Celontin

(Methsuximide)

The active ingredient in Celontin is methsuximide.

Methsuximide belongs to the succinimide class of anticonvulsants, and its mechanism of action works by reducing abnormal electrical activity in the brain that can trigger absence seizures.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Celontin. However, the following is a synopsis of the general guidelines for the use of Celontin:

• Celontin capsules are taken by mouth, usually in divided doses as prescribed.
• Your healthcare provider will adjust the dose slowly until your seizures are well controlled.
• Take Celontin exactly as directed and at the same time each day.
• Do not change your dose or stop taking it without guidance, as seizures may worsen.
• If you miss a dose, take it when remembered unless it is close to the next dose. Do not double doses.
• Celontin is often taken along with other anticonvulsants such as phenobarbital or phenytoin when needed.

Some mild or common side effects of Celontin seen in clinical trials as compared to placebo include:

• Drowsiness or tiredness.
• Dizziness or unsteadiness.
• Nausea, vomiting, or stomach discomfort.
• Loss of appetite or weight loss.
• Constipation.
• Headache.
• Blurred vision.
• Sleep problems.

Some individuals may experience serious side effects while using Celontin. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Signs of allergic reaction, such as skin rash, hives, swelling, or trouble breathing.
• Unusual changes in mood or behavior, including suicidal thoughts.
• Severe drowsiness, confusion, or difficulty staying awake.
• Easy bruising, bleeding, sore throat, fever, or other signs of blood disorders.
• Dark urine, yellowing of the skin or eyes, or severe abdominal pain may indicate liver problems.
• Joint pain, rash, or symptoms suggesting systemic lupus erythematosus.
• Worsening seizures or new seizure types.

These are not all of the possible side effects of Celontin. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Celontin, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including:

• A history of depression, anxiety, suicidal thoughts, or mood disorders.
• Liver disease or abnormal liver test results.
• Blood disorders or a history of anemia.
• Systemic lupus erythematosus.
• Severe kidney problems.
• Any allergic reactions to succinimide anticonvulsants.
• A history of worsening seizures with other seizure medicines.

Celontin should not be used in individuals who have:

• A known hypersensitivity to methsuximide or other succinimides.
• A history of severe reactions to anticonvulsants in this class.

Some individuals may notice improvements in seizure control within several days, but full benefit may take several weeks as dosing is adjusted. Regular follow-up with your healthcare provider is important to confirm that the dose is effective and well-tolerated.

When Celontin is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• Phenobarbital may alter the effects of Celontin or increase sedation.
• Phenytoin may cause changes in blood levels when taken with Celontin.
• Other seizure medicines may need dosage adjustments to avoid toxicity or worsening seizures.
• Always speak with your healthcare provider before adding or stopping medications.

Celontin is available as oral capsules containing methsuximide. Strengths may vary by manufacturer. Your doctor will determine the dose based on age, response, and seizure control needs.

It should be stored at room temperature, away from the reach of children or pets.

Celontin is manufactured by Pfizer Inc.

Yes. Generic methsuximide capsules are available in some markets and may be prescribed as an alternative to the brand.

Do not stop taking Celontin abruptly. Sudden withdrawal may worsen seizures or trigger status epilepticus. Your healthcare provider will guide you through a gradual dose reduction if stopping is necessary.

Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you. Pregnant patients taking antiepileptic drugs may be eligible for enrollment in a pregnancy registry to monitor outcomes.

Talk to your doctor if you are already breastfeeding or if you have any plans to breastfeed. Small amounts of methsuximide may pass into breast milk, and your healthcare provider will decide whether Celontin is appropriate while nursing.