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 ( Web Site) to obtain the Medication Guide.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Before taking trimethadione,
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.
Trimethadione may cause side effects. Tell your doctor if any of these symptoms or those listed in the SPECIAL PRECAUTIONS section are severe or do not go away:
Some side effects can be serious. If you experience any of these symptoms , call your doctor immediately:
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 ( Web Site ) 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.
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( Web Site) for more information if you do not have access to a take-back program.
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. Web Site
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at Web Site. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
Symptoms of overdose may include:
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.
AHFS® Consumer Medication Information. © Copyright, 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.
Selected Revisions: June 15, 2018.