Zafirlukast and Breastfeeding

Summary of use during lactation

No published information is available on the use of zafirlukast during breastfeeding; however, manufacturer's data indicate that the dose in milk is low. Zafirlukast has been used in children as young as 12 months of age.[1] International guidelines consider that leukotriene receptor antagonists can be used during breastfeeding.[2,3]

Drug levels in milk and infant serum

Maternal Levels. Relevant published information was not found as of the revision date. The manufacturer reports that after administration of zafirlukast 40 mg twice daily to lactating women (number not reported), average steady-state milk concentrations were 50 mcg/L. Using these data, a fully breastfed infant would be expected to receive about 0.6% of the maternal weight-adjusted dosage. 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, Montelukast, Terbutaline, Theophylline

References

1. Berlin CM, Briggs GG. Drugs and chemicals in human milk. Semin Fetal Neonatal Med 2005;10:149-5915701580 PubMed
2. 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
3. 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