Is Fluoroestradiol F18 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 Fluoroestradiol F18. The text below is quoted from that source — it is not our own verdict.

Summary of use during breastfeeding

Information in this record refers to the use of fluoroestradiol F18 (18F-FES) as a diagnostic agent. No information is available on the clinical use of fluoroestradiol F18 during breastfeeding. The manufacturer recommends that mothers avoid breastfeeding for 4 hours after administration of fluoroestradiol F18. Nursing mothers should not work with radioactive substances used in PET scans in their workplace.[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

F18 is a positron emitter with a principal decay energy of 0.6335 MeV, annihilation photons of 0.511 MeV, and a physical half-life of 1.8 hours and 0.07% of an administered dose appears in breastmilk.[2] The maximum effective half-life is 0.89 hours.[3]

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.

“No published information” means the studies do not exist yet — not that Fluoroestradiol F18 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 “Fluoroestradiol F18” (fluoroestradiol_F18). 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.