Is Quinidine safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Quinidine. This is a summary of that source — not our own verdict.
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. In one case report, a quinidine milk level of 6.4 mg/L was reported 3 hours after a dose while taking 600 mg every 8 hours orally of a sustained-release quinidine sulfate preparation (Quninidex). In the same patient, a random milk level of 8.2 mg/L was also measured.[ 1 ] Data from this case indicate that a breastfed infant would receive about 3 to 4% of the maternal weight-adjusted dosage of quinidine. 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 Quinidine 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: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.