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

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

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

Use caution when driving, operating machinery, or performing other hazardous activities. Trimethadione may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

What is trimethadione?

Trimethadione is a seizure medication. The exact way that it works is unknown.

Trimethadione is used to control absence ("petit mal") seizures.

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

What should I discuss with my healthcare provider before taking trimethadione?

Before taking trimethadione, tell your doctor if you have

• liver disease;
• kidney disease;

• retinal or optic nerve (eye) disease;

• a disease of the blood or bone marrow; or

• acute intermittent porphyria.

You may not be able to take trimethadione, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

Trimethadione is in the FDA pregnancy category D. This means that it is known to be harmful to an unborn baby. Malformations of the face and head, heart, and nervous system have been reported. Do not take trimethadione without first talking to your doctor if you are pregnant or could become pregnant during treatment. It is not known whether trimethadione passes into breast milk and how it might affect a nursing infant. Do not use this medication without first talking to your doctor if you are breast-feeding a baby.

How should I take trimethadione?

Take trimethadione 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 trimethadione with a full glass of water.

Trimethadione can be taken on an empty stomach or with food to decrease stomach upset.

Chew the chewable tablets before swallowing them.

To ensure that you get a correct dose, measure the liquid form of trimethadione with a special dose-measuring spoon or cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

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 this medication even if you feel better. It is important to continue taking trimethadione to prevent the seizures from recurring. Store trimethadione at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the dose you missed and take only the 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 trimethadione overdose include dizziness, drowsiness, poor coordination, nausea, vomiting, and changes in vision.

What should I avoid while taking trimethadione?

Do not drink alcohol while taking this medication. Alcohol can cause deep sedation or sleepiness. It may also increase the risk of having seizures. Use caution when driving, operating machinery, or performing other hazardous activities. Trimethadione may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. Avoid prolonged exposure to sunlight. Trimethadione may increase the sensitivity of the skin to sunlight. Use a sunscreen and wear protective clothing when sun exposure is unavoidable.