Is Montelukast (Singulair) safe to use during pregnancy?

Montelukast Safety During Pregnancy

Montelukast (Singulair) is safe to use during pregnancy, particularly for women with recalcitrant asthma or allergic rhinitis who have shown a favorable response prior to pregnancy. 1

Safety Profile

• Montelukast has a Pregnancy Category B classification from the FDA, indicating:

  • No teratogenicity observed in animal studies at doses far exceeding human therapeutic doses 2
  • No evidence of increased congenital malformations in human studies 2
  • The drug crosses the placenta, but available data are reassuring 2

• Multiple clinical guidelines support its use during pregnancy:

  • The American College of Allergy, Asthma and Immunology practice parameter states that "Montelukast is a safe treatment for allergic rhinitis during pregnancy" 3
  • The European Respiratory Society and Thoracic Society of Australia and New Zealand recommend montelukast for recalcitrant asthma during pregnancy 1

Clinical Evidence

• A prospective, comparative study of 180 montelukast-exposed pregnancies found no increase in the rate of major malformations above the baseline risk 4

  • Lower birth weight was noted in the montelukast group, but this was likely associated with the severity of maternal asthma rather than medication use 4

• A Danish population-based study of over 750,000 pregnancies found no significant increase in congenital anomalies with montelukast exposure 5

  • While preterm birth and maternal complications were higher in the montelukast group, these risks are known to be associated with maternal asthma itself 5

Clinical Application

For pregnant women with asthma:

1. Inhaled corticosteroids (particularly budesonide) remain first-line therapy 1
2. Montelukast should be considered when:
   • Asthma is not adequately controlled with inhaled medications alone
   • The patient has demonstrated a favorable response to montelukast before pregnancy 1

For pregnant women with allergic rhinitis:

1. Intranasal corticosteroids are preferred as first-line therapy 1
2. Montelukast is a safe alternative, especially for those who:
   • Cannot tolerate or do not respond to intranasal corticosteroids
   • Have shown good response to montelukast before pregnancy 3

Important Considerations

• Untreated or poorly controlled asthma during pregnancy poses greater risks to mother and fetus than medication use 1
• Montelukast should be avoided for chronic rhinosinusitis maintenance during pregnancy (saline rinses and topical corticosteroids preferred) 1
• Healthcare providers are encouraged to report prenatal exposure to montelukast to the Pregnancy Registry maintained by the manufacturer 2

Breastfeeding Considerations

• Montelukast is excreted in breast milk, but benefits of breastfeeding generally outweigh risks 1
• To minimize infant exposure, consider breastfeeding before taking the medication 1

Human Medical Consultant