Ethosuximide
Ethosuximide is an antiepileptic medication primarily used to treat absence seizures (petit mal seizures) in both children and adults. It is often considered a first-line treatment for childhood absence epilepsy and works by reducing seizure activity in the brain. Ethosuximide is typically prescribed when absence seizures occur without other types of seizures.
Ethosuximide is an antiepileptic drug used to control absence seizures.
Key facts at a glance
- ATC
- N03AD01
- RxNorm
- 4135
- Generic
- Ethosuximide
- Class
- atc-n03
- Brands
- Zarontin
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- solution, capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Ethosuximide is primarily indicated for the treatment of absence seizures (petit mal seizures) in patients with epilepsy. It is most commonly used in children ages 3-10 and is particularly effective for pure absence seizures without co-existing generalized tonic-clonic seizures. It may also be used in combination with other antiepileptic drugs when multiple seizure types are present.
Ethosuximide works by blocking T-type calcium channels in thalamic neurons, which play a key role in generating the abnormal electrical patterns characteristic of absence seizures. By suppressing these oscillations, the medication helps prevent the brief, sudden interruptions in consciousness that define absence seizures.
Common side effects may include drowsiness, dizziness, headache, and gastrointestinal upset. Rare but serious side effects can include blood disorders and systemic lupus erythematosus. Patients should have regular blood counts and liver function monitoring during treatment. Ethosuximide should not be stopped abruptly as this may increase seizure frequency. Effectiveness and tolerability vary between individuals, and dosing should be individualized under medical supervision.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy