Trimethadione is used to control absence seizures (petit mal; a type of seizure in which there is a very short loss of awareness during which the person may stare straight ahead or blink his eyes and does not respond to others) when other medications will not work. Trimethadione is in a class of medications called anticonvulsants. It works by reducing abnormal electrical activity in the brain.
Trimethadione comes as a chewable tablet to take by mouth. It is usually taken three or four times a day. Take trimethadione at around the same times every 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.
The chewable tablets may be chewed or swallowed whole.
Trimethadione may help to control your condition but will not cure it. Continue to take trimethadione even if you feel well. Do not stop taking trimethadione without talking to your doctor. Your doctor probably will decrease your dose gradually. If you suddenly stop taking trimethadione, your seizures may become worse.
Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with trimethadione and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) to obtain the Medication Guide.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Unless your doctor tells you otherwise, continue your normal diet.
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.
changes in weight
numbness, burning, or tingling in the hands, arms, feet, or legs
difficulty falling asleep or staying asleep
difficulty coordinating movements
sensitivity to the sun
joint or muscle pain
chest pain or shortness of breath
swelling of your feet, ankles, or legs
weakness of your arms or legs
rash on the cheeks or other parts of the body
sores in the mouth
red- or purple-colored skin spots
extreme weakness or tiredness
yellowing of the skin or eyes
nausea or vomiting
loss of appetite
pain in the upper right part of the stomach
problems seeing in bright light
Trimethadione may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store trimethadione 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 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.
difficulty coordinating movements
changes in vision
coma (loss of consciousness for a period of time)
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to trimethadione.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Last Revised - 12/15/2012
AHFS® Consumer Medication Information. © Copyright, 2015. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.