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What is the most important information I should know about mephenytoin?

Mephenytoin is not commercially available in the United States.

Do not stop taking your medication even if you feel better. It is important to continue taking mephenytoin to prevent your seizures from recurring.

Do not change the brand, generic formulation, or dosage of this medication without first talking to your doctor.

Carry or wear a medical identification tag to let others know that you are taking this medicine in the case of an emergency.

What is mephenytoin?

Mephenytoin is a drug used to control seizures. It works by slowing down impulses in the brain that cause seizures.

Mephenytoin is usually reserved for seizure conditions that have not responded to other less toxic antiseizure medicines.

Mephenytoin is not commercially available in the United States.

Mephenytoin may also be used for purposes other than those listed in this medication guide.

Who should not take mephenytoin?

Before taking this medication, tell your doctor if you have kidney or liver disease. You may not be able to take mephenytoin, or you may require a lower dose or special monitoring during treatment.

Mephenytoin may increase blood sugar. If you are a diabetic and are taking mephenytoin, watch for changes in your blood sugar levels that may be caused by this medication.

Mephenytoin is in the FDA pregnancy category C. This means that it is not known whether mephenytoin will harm an unborn baby. Do not take mephenytoin without first talking to your doctor if you are pregnant. Mephenytoin passes into breast milk and may affect a nursing infant. Do not take mephenytoin without first talking to your doctor if you are breast-feeding a baby.

How should I take mephenytoin?

Take mephenytoin exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose of mephenytoin with a full glass of water. Take mephenytoin with food to lessen stomach upset

Do not change the brand name, generic formulation, or dosage of mephenytoin that you are taking without first talking to your doctor.

Carry or wear a medical identification tag to let others know that you are taking this medicine in the case of an emergency.

Do not stop taking your medication even if you feel better. It is important to continue taking mephenytoin to prevent your seizures from recurring.

Do not take any tablet that is discolored.

Store this medication at room temperature away from light and moisture.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the dose you missed and take only your next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical treatment.

Symptoms of a mephenytoin overdose include back-and-forth eye movements, slurred speech, stumbling or staggering walk, imbalance, drowsiness, unconsciousness, nausea, vomiting, tremor, low blood pressure, and slow breathing.

What should I avoid while taking mephenytoin?

Do not drink alcohol while taking this medication. Alcohol can cause deep sedation or sleepiness. It may also increase your risk of having seizures. Use caution when driving, operating machinery, or performing other hazardous activities. Mephenytoin may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.