EBM Consult

Are breastfed infants with an active viral infection at an increased risk for developing Reye's syndrome if the mother is taking aspirin or salicylates?

Summary:

  • In the female that is nursing or breastfeeding, the NRSF and the World Health Organization (WHO) Working Group on Human Lactation considers aspirin intake by nursing mothers to be unsafe, due to the ability of the baby to receive about 4-8% of the mother's dose and that continuous exposure of small doses can cause a buildup of aspirin in the body of the infant.
  • The American Academy of Pediatrics Committee on Drugs (AAP) list aspirin and 5-aminosalicylic acid as, "drugs that have been associated with significant effects on some nursing infants and should be given to nursing mothers with caution".
  • Aspirin is known to have a lactation risk category of L3, which is designated as "moderately safe".
  • Due to the severity of Reye's syndrome, the presence of aspirin in the breast milk, and the availability of other analgesic options besides aspirin, it would be prudent to avoid the use of all aspirin or aspirin derivatives while breastfeeding an infant who is also experiencing a viral infection.

Editor-in-Chief: Anthony J. Busti, MD, PharmD, FNLA, FAHA

Last Reviewed: February 2018

Explanation

  • The National Reye's Syndrome Foundation (NRSF), the U.S. Surgeon General, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention recommend that aspirin and/or aspirin containing products not be given to anyone under the age of 19 years during a fever-causing illness.(1-3)  If a female is nursing or breastfeeding a child, the NRSF and the World Health Organization (WHO) Working Group on Human Lactation considers aspirin intake by nursing mothers to be unsafe.(1,4)  They base their recommendations on the fact that a nursing baby can receive about 4-8% of the mother's dose and that continuous exposure of small doses can cause of a buildup of aspirin in the body of the infant.(1,4,5)

    Other professional groups, such as the American Academy of Pediatrics Committee on Drugs (AAP) list aspirin and 5-aminosalicylic acid as, "drugs that have been associated with significant effects on some nursing infants and should be given to nursing mothers with caution".(6)  This recommendation is based on the 5-ASA causing diarrhea and aspirin being reported to cause metabolic acidosis.Other referenced texts also indicate that aspirin should not be used by a mother whose nursing infant has an active viral illness due to a small chance that the child may develop Reye's syndrome.(7)  While there is conflicting data as to the amount of aspirin exposure to a nursing infant with individual patient cases, one study evaluating 8 nursing women who took 1 gram of aspirin found the average salicylate milk concentrations to be 2.4 mg/mL at 3 hours and the average salicyluric acid milk concentrations to be 10.2 mg/L at 9 hours.(8-10)  The authors suggested these levels translated into a relative infant dose of 9.4% of the maternal dose.10  Due to the available data, aspirin was given a lactation risk category of L3, which is designated as "moderately safe".(7)

    The characteristics of a medication that facilitate its ability to enter into the breast milk include:

    • Ability to attain high plasma concentrations in the breastfeeding mother
    • Having a low molecular weight defined as being approximately less than 500
    • Having a low degree of protein binding
    • Ability to pass into the brain easily or have a higher degree of lipophilicity.(7)  

    Aspirin is known to meet a couple of these characteristics that are likely contributing to some of its presence in breast milk with its molecular weight being 179 g/mol and being highly lipid soluble.(11)  The relative infant dose will not only factor in these characteristics but will also be influenced by the dose the mother ingested, timing of the administration in relation to breastfeeding, and the frequency of administration while nursing. 

    Despite the above recommendations from regulatory agencies, professional organizations and other reference resources, we are unaware of any documented cases of Reye's syndrome in a nursing infant receiving breast milk from a mother who also took aspirin.  Regardless, due to the severity of Reye's syndrome, the presence of aspirin in the breast milk, and the availability of other analgesic options besides aspirin, it would be prudent to avoid the use of all aspirin or aspirin derivatives while breastfeeding an infant who is also experiencing a viral infection.

Related Content

References

    1. National Reye's Syndrome Foundation.  What is Reye's Syndrome.   
    2. Centers for Disease Control and Prevention.  Surgeon General's Advisory on the Use of Salicylates and Reye Syndrome.  
    3. Food and Drug Administration.  Get set for the winter illness season.   
    4. National Toxicology Program. Department of Health and Human Services, National Institutes of Health.  Aspirin.   
    5. Findlay JW, DeAngelis RL, Kearney MF et al.  Analgesic drugs in breast milk and plasma.  Clin Pharmacol Ther 1981;29:625-33.  
    6. American Academy of Pediatrics Committee on Drugs.  Transfer of drugs and other chemicals into human milk.  Pediatrics  2001;108:776-89.  
    7. Hale TW.  Medications and Mother's Milk. 13th ed.  Hale Publishing.  Amarillo, Texas. 2008.
    8. Erickson SH, Oppenheim GL.  Aspirin in breast milk.  J Fam Pract  1979;8:189-90.  
    9. Bailey DN, Weibert RT, Naylor AJ et al.  A study of salicylate and caffeine excretion in the breast milk of two nursing mothers.  J Anal Toxicol  1982;6:64-8.  
    10. Putter J, Satravaha P, Stockhausen H.  Quantitative analysis of the main metabolites of acetylsalicylic acid. Comparative analysis in the blood and milk of lactating women.  Z Geburtshilfe Perinatol  1974;178:135-8.  
    11. PubChem Compound.  Aspirin - compound summary (CID 450661).  

Keywords

  • ASA, Aspirin, Breastfeeding, Reyes syndrome, Salicylates, Viral Illness