Montelukast in Eosinophilic Asthma
Montelukast is not a preferred treatment for eosinophilic asthma and should be considered only as an alternative therapy for mild persistent asthma when inhaled corticosteroids cannot be used. 1
Role of Montelukast in Asthma Treatment
- Montelukast (Singulair) is a leukotriene receptor antagonist (LTRA) that interferes with the pathway of leukotriene mediators released from mast cells, eosinophils, and basophils 1
- It is FDA-approved for long-term management of asthma in adults and children 12 months and older, but not for immediate relief of acute asthma attacks 2
- Montelukast works by blocking leukotrienes, which are inflammatory mediators involved in asthma pathophysiology 2
Efficacy in Eosinophilic Asthma
- Inhaled corticosteroids (ICS) are more effective than montelukast in reducing airway eosinophilia and improving lung function in patients with eosinophilic asthma 3
- While montelukast can reduce sputum eosinophils (from 7.5% to 3.9% in one study), its effect is less robust than that of ICS 4
- In patients already on high-dose corticosteroid therapy with persistent sputum eosinophilia, adding montelukast does not provide additional reduction in airway eosinophilia 5
- Montelukast's effect on reducing eosinophilic inflammation may be maximal at 1 week but is not consistently maintained over longer periods (8 weeks) 3
Treatment Algorithm for Asthma with Eosinophilia
- First-line therapy: Inhaled corticosteroids are the most consistently effective long-term control medication for persistent asthma, including eosinophilic phenotypes 1
- Alternative therapy: Montelukast may be considered as an alternative (but not preferred) therapy for patients requiring step 2 care (mild persistent asthma) who cannot use ICS 1, 6
- Add-on therapy: For moderate to severe persistent asthma, montelukast can be used as adjunctive therapy with ICS, but is not the preferred adjunctive therapy compared to long-acting beta-agonists (LABAs) 1
- Special situations: Montelukast may be particularly effective in specific asthma phenotypes such as exercise-induced asthma, asthma with allergic rhinitis, asthma in obese patients, and aspirin-induced asthma 7
Practical Considerations and Precautions
- Montelukast should be taken once daily, in the evening for asthma management 2
- It should not be used for immediate relief of asthma attacks; patients should always have rescue medication available 2
- Patients should continue taking montelukast daily even when asymptomatic 2
- Neuropsychiatric events have been reported with montelukast use, including agitation, depression, and suicidal thinking; patients and prescribers should be alert for these potential adverse effects 2
- In rare cases, patients with asthma on montelukast therapy may present with systemic eosinophilia, sometimes with features consistent with Churg-Strauss syndrome 2
Monitoring Response
- If asthma symptoms worsen or if increased use of rescue medication is needed while on montelukast, patients should contact their physician promptly 2
- Patients should not decrease the dose or stop taking other anti-asthma medications unless instructed by a physician 2
- For patients with eosinophilic asthma who do not respond adequately to montelukast, consider switching to or adding other controller medications 1