Drug Levels and Effects:

Summary of Use during Lactation:

Limited information indicates that lepirudin in doses up to 100 mg daily produce very low levels in milk. Because of its large molecular weight, it would not be expected to be absorbed from breastmilk by the infant. Lepirudin would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months.

Drug Levels:

Maternal Levels.

One mother who was 10 weeks postpartum received lepirudin 50 mg twice daily subcutaneously. Her breastmilk had undetectable (<0.1 mg/L) lepirudin levels3hours after a dose.

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

One infant was breastfed for3months during therapeutic lepirudin use beginning at 7 weeks of age. No bleeding events occurred.[1]

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.


1. Lindhoff-Last E, Willeke A, Thalhammer C et al. Hirudin treatment in a breastfeeding woman. Lancet. 2000;355:467-8. PMID:10841132

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Hirudin

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

    Disclaimer:Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.