Is Montelukast safe while breastfeeding?

Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Montelukast. 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. Seven women were given a 10 mg dose of montelukast and provide milk samples before the dose and at 6 times over the next 12 hours. Average peak milk concentration of the drug were 9.74 mcg/L at an average of 4 hours after the dose. The average milk concentration was 5.3 mcg/L which resulted in an average daily infant dosage of 0.79 mcg/kg (range 0.4 to 1.4 mcg/kg daily) or 0.68% of the weight-adjusted maternal dosage.[ 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 Montelukast 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.