Answer
It is unknown whether baloxavir marboxil or its active metabolite, baloxavir, passes into human breast milk, and a risk to newborns or infants cannot be excluded.
Sources for this answer
- Xofluza 40 mg & 80 mg film coated tabletsRoche Products Limited · emc · SmPC §4.6 Fertility, pregnancy and lactation · Version 9Document updated
Sources checked