Medically reviewed on June 7, 2018
Commonly used brand name(s)
In the U.S.
- Celontin Kapseals
Available Dosage Forms:
Therapeutic Class: Anticonvulsant
Chemical Class: Succinimide
Uses For methsuximide
Methsuximide is used to control absence (petit mal) seizures in the treatment of epilepsy. It is used after other medicines have been tried, but are unable to control the seizures. Methsuximide is an anticonvulsant that works in the brain tissue to stop seizures.
Methsuximide is available only with your doctor's prescription.
Before Using methsuximide
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For methsuximide, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to methsuximide or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of methsuximide in children.
No information is available on the relationship of age to the effects of methsuximide in geriatric patients. However, elderly patients are more likely to have age-related kidney or liver disease, which may require caution in patients receiving methsuximide.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with Medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking methsuximide, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using methsuximide with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using methsuximide with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with Food/Tobacco/Alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of methsuximide. Make sure you tell your doctor if you have any other medical problems, especially:
- Blood disorders or
- Bone marrow problems or
- Depression, history of or
- Grand mal or tonic-clonic seizures or
- Kidney disease or
- Liver disease or
- Systemic lupus erythematosus (immune system disease)—Use with caution. May make these conditions worse.
- Infection—May reduce your body’s ability to fight an infection.
Proper Use of methsuximide
Take methsuximide only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
If you notice that your capsules are not full or the contents have melted, call your pharmacist right away. The medicine may not work properly and should not be used.
Methsuximide may be used with other seizure medicines. Keep using all of your seizure medicines unless your doctor tells you to stop.
Methsuximide comes with a Medication Guide. It is very important that you read and understand this information. Be sure to ask your doctor about anything you do not understand.
The dose of methsuximide will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of methsuximide. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (capsules):
- For seizures:
- Adults, teenagers, and children—At first, 300 milligrams (mg) once a day. Your doctor may increase your dose if needed.
- For seizures:
If you miss a dose of methsuximide, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Methsuximide melts easily, so do not store it in a place that is very hot (e.g., closed cars, delivery vans, or near steam pipes).
Precautions While Using methsuximide
It is very important that your doctor check your progress at regular visits while you are using methsuximide to see if it is working properly and to allow for a change in the dose. Blood and urine tests may be needed to check for any unwanted effects.
It is important to tell your doctor if you become pregnant while using methsuximide. Your doctor may want you to join a pregnancy registry for patients taking a seizure medicine.
For some children, teenagers, and young adults, methsuximide can increase thoughts of suicide. Tell your doctor or your child's doctor right away if you or your child start to feel more depressed or have thoughts about hurting yourself. Report any unusual thoughts or behaviors that trouble you or your child, especially if they are new or get worse quickly. Make sure the doctor knows if you or your child have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell the doctor if you or your child have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. Let the doctor know if you, your child, or anyone in your family has bipolar disorder (manic-depressive) or has tried to commit suicide.
Do not stop taking methsuximide without first checking with your doctor. Your doctor may want you or your child to gradually reduce the amount you are using before stopping completely.
Tell your doctor right away if you or your child feels unusually weak, starts bruising easily, has bleeding gums or nosebleeds, seems to be sick more often, has a fever, swollen glands, or a sore throat that will not go away. These could be a signs of a serious problem with the number of blood cells in your body.
Tell your doctor right away if you or your child has a skin rash, muscle or joint pain, feels unusually tired, has a low-grade fever, or pain the chest that gets worse with breathing. These could be signs of a serious condition called systematic lupus erythematosus (SLE).
Call your doctor right away if you or your child start to have a persistent cough, weight loss, night sweats, fever, chills, or flu-like symptoms such as a runny or stuffy nose, headache, blurred vision, or feeling generally ill. These may be signs that you have an infection.
Methsuximide may cause some people to become dizzy, drowsy, or less alert than they are normally. Make sure you know how you react to methsuximide before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.
Methsuximide Side Effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Attempts at killing oneself
- feeling that others are watching you or controlling your behavior
- feeling that others can hear your thoughts
- feeling, seeing, or hearing things that are not there
- severe mood or mental changes
- unusual behavior
Incidence not known
- Attack, assault, or force
- blistering, peeling, or loosening of the skin
- blood in the urine
- bloody, black, or tarry stools
- chest pain
- cloudy urine
- cough or hoarseness
- feeling sad or empty
- high fever
- joint or muscle pain
- lack of appetite
- loss of interest or pleasure
- lower back or side pain
- mood or mental changes
- painful or difficult urination
- pale skin
- red skin lesions, often with a purple center
- red, irritated eyes
- shakiness and unsteady walk
- shortness of breath
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- swelling around the eyes
- swollen glands
- trouble with concentrating
- trouble with sleeping
- unexplained bleeding or bruising
- unsteadiness, trembling, or other problems with muscle control or coordination
- unusual bleeding or bruising
- unusual tiredness or weakness
- vision changes
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Change in consciousness
- difficult or troubled breathing
- irregular, fast or slow, or shallow breathing
- loss of consciousness
- pale or blue lips, fingernails, or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Incidence not known
- Blurred vision
- change in color vision
- difficulty having a bowel movement (stool)
- difficulty seeing at night
- hives or welts
- increased sensitivity of the eyes to sunlight
- loss of appetite
- nausea or vomiting
- pain or discomfort in the chest, upper stomach, or throat
- redness of the skin
- skin rash
- unable to sleep
- weight loss
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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More about methsuximide
- Methsuximide Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- En Español
- 0 Reviews
- Drug class: succinimide anticonvulsants
Other brands: Celontin