Lactation Safety Information

Moderate amount of published evidence shows low amounts of ritonavir in breast milk resulting in variable infant serum levels, ranging from undetectable to low. No adverse effects reported in breastfed infants to date.
No published evidence relating to use of nirmatrelvir in breastfeeding, but it is likely to pass into breast milk.
Paxlovid is administered as a short course, and nirmatrelvir and ritonavir both have a short half-life, so risk of accumulation in the infant is low.
The manufacturer’s advise that breastfeeding is not recommended during treatment with Paxlovid and for 7 days after the last dose. This is to ensure any infant exposure via breast milk is completely avoided.
As a precaution monitor infant for poor feeding, adequate weight gain, vomiting, diarrhoea, poor sleeping, and signs of jaundice.
Breastfeeding can continue with COVID-19 infection.
Further advice is available from the UK Drugs in Lactation Advisory Service .
10 February 2022