Is Montelukast 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 Montelukast. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Very low levels of montelukast appear in breastmilk. Montelukast is approved for use in children as young as 6 months of age and has been used in neonates in dosages far greater than the amounts in breastmilk. Amounts ingested by the infant would not be expected to cause any adverse effects in breastfed infants. International guidelines consider that leukotriene receptor antagonists can be used during breastfeeding.[1,2]
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
Montelukast in pregnancy
LactMed covers breastfeeding only. For what the NHS and the US prescribing label say about pregnancy, see:
“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: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Montelukast” (LM600). 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.