Montelukast and Breastfeeding

Summary of use during lactation

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]

Drug levels in milk and infant serum

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.

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

Beclomethasone, Cromolyn, Terbutaline, Theophylline, Zafirlukast

References

1. Middleton PG, Gade EJ, Aguilera C, et al. ERS/TSANZ Task Force Statement on the management of reproduction and pregnancy in women with airways diseases. Eur Respir J 2020;55:190120831699837 PubMed
2. Bendien SA, de Kruif MD, Feitsma H, et al. Summary of the Dutch Multidisciplinary Practice Guideline on Asthma and Pregnancy. J Allergy Clin Immunol Pract 2024;12:1751-6238513758 PubMed
3. Datta P, Rewers-Felkins K, Baker T, et al. Transfer of montelukast into human milk during lactation. Breastfeed Med 2017;12:54-728002678 PubMed