NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-.

Cover of Drugs and Lactation Database (LactMed)

Drugs and Lactation Database (LactMed) [Internet].

Show details

Letrozole

Last Revision: June 21, 2021.

CASRN: 112809-51-5

image 135028595 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

No information is available on the use of letrozole during breastfeeding. The manufacturer recommends that breastfeeding be discontinued during letrozole therapy and for 3 weeks after the last dose.

Drug Levels

Maternal Levels. An abstract reported that a relative infant dose of 10.2% was found in nursing mother(s) taking letrozole, who provided 8 milk samples over 24 hours, but other details were not supplied.[1]

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

Effects in Breastfed Infants

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

Effects on Lactation and Breastmilk

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

References

1.
Monfort A, Jutras M, Martin B, et al. New data on the transfer of untested medication into breast milk. Birth Defects Res. 2021;113:831. Abstract.

Substance Identification

Substance Name

Letrozole

CAS Registry Number

112809-51-5

Drug Class

Breast Feeding

Lactation

Antineoplastic Agents

Aromatase Inhibitors

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.

Views

Related information

Similar articles in PubMed

  • Review Carmustine[Drugs and Lactation Database (...]
    Review Carmustine
    . Drugs and Lactation Database (LactMed). 2006
  • Review Exemestane[Drugs and Lactation Database (...]
    Review Exemestane
    . Drugs and Lactation Database (LactMed). 2006
  • Review Deferiprone[Drugs and Lactation Database (...]
    Review Deferiprone
    . Drugs and Lactation Database (LactMed). 2006
  • Review Dexrazoxane[Drugs and Lactation Database (...]
    Review Dexrazoxane
    . Drugs and Lactation Database (LactMed). 2006
  • Review Dactinomycin[Drugs and Lactation Database (...]
    Review Dactinomycin
    . Drugs and Lactation Database (LactMed). 2006
See reviews...See all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...