The Basics
What is Ethosuximide?
Used to control absence seizures (petit mal).
Brand names for Ethosuximide
Zarontin
How Ethosuximide is classified
Anticonvulsants
Ethosuximide During Pregnancy
Ethosuximide pregnancy category
Category N/A
Note that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Ethosuximide while pregnant
To provide information regarding the effects of in utero exposure to Zarontin, physicians are advised to recommend that pregnant patients taking Zarontin enroll in the NAAED Pregnancy Registry. This can be done by calling the toll free number 1-888-233-2334, and must be done by patients themselves. Information on the registry can also be found at the website: http://www.aedpregnancvregistry.org/
Taking Ethosuximide While Breastfeeding
What are recommendations for lactation if you're taking Ethosuximide?
Average ethosuximide dosages of 50 to 60% of the maternal weight-adjusted dosage are excreted in human milk and infant plasma levels of 25 to 30% of maternal levels are common. Although no adverse effects attributable solely to ethosuximide in breastmilk have been reported, monitor the infant for drowsiness, adequate weight gain, and developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of anticonvulsants. Measurement of an infant serum level might help rule out toxicity if there is a concern.
Maternal / infant drug levels
Average ethosuximide dosages of 50 to 60% of the maternal weight-adjusted dosage are excreted in human milk and infant plasma levels of 25 to 30% of maternal levels are common. Although no adverse effects attributable solely to ethosuximide in breastmilk have been reported, monitor the infant for drowsiness, adequate weight gain, and developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of anticonvulsants. Measurement of an infant serum level might help rule out toxicity if there is a concern.
Possible effects of Ethosuximide on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Ethosuximide
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/
1. Koup JR, Rose JQ, Cohen ME. Ethosuximide pharmacokinetics in a pregnant patient and her newborn. Epilepsia. 1978;19:535-9. PMID: 104867
2. Kaneko S, Sato T, Suzuki K. The levels of anticonvulsants in breast milk. Br J Clin Pharmacol. 1979;7:624-7. Letter. PMID: 465285
3. Rane A, Tunell R. Ethosuximide in human milk and in plasma of a mother and her nursed infant. Br J Clin Pharmacol. 1981;12:855-8. PMID: 7340887
4. Kuhnz W, Koch S, Jacob S et al. Ethosuximide in epileptic women during pregnancy and lactation period. Placental transfer, serum concentration in nursed infants. Br J Clin Pharmacol. 1984;18:671-7. PMID: 6508976
5. Soderman P, Rane A. Ethosuximide and nursing. Acta Pharmacol Toxicol (Copenh). 1986;59 (Suppl 5 Pt 2): Abstract 513. PMID: 3766157
6. Meyer FP, Quednow B, Potrafki A, Walther H. [The perinatal pharmacokinetics of anticonvulsant drugs]. Zentralbl Gynakol. 1988;110:1195-205. PMID: 3239295
7. Tomson T, Villen T. Ethosuximide enantiomers in pregnancy and lactation. Ther Drug Monit. 1994;16:621-3. PMID: 7878705
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
