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

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.

Alternate 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;10:149-59 [PubMed: 15701580]

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;55:1901208 [PubMed: 31699837]

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;12:1751-62 [PubMed: 38513758]

Substance Name

Zafirlukast

CAS Registry Number

107753-78-6

Drug Class

Breast Feeding

Lactation

Milk, Human

Anti-Asthmatic Agents

Leukotriene Antagonists