Is Mefloquine 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 Mefloquine. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Very small amounts of mefloquine are excreted in breastmilk; the amount of drug is not sufficient to harm the infant nor is the quantity sufficient to protect the child from malaria. Breastfeeding infants should receive the recommended dosages of mefloquine.[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. 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: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Mefloquine” (LM294). 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.