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Ethosuximide Pregnancy and Breastfeeding Warnings

Ethosuximide is also known as: Zarontin

Ethosuximide Pregnancy Warnings

Ethosuximide has not been formally assigned to a pregnancy category by the FDA. Ethosuximide has been assigned to pregnancy Risk Factor C by Briggs et al. Animal studies have not been reported. There are no controlled data in human pregnancy. An increased risk of congenital malformations have been associated with the use of anticonvulsants (including ethosuximide) in epileptic women during pregnancy. Abnormalities reported with ethosuximide use have included spontaneous hemorrhage in the neonate, patent ductus arteriosus, cleft lip and/or palate, mongoloid facies, short neck, altered palmar crease, an accessory nipple, and hydrocephalus. Anomalies associated with anticonvulsant use in pregnancy included neural tube defects, cleft lips, cleft palates, cardiac defects, and microcephaly. The manufacturer states that ethosuximide should only be administered during pregnancy when there are no alternatives and benefit outweighs risk.

To provide information regarding the effects of in utero exposure to ethosuximide, physicians are advised to recommend that pregnant patients taking ethosuximide enroll in the North American Antiepileptic Drug (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

See references

Ethosuximide Breastfeeding Warnings

Ethosuximide is excreted into human milk Concentrations found in breast milk are comparable to the maternal serum. The effects in the nursing infant are unknown. Ethosuximide is considered compatible with breast-feeding by the American Academy of Pediatrics.

See references

References for pregnancy information

  1. Nakane Y, Okuma T, Takahashi R, et al. "Multi-institutional study on the teratogenicity and fetal toxicity of antiepileptic drugs: a report of a collaborative study group in Japan." Epilepsia 21 (1980): 663-80
  2. "Product Information. Zarontin (ethosuximide)." Parke-Davis, Morris Plains, NJ.
  3. Fabro S, Brown NA "Teratogenic potential of anticonvulsants." N Engl J Med 300 (1979): 1280-1
  4. The National Institutes of Health. "Anticonvulsants found to have teratogenic potential." JAMA 245 (1981): 36
  5. Koup JR, Rose JQ, Cohen ME "Ethosuximide pharmacokinetics in a pregnant patient and her newborn." Epilepsia 19 (1978): 535-9
  6. Briggs GG, Freeman RK, Yaffe SJ.. "Drugs in Pregnancy and Lactation. 6th ed." Philadelphia, PA: Lippincott Williams & Wilkins (2002):

References for breastfeeding information

  1. Briggs GG, Freeman RK, Yaffe SJ.. "Drugs in Pregnancy and Lactation. 6th ed." Philadelphia, PA: Lippincott Williams & Wilkins (2002):

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