Risk Factor: C
Class: Gastrointestinal agents/ Laxatives/purgatives
Fetal Risk Summary
Senna, a naturally occurring laxative, contains the stereoisomeric glucosides sennosides A and B. These anthraquinone glucosides are prodrugs that are converted by bacterial enzymes in the colon to rhein-9-anthrone that is oxidized to rhein, the active cathartic agent of senna (1). Senna is not teratogenic in animals (2). No reports of human teratogenicity or other fetal toxicity have been located.
Breast Feeding Summary
Sennosides A and B are not excreted into human breast milk. A 1973 study using colorimetric analysis (sensitivity limit 0.34 g/mL) failed to detect the natural agents (3). The active metabolite, rhein, however, is excreted into milk in very small amounts (1). Lactating women administered 5 g of senna daily for 3 days excreted a mean 0.007% of the dose in their milk and no adverse effects were observed in the nursing infants. This is compatible with the fact that the anthraquinone laxatives are absorbed only slightly after oral administration (4). In addition to the study above (1), use of the laxative during lactation has been reported in three other studies (3,5,6). Although diarrhea occurred in some of the infants, this was probably related to other causes, not to senna. In one study, mothers who ingested a single 100-mg dose of senna (containing 8.6 mg of sennosides A and B) and whose infants developed diarrhea were later given a double dose of the laxative (3). No diarrhea was observed in the infants after the higher dose. The American Academy of Pediatrics considers senna to be compatible with breast feeding (7).
- Faber P, Strenge-Hesse A. Relevance of rhein excretion into breast milk. Pharmacology 1988;36 (Suppl 1):21220.
- Shepard TH. Catalog of Teratogenic Agents. 6th ed. Baltimore, MD: Johns Hopkins University Press, 1989:5745.
- Werthmann MW Jr, Krees SV. Quantitative excretion of Senokot in human breast milk. Med Ann Dist Col 1973;42:45.
- American Hospital Formulary Service. Drug Information 1997. Bethesda, MD: American Society of Health-System Pharmacists, 1997:22368.
- Baldwin WF. Clinical study of senna administration to nursing mothers: assessment of effects on infant bowel habits. Can Med Assoc J 1963;89:5668.
- Greenhalf JO, Leonard HSD. Laxatives in the treatment of constipation in pregnant and breast-feeding mothers. Practitioner 1973;210:25963.
- Committee on Drugs, American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 1994;93:13750.