Celontin

Methsuximide comes as a capsule to take by mouth. It is usually taken one or more times a day. Take methsuximide at around the same time(s) 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 methsuximide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of methsuximide and gradually increase your dose, not more often than once a week.

Methsuximide may help control your condition but will not cure it. Continue to take methsuximide even if you feel well. Do not stop taking methsuximide without talking to your doctor, even if you experience side effects such as unusual changes in behavior or mood. If you suddenly stop taking methsuximide, your seizures may worsen. Your doctor will probably decrease your dose gradually.

Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Celontin is indicated for the control of absence (petit mal) seizures that are refractory to other drugs.

Blood Dyscrasias

Blood dyscrasias, including some with fatal outcome, have been reported to be associated with the use of succinimides; therefore, periodic blood counts should be performed. Should signs and/or symptoms of infection (eg, sore throat, fever) develop, blood counts should be considered at that point.

Effects On Liver

It has been reported that succinimides have produced morphological and functional changes in animal liver. For this reason, methsuximide should be administered with extreme caution to patients with known liver or renal disease. Periodic urinalysis and liver function studies are advised for all patients receiving the drug.

Systemic Lupus Erythematosus

Cases of systemic lupus erythematosus have been reported with the use of succinimides. The physician should be alert to this possibility.

Suicidal Behavior And Ideation

Antiepileptic drugs (AEDs), including Celontin, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior.

Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebotreated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide.

The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed.

The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication.

The risk did not vary substantially by age (5–100 years) in the clinical trials analyzed.

Table 1 shows absolute and relative risk by indication for all evaluated AEDs.

Table 1 : Risk by indication for antiepileptic drugs in the pooled analysis

The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications.

Anyone considering prescribing Celontin or any other AED must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.

Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm. Behaviors of concern should be reported immediately to healthcare providers.

Usage In Pregnancy

Reports suggest an association between the use of anticonvulsant drugs by women with epilepsy and an elevated incidence of birth defects in children born to these women. Data are more extensive with respect to phenytoin and phenobarbital, but these are also the most commonly prescribed anticonvulsants; less systematic or anecdotal reports suggest a possible similar association with the use of all known anticonvulsant drugs.

The reports suggesting an elevated incidence of birth defects in children of drug-treated epileptic women cannot be regarded as adequate to prove a definite cause and effect relationship. There are intrinsic methodologic problems in obtaining adequate data on drug teratogenicity in humans; the possibility also exists that other factors, eg, genetic factors or the epileptic condition itself, may be more important than drug therapy in leading to birth defects. The great majority of mothers on anticonvulsant medication deliver normal infants. It is important to note that anticonvulsant drugs should not be discontinued in patients in whom the drug is administered to prevent major seizures because of the strong possibility of precipitating status epilepticus with attendant hypoxia and threat to life. In individual cases where the severity and frequency of the seizure disorder are such that the removal of medication does not pose a serious threat to the patient, discontinuation of the drug may be considered prior to and during pregnancy, although it cannot be said with any confidence that even minor seizures do not pose some hazard to the developing embryo or fetus.

The prescribing physician will wish to weigh these considerations in treating or counseling epileptic women of childbearing potential.

Before you take Celontin, tell your healthcare provider if you:

• have or have had liver problems
• have or have had depression, mood problems or suicidal thoughts or behavior
• have any other medical conditions
• are pregnant or plan to become pregnant. It is not known if Celontin can harm your unborn baby. Tell your healthcare provider right away if you become pregnant while taking Celontin. You and your healthcare provider will decide if you should take Celontin while you are pregnant.
• are breastfeeding or plan to breastfeed. It is not known if Celontin can pass into breast milk. You and your healthcare provider should decide how you will feed your baby while you take Celontin.

Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. 

Tell your healthcare provider if you 

• are pregnant or plan to become pregnant. It is not known if Celontin can harm your unborn baby. Tell your healthcare provider right away if you become pregnant while taking Celontin. You and your healthcare provider will decide if you should take Celontin while you are pregnant.

  • If you become pregnant while taking Celontin, talk to your healthcare provider about registering with the North American Antiepileptic Drug (NAAED) Pregnancy Registry. The purpose of this registry is to collect information about the safety of antiepileptic drugs during pregnancy. You can enroll in this registry by calling 1-888-233-2334.

Take Celontin exactly as prescribed. Your healthcare provider will tell you how much Celontin to take.

• Your healthcare provider may change your dose. Do not change your dose of Celontin without talking to your healthcare provider.
• If you take too much Celontin, call your healthcare provider or your local Poison Control Center right away.

What you should avoid while taking Celontin:

• Do not drink alcohol or take other medicines that make you sleepy or dizzy while taking Celontin without first discussing this with your healthcare provider. Celontin taken with alcohol or medicines that cause sleepiness or dizziness may make your sleepiness or dizziness worse.
• Do not drive, operate heavy machinery, or do other dangerous activities until you know how Celontin affects you. Celontin can slow your thinking and motor skills.

• If you have an allergy to methsuximide or any other part of Celontin (methsuximide).
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

Use this medicine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take with or without food. Take with food if it causes an upset stomach.
• Do not take capsules that are not full or capsules where the contents have melted.
• To gain the most benefit, do not miss doses.
• Keep taking Celontin as you have been told by your doctor or other health care provider, even if you feel well.
• Take this medicine at the same time of day.
• Do not change the dose or stop Celontin. This could cause seizures. Talk with your doctor.

What do I do if I miss a dose?

• Take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

Gastrointestinal System: Gastrointestinal symptoms occur frequently and have included nausea or vomiting, anorexia, diarrhea, weight loss, epigastric and abdominal pain, and constipation.

Hemopoietic System: Hemopoietic complications associated with the administration of methsuximide have included eosinophilia, leukopenia, monocytosis, and pancytopenia with or without bone marrow suppression.

Nervous System: Neurologic and sensory reactions reported during therapy with methsuximide have included drowsiness, ataxia or dizziness, irritability and nervousness, headache, blurred vision, photophobia, hiccups, and insomnia. Drowsiness, ataxia, and dizziness have been the most frequent side effects noted. Psychologic abnormalities have included confusion, instability, mental slowness, depression, hypochondriacal behavior, and aggressiveness. There have been rare reports of psychosis, suicidal behavior, and auditory hallucinations.

Integumentary System: Dermatologic manifestations which have occurred with the administration of methsuximide have included urticaria, Stevens-Johnson syndrome, and pruritic erythematous rashes.

Cardiovascular: Hyperemia.

Genitourinary System: Proteinuria, microscopic hematuria.

Body as a Whole: Periorbital edema.

There are no data on the excretion of methsuximide into human milk.