Methsuximide Dosage

Medically reviewed by Drugs.com. Last updated on Jul 22, 2025.

Usual Adult Dose for Seizures

Initial dose: 300 mg orally once a day for the first week

• If needed, increase the daily dosage in increments of 300 mg/day at weekly intervals

Maximum dose: 1200 mg/day

Comments:

• The above dosing is suggested, however, because therapeutic effect and tolerance may vary among patients, therapy must be individualized according to the response of each patient.
• The optimal dose is the amount of drug which is barely sufficient to control seizures so that side effects may be kept to a minimum.

Use: For the control of absence (petit mal) seizures that are refractory to other drugs.

Usual Pediatric Dose for Seizures

Children:
Initial dose: 10 to 15 mg/kg/day orally in 3 to 4 divided doses

• May increase at weekly intervals

Maximum dose: 30 mg/kg/day

Comments:

• The above dosing is suggested, however, because therapeutic effect and tolerance may vary among patients, therapy must be individualized according to the response of each patient.
• The optimal dose is the amount of drug which is barely sufficient to control seizures so that side effects may be kept to a minimum.

Use: For the control of absence (petit mal) seizures that are refractory to other drugs.

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Precautions

CONTRAINDICATIONS:
Hypersensitivity to succinimides

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• Take orally

Storage requirements:

• Protect from light and moisture; protect from excessive heat (104F [40C])

General:

• Using this drug as monotherapy in patients with mixed type of epilepsy may increase the frequency of grand mal seizures in some patients.
• Abrupt withdrawal may precipitate seizures; as with other antiepileptic drugs, dose increases, and decreases should proceed slowly.

Monitoring:

• Blood counts, periodically, and if signs and/or symptoms of infection develop
• Urinalysis periodically
• Liver function tests periodically
• Monitor for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior
• Monitor for rash

Patient advice:

• Read the US FDA-approved patient labeling (Medication Guide).
• Patients should understand the importance of strictly adhering to their dosing regimen.
• Patients should be appropriately counseled regarding the performance of potentially hazardous tasks.
• Patients should be instructed to contact their healthcare provider promptly if they develop a rash or signs and symptoms of an infection.
• Patients and/or caregivers should monitor for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior; behaviors of concern should be reported promptly.
• Women of childbearing potential should speak with their physician if they are or intend to become pregnant or are breastfeeding.

See also:

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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