Is Zanamivir safe while breastfeeding?

Here is what LactMed, the Drugs and Lactation Database published by the U.S. National Institute of Child Health and Human Development (NICHD), reports about Zanamivir. The text below is quoted from that source — it is not our own verdict.

Summary of use during breastfeeding

No information is available on the use of zanamivir during breastfeeding. One group of authors estimated that an exclusively breastfed 5 kg infant would receive about 0.075 mg daily in breastmilk after an inhaled maternal dose of 10 mg, which is less than 1% of the dose in older children. In addition, because zanamivir is poorly absorbed orally, it is not likely to reach the bloodstream of the infant in clinically important amounts.[1]

Effects on the breastfed infant

Relevant published information was not found as of the revision date.

Effects on milk supply

Relevant published information was not found as of the revision date.

Levels in milk

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.

Alternatives LactMed lists

“No published information” means the studies do not exist yet — not that Zanamivir is known to be harmful, and not that it is known to be safe. Your prescriber or pharmacist can weigh your baby's age and whether a better-studied alternative would do the same job. Worth asking before stopping a medicine you need.

Source: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Zanamivir” (LM717). LactMed on NCBI Bookshelf. LactMed is a registered trademark of the U.S. Department of Health and Human Services.

Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.