Drug reference

Ethosuximide

Antiepileptic · Anticonvulsant

AntiepilepticAnticonvulsant

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

3 major

SEVERE in our sources

PREGNANCY

Women of child-bearing potential should discuss with a

FDA category + note

Top interactions

BuprenorphineSevereDatabaseDDInter
DextropropoxypheneSevereDatabaseDDInter
Sodium OxybateSevereDatabaseDDInter

Mechanism

Ethosuximide exerts its antiepileptic effect by inhibiting T-type calcium channels, primarily in thalamic neurons. This action reduces the low-threshold calcium currents that are critical for the generation and propagation of the characteristic 3-Hz spike-and-wave discharges. By disrupting this abnormal neuronal activity in the thalamocortical circuitry, ethosuximide effectively suppresses absence seizures.

Indications

Absence seizuresAbsence syndromesabsence seizure

Dosing

Adult: Initially 500 mg daily in 2 divided doses, increased by 250 mg every 5-7 days. Usual: 1-1.5 g daily in 2 divided doses.
Pediatric: 6-17 years: initially 250 mg BD, increase by 250 mg every 5-7 days. Usual: 20 mg/kg daily.
Max dose: 2 g daily

Pharmacokinetics

Protein binding

not protein bound

Side effects

Common

gastro-intestinal intolerancetirednessmood changesagitationheadachedrowsinessinability to concentrate

Serious

rashes
DLE
blood dyscrasias (rare)
no liver or kidney damage

Pregnancy & lactation

Pregnancy

Women of child-bearing potential should discuss with a

Lactation

Readily transferred into breast-milk causing high infant serum-drug concentrations. Infants should be monitored for sedation, feeding difficulties, adequate weight gain, and developmental milestones. Serum-drug concentration monitoring should be undertaken if suspected adverse reactions develop. If toxicity develops, formula feeds or weaning may be necessary.