Is Propafenone 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 Propafenone. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Limited information indicates that maternal doses of propafenone up to 900 mg daily produce low levels in milk. If propafenone is required by the mother it is not a reason to discontinue breastfeeding. Until more data become available, propafenone should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant.
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. On the third postpartum day, one woman taking propafenone 300 mg orally 3 times daily had milk levels just before the morning dose of 32 and 47 mcg/L of propafenone and hydroxypropafenone, respectively. The authors estimated that a fully breastfed would receive a dose of propafenone and its metabolite of about 0.03% of the mother's weight-adjusted dosage.[1]
One mother (time postpartum not stated) took a single dose of propafenone 150 mg orally. The highest milk propafenone level was 37.4 mcg/L at 2 hours after the dose. By 6 hours after the dose, the drug was undetectable (<10 mcg/L). The highest milk 5-hydroxypropafenone level was 102 mcg/L at 2 hours after the dose. By 6 hours after the dose, the level was 19.8 mcg/L and by 12 hours it was undetectable (<10 mcg/L) in milk. The authors estimated that an exclusively breastfed infant would receive 0.1% of the maternal weight-adjusted dosage of propafenone as drug and metabolite.[2]
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 Propafenone 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 “Propafenone” (LM229). 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.