Is Mefloquine safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Mefloquine. 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. Two women who were 2 to 3 days postpartum were given mefloquine 250 mg orally. In one woman who provided milk samples periodically for 56 days, the milk mefloquine level declined from 53 to 32 mcg/L over this period. The average half-life in breastmilk for the 2 women was 16.6 days. The authors estimated that an exclusively breastfed infant would receive an average of 3.8% of the maternal weight-adjusted dosage of mefloquine after a single dose. However, this value could be higher with weekly doses because of accumulation.[ 2 ] A physiologically based pharmacokinetic model has been developed that adequately predicts mefloquine excretion into breastmilk.[ 3 ] 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 Mefloquine 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.