Ethionamide
Risk Factor: CM
Class: ANTI-INFECTIVES
/ Antituberculosis
Contents of this page:
Fetal Risk Summary
Breast Feeding Summary
References
Questions and Answers
Fetal Risk Summary
The oral anti-infective agent, ethionamide, is indicated for the treatment of tuberculosis when Mycobacterium tuberculosis is resistant to isoniazid or rifampin, or when the patient is intolerant to other drugs. Although it apparently has not been studied, the relatively low molecular weight (about 166) suggests that it is transferred to the fetus.
Ethionamide was teratogenic in rats and rabbits at doses higher than those used in humans (1). Nishimura and Tanimura (2), Shepard (3), and Schardein (4) have reviewed nine animal studies involving pregnant mice, rats, and rabbits. All of the studies, except one, showed various developmental anomalies.
Five human studies describing the outcome of pregnancies exposed to ethionamide have been briefly reviewed in three sources (2,3 and 4). Only one of the studies found an increased incidence of birth defects, reporting seven cases, two of which were Down's syndrome, from 23 exposed infants (2,3 and 4). The other reports found no association with congenital malformations (4).
Breast Feeding Summary
No reports describing the use of ethionamide in human lactation have been located. The relatively low molecular weight (about 166) suggests that ethionamide will be excreted into breast milk. The effects of this exposure on a nursing infant are unknown.
References
- Product information. Trecator. Wyeth-Ayerst Pharmaceuticals, 2001.
- Nishimura H, Tanimura T. Clinical Aspects of The Teratogenicity of Drugs. Amsterdam:Excerta Medica, 1976:13941.
- Shepard TH. Catalog of Teratogenic Agents. 9th ed. Baltimore, MD:The Johns Hopkins University Press, 1998:188.
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Schardein JL. Chemically Induced Birth Defects. 3rd ed. New York, NY:Marcel Dekker, 2000:3934.
