Lactation and Contamination of Breast Milk with Xenobiotics

Evan Begg, Sharon Gardiner, Carl Kirkpatrick

Research output: Chapter in Book/Report/Conference proceedingChapter (Book)Researchpeer-review

1 Citation (Scopus)


The health, economic, and sociologic benefits of breastfeeding are substantial. As a result, women are encouraged to exclusively breastfeed their infants until they are around six months of age. However, the transfer of drugs and other xenobiotics to the infant via breast milk is a frequent cause of concern. Many women requiring drug therapy interrupt or stop breastfeeding, or fail to take the prescribed treatment regimen. All drugs, with the exception of very large molecules such as insulin, transfer into milk and may potentially pose risk. However, the extent of transfer varies widely between drugs, usually in accordance with the principles of passive diffusion of unionized and unbound drug. Risk to the suckling infant is best assessed via consideration of the likely 'dose' of drug that will be ingested via milk, the infant's clearance, the plasma concentration that results from these, and the possible pharmacological effects. It is usually possible to select a drug that is safe and effective for the mother while posing minimal risk to her infant. Maternal drug therapy should rarely be a reason to avoid or interrupt breastfeeding. However, in rare instances such as during maternal chemotherapy, breastfeeding is best avoided.

Original languageEnglish
Title of host publicationReproductive and Endocrine Toxicology
EditorsCharlene A McQueen
Place of PublicationUnited States
Number of pages11
ISBN (Print)9780080468686
Publication statusPublished - 12 Aug 2010
Externally publishedYes

Publication series

NameComprehensive Toxicology


  • Breastfeeding
  • Drug milk level
  • Human milk
  • Lactation

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