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Bookshelf ID: NBK564288PMID: 33226751
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Drugs and Lactation Database (LactMed®) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006-.
CASRN: 83387-25-1
Drug Levels and Effects
Summary of Use during Lactation
No information is available on the use of methylnaltrexone during breastfeeding. The manufacturer recommends avoiding breastfeeding in mothers taking methylnaltrexone. Based on pharmacokinetic data, the oral absorption of methylnaltrexone appears to be very low. Observe breastfed infants who have been exposed to opioids during pregnancy or postpartum for signs of opioid withdrawal, especially diarrhea.
Drug Levels
Based on the serum AUC values of oral and subcutaneous methylnaltrexone in the product labeling, it appears that methylnaltrexone has an oral bioavailability of <5%.
Maternal Levels. Relevant published information was not found as of the revision date.
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.
Substance Identification
Substance Name
Methylnaltrexone
CAS Registry Number
83387-25-1
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.
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