The Basics
What is Zafirlukast?
Used to prevent asthma symptoms by blocking the action of certain natural substances that cause swelling and tightening of the airways.
Brand names for Zafirlukast
Accolate
How Zafirlukast is classified
Anti-Asthmatic Agents, Leukotriene Antagonists
Zafirlukast During Pregnancy
Zafirlukast pregnancy category
Category BNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Zafirlukast while pregnant
No teratogenicity was observed at oral doses up to 1600 mg/kg/day in mice (approximately 160 times the maximum recommended daily oral dose in adults on a mg/m² basis), up to 2000 mg/kg/day in rats (approximately 410 times the maximum recommended daily oral dose in adults on a mg/m² basis) and up to 2000 mg/kg/day in cynomolgus monkeys (which resulted in approximately 20 times the exposure to drug plus metabolites compared to that from the maximum recommended daily oral dose in adults based on comparison of the AUC values). At an oral dose of 2000 mg/kg/day in rats, maternal toxicity and deaths were seen with increased incidence of early fetal resorption. Spontaneous abortions occurred in cynomolgus monkeys at the maternally toxic oral dose of 2000 mg/kg/day. There are no adequate and well-controlled trials in pregnant women. Because animal reproductive studies are not always predictive of human response, ACCOLATE should be used during pregnancy only if clearly needed.
Taking Zafirlukast While Breastfeeding
What are recommendations for lactation if you're taking Zafirlukast?
No published information is available on the use of zafirlukast during breastfeeding; however, manufacturer’s data indicate that the dose in milk is low. If zafirlukast is required by the mother, it is not a reason to discontinue breastfeeding. However, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. Zafirlukast has been used in children as young as 12 months of age.[1]
Maternal / infant drug levels
No published information is available on the use of zafirlukast during breastfeeding; however, manufacturer’s data indicate that the dose in milk is low. If zafirlukast is required by the mother, it is not a reason to discontinue breastfeeding. However, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. Zafirlukast has been used in children as young as 12 months of age.[1]
Possible effects of Zafirlukast on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Zafirlukast
Beclomethasone, Cromolyn, Montelukast, Terbutaline, Theophylline.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Berlin CM, Briggs GG. Drugs and chemicals in human milk. Semin Fetal Neonatal Med. 2005;10:149-59. PMID: 15701580
2. Anon. Accolate Package Insert. AstraZeneca Pharmaceuticals. Wilmington DE. 2011.
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
