ReadYourDNA

Ethosuximide (Zarontin)

Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.

About Ethosuximide

What it is

Ethosuximide is an anticonvulsant that blocks T-type calcium channels in the thalamus, which drive the brief lapses of awareness in absence seizures. It is a first-choice treatment for childhood absence epilepsy. It is sold as Zarontin, among other names.

How genes come into it

Ethosuximide is broken down mainly by CYP3A4. The gene studies on it, from a large trial in childhood absence epilepsy, looked at the T-type calcium channel genes CACNA1H and CACNA1I, which make its targets, and at SCN1A, for how well it controlled seizures. The findings come from a few studies, and there is no CPIC or DPWG guideline.

What research found

Every published finding on gene variants and Ethosuximide. Upload your DNA file to see which of these rows apply to you.

Rated evidence (1 rated variant)

PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.

SCN1A rs2298771: Level 4. Efficacy: Epilepsy. 4.

Response (3 findings)

Studies of how well it worked in people carrying a variant.

CACNA1H rs61734410: Allele T is associated with decreased clinical benefit to ethosuximide in children with Epilepsy as compared to allele C.

CACNA1I rs3747178: Allele T is associated with decreased clinical benefit to ethosuximide in children with Epilepsy as compared to allele C.

SCN1A rs2298771: Allele C is associated with increased response to carbamazepine, clobazam, ethosuximide, lamotrigine, levetiracetam, oxcarbazepine or valproic acid in children with Epilepsy as compared to allele T.

Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.

Related Drugs

More drugs from the same category

Antiepileptics (class) (Anticonvulsants)

Cerebyx (Anticonvulsants)

Depakote (Anticonvulsants)

Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.

Back to Medications

Content updated September 2026.

ReadYourDNA provides educational interpretation of DNA data you already have. It is not diagnostic, not a substitute for professional medical advice, diagnosis, or treatment, and is not intended to diagnose, treat, cure, or prevent any disease. Talk to a clinician before acting on any result.

Raw DNA Data Reports for 23andMe & AncestryDNA · About ReadYourDNA · FAQ · Methodology & Science · Pricing · Support and complaints · Legal & Contact · Health Traits · Pharmacogenomics · Carrier Status · Variant Explorer · The Human Karyotype · Privacy Policy · Terms of Service · Accessibility · Consumer Health Data Privacy · Your Privacy Choices · Editorial Standards · Your Data, Checkable · Sample Report · ReadYourDNA and Promethease compared · What is inside a 23andMe raw data file · What is inside an AncestryDNA raw data file · What a chatbot can and cannot do with your raw DNA file · Where a raw DNA file can still be uploaded in 2026

Written, maintained and operated by Martin Pechhacker, sole proprietor, Vienna, Austria. Trade register GISA 40064420. support@readyourdna.com