Drug Levels and Effects:

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:

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 mefloqine 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]

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.

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.

Alternate Drugs to Consider:



1. Arguin PM, Steele SF. Chapter 2. The pre-travel consultation. Malaria. In. Centers for Disease Control and Prevention. CDC Health Information for International Travel 2010. Atlanta: U.S. Department of Health and Human Services, Public Health Service. 2009.
2. Edstein MD, Veenendaal JR, Hyslop R. Excretion of mefloquine in human breast milk. Chemotherapy (Basel). 1988;34:165-9. PMID:3262044

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antiinfective Agents

  • Antimalarials

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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