Trimethadione (patient information)

# IMPORTANT WARNING:
Trimethadione is no longer available in the U.S. If you are currently taking trimethadione, you should call your doctor to discuss switching to another treatment.
Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking trimethadione, call your doctor immediately. Talk to your doctor about the risks of using this drug during pregnancy.

# Why is this medication prescribed
Trimethadione is used to treat a type of seizure called absence (petit mal) when other medications will not work. Trimethadione acts on the brain and nervous system in the treatment of epilepsy.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

# How should this medicine be used
Trimethadione comes as a capsule, chewable tablet, and liquid to take by mouth. It is taken three or four times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take trimethadione exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Continue to take trimethadione even if you feel well. Do not stop taking trimethadione without talking to your doctor, especially if you have taken large doses for a long time. Your doctor probably will decrease your dose gradually. Abruptly stopping the drug can cause seizures. It must be taken regularly to be effective.

# What special precautions should I follow
Before taking trimethadione
- tell your doctor and pharmacist if you are allergic to trimethadione or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially other seizure medications, doxycycline (Vibramycin), isoniazid (INH), medications for colds or allergies such as chlorpheniramine (Chlor-Trimeton), medications for depression such as amitriptyline (Elavil), oral contraceptives, and vitamins. Trimethadione affects the action of other medications, and many medications can affect the action of trimethadione. Tell your doctor and pharmacist everything you are taking.
- tell your doctor if you have or have ever had eye, kidney, or liver disease or a blood disorder.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking trimethadione.
- you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
- remember that alcohol can add to the drowsiness caused by this drug.
- plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. *Trimethadione may make your skin sensitive to sunlight.

# What special dietary instructions should I follow
Trimethadione may cause an upset stomach. Take trimethadione with food. Drink plenty of water.

# What should I do if I forget a dose
Take the missed dose as soon as you remember it. However, if you remember a missed dose at the time you are scheduled to take the next dose, skip the missed dose completely. Do not take a double dose to make up for a missed one.

# Side Effects

## Minor Side Effects
Trimethadione may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- drowsiness
- upset stomach
- vomiting
- constipation
- diarrhea
- difficulty swallowing
- loss of taste and appetite
- irritability
- headache
- speech problems
- tingling, burning, tight or pulling feeling

## Severe Side Effects
If you experience any of the following symptoms, call your doctor immediately:
- difficulty coordinating movements
- joint pain
- skin rash
- easy bruising
- tiny purple-colored skin spots
- bloody nose
- unusual bleeding
- yellowing of the skin or eyes
- dark urine
- fever
- sore throat
- burning when urinating
- frequent urination

# What storage conditions are needed for this medicine
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature, away from light, excess heat, and moisture (not in the bathroom). Store chewable tablets in the refrigerator. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

# In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

# What other information should I know
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to trimethadione.
Call your doctor if you continue to have seizures or convulsions while taking this medication.
If you give this drug to a child, observe and keep a record of the child's moods, behavior, attention span, hand-eye coordination, and ability to solve problems and perform tasks requiring thought. Ask the child's teacher to keep a similar record. This information can help the child's doctor determine whether to continue the drug or to change the dose or drug.
Wear identification (Medic Alert) indicating medication use and epilepsy.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

# Brand names
Tridione