Dosing and uses of Celontin (methsuximide)
Adult dosage forms and strengths
capsule
- 150mg
- 300mg
Absence Seizures
300 mg PO qDay
Increase by 300 mg/week to no more than 1.2 g/day in divided doses
May take with food or milk
Monitor: CBC
Pediatric dosage forms and strengths
capsule
- 150mg
- 300mg
Absence Seizures
<12 years: Not established
>12 years
- 300 mg PO qDay
- Increase by 300 mg/week to no more than 1.2 g/day in divided doses
- May take with food or milk
- Monitor: CBC
Geriatric dosage forms and strengths
Absence seizures
300 mg PO qDay
Increase by 300 mg/week to no more than 1.2 g/day in divided doses
May take with food or milk
Monitor: CBC
Celontin (methsuximide) adverse (side) effects
Frequency not defined
Common
- Ataxia, dizziness, somnolence
- Erythema
- Abdominal pain, constipation, diarrhea, epigastric pain, loss of appetite, nausea, vomiting, weight loss
- Hematuria, proteinuria
Serious
- Auditory hallucinations (rare), psychotic disorder (rare), suicidal behavior (rare)
- Stevens-Johnson syndrome
- Disorder of hematopoietic structure, leukopenia, monocytosis, pancytopenia
- Systemic lupus erythematosus
Warnings
Contraindications
Hypersensitivity
Cautions
Do not discontinue rapidly
Succinimides have been associated with blood dyscrasias
Pregnancy and lactation
Pregnancy category: C
Lactation: avoid during breastfeeding
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Celontin (methsuximide)
Mechanism of action
Succinimide; depresses motor cortex, increases convulsive stimuli threshold in CNs
Pharmacokinetics
Half-Life: 3 hr
Time: 1-3 hr
Concentration: 3-7 mcg/mL (dose-dependent)
Therapeutic plasma concentration: 10-40 mcg/mL
Metabolism: Liver
Excretion: Urine
