnant should discuss treatment options with their physicians before the pregnancy begins. If you become pregnant while taking phenytoin, talk to your doctor immediately. Phenytoin may cause other side effects that may be serious and indicate that your body is not tolerating the drug properly. If you experience a change in seizures, severe rash, or allergic reaction contact your doctor immediately as these may indicate potentially life-threatening problems.

Read the medication guide that you receive with the medication for a complete list of possible side effects. You may also learn more about phenytoin from the National Institutes of Health (NIH). Speak with your doctor if you are concerned about possible side effects you may be experiencing.

Reference: The National Library of Medicine