What is Celontin: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Celontin overview

BRAND NAMES:

  • Celontin Kapseals

Generic Names:

  • Celontin

Uses:

  • Treats absence seizures (also called petit mal seizures) after other medicines have been tried, but are unable to control the seizures. This medicine is an anticonvulsant.

Therapeutic Classes:

  • Anticonvulsant

Forms:

  • Capsule

How it’s taken:

  • By mouth

What is Celontin used for?

Celontin is used to treat patients with absence seizures. Celontin works by controlling the abnormal electrical activity within the brain to prevent a seizure.

What form(s) does Celontin come in

  • Capsule

What are common Celontin doses?

  • Capsule 300MG

Common Celontin prescriptions

  • Celontin
    300mg capsule

How to take Celontin

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.

  • This medicine may be used with other seizure medicines. Keep using all of your seizure medicines unless your doctor tells you to stop.

  • 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.

  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.

  • 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.

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.

  • This medicine may be used with other seizure medicines. Keep using all of your seizure medicines unless your doctor tells you to stop.

  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.

What to do if you miss a dose of Celontin

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Oral routeAsk your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Celontin contraindications

  • You should not use this medicine if you have had an allergic reaction to methsuximide or similar medicines such as ethosuximide (Zarontin®).

Celontin warnings

  • Make sure your doctor knows if you are breastfeeding, or if you have kidney disease, liver disease, a blood or bone marrow disorder, or a history of depression.

  • It is important to tell your doctor if you become pregnant while using this medicine. Your doctor may want you to join a pregnancy registry for patients taking a seizure medicine.

  • 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.

  • For some children, teenagers, and young adults, this medicine 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 using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely.

  • This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.

  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments. Blood and urine tests may be needed to check for unwanted effects.

  • Swelling around the eyes.

  • Unusual behavior or thoughts of hurting yourself.

  • Unusual bleeding, bruising, or weakness.

  • Unusual depression, aggressiveness, confusion, irritability, or other changes in behavior.

Celontin interactions

  • Do not stop using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely.

  • For some children, teenagers, and young adults, this medicine 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.

  • 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.

  • 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).

  • Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.

  • Do not drink alcohol while you are using this medicine.

  • Make sure your doctor knows if you are also using other medicine for seizures (such as phenobarbital, phenytoin, Depakote®, Dilantin®, Keppra„¢, Luminal®, or Tegretol®).

  • This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.

  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments. Blood and urine tests may be needed to check for unwanted effects.

Celontin side effects

Serious Side Effects

  • Unusual bleeding, bruising, or weakness.

  • Sores or white patches in your mouth or throat.

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Blistering, peeling, or red skin rash.

  • Bloody or cloudy urine.

  • Fever, chills, cough, sore throat, and body aches.

  • Increase in number of seizures.

  • Problems with balance or walking.

  • Red, swollen, or painful joints.

  • Severe nausea, vomiting, or sleepiness.

  • Unusual behavior or thoughts of hurting yourself.

  • Unusual depression, aggressiveness, confusion, irritability, or other changes in behavior.

  • Swelling around the eyes.

Less Serious Side Effects

  • Hiccups.

  • Mild skin rash.

  • Headache.

  • Mild nausea, vomiting, diarrhea, constipation, or stomach pain.

  • Loss of appetite or weight loss.

  • Dizziness or drowsiness.

  • Blurred vision.

  • Trouble with sleeping.

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