Summary of use during lactation
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]
Drug levels in milk and infant serum
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.
Effects in breastfed infants
Relevant published information was not found as of the revision date.
Effects on lactation and breastmilk
Relevant published information was not found as of the revision date.
Alternative drugs to consider
Atovaquone and Proguanil, Doxycycline, Chloroquine
References
- Malaria. In: Centers for Disease Control and Prevention. CDC Yellow Book 2024: Health Information for International Travel. 2024. https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/malaria#treatment
- Edstein MD, Veenendaal JR, Hyslop R. Excretion of mefloquine in human breast milk. Chemotherapy 1988;34:165-9.3262044 PubMed
- Almond LM, Abduljalil K, Pansari A, et al. PBPK-led assessment of antimalarial drug concentrations in breastmilk: A strategy for optimal use of prediction methods to guide decision making in an understudied population. CPT Pharmacometrics Syst Pharmacol 2025;14:738–50.39930940 PubMed
Source: Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, NCBI Bookshelf. Check LactMed for the most recent revision.
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