Drugs in lactation Source: LactMed

Methylnaltrexone and Breastfeeding

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 in milk and infant serum

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.

Source: Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, NCBI Bookshelf. Check LactMed for the most recent revision.

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