Montelukast

What it is and how it works

Mechanism of Action The cysteinyl leukotrienes (LTC 4 , LTD 4 , LTE 4 ) are products of arachidonic acid metabolism and are released from various cells, including mast cells and eosinophils. These eicosanoids bind to cysteinyl leukotriene (CysLT) receptors. The CysLT type-1 (CysLT 1 ) receptor is found in the human airway (including airway smooth muscle cells and airway macrophages) and on other pro-inflammatory cells (including eosinophils and certain myeloid stem cells). CysLTs have been correlated with the pathophysiology of asthma and allergic rhinitis.

Mechanism class: Leukotriene Receptor Antagonists

Indications

Montelukast sodium chewable tablets are a leukotriene receptor antagonist indicated for: • Prophylaxis and chronic treatment of asthma in patients 2 years of age and older . • Acute prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older . • Relief of symptoms of allergic rhinitis (AR): seasonal allergic rhinitis (SAR) in patients 2 years of age and older, and perennial allergic rhinitis (PAR) in patients 2 years of age and older. Reserve use for patients who have an inadequate response or intolerance to alternative therapies . Asthma Montelukast sodium chewable tablets are indicated for the prophylaxis and chronic treatment of asthma in adults and pediatric patients 2 years of age and older. Exercise-Induced Bronchoconstriction (EIB) Montelukast sodium chewable tablets are indicated for prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older.

Dosage and administration (summary)

Administration (by indications): • Asthma : Once daily in the evening for patients 2 years and older. • Acute prevention of EIB : One tablet at least 2 hours before exercise for patients 6 years of age and older. • Seasonal allergic rhinitis : Once daily for patients 2 years and older. • Perennial allergic rhinitis : Once daily for patients 2 years and older. Dosage (by age) : • 15 years and older: one 10-mg tablet. • 6 to 14 years: one 5-mg chewable tablet. • 2 to 5 years: one 4-mg chewable tablet. Patients with both asthma and allergic rhinitis should take only one dose daily in the evening . Asthma Montelukast sodium should be taken once daily in the evening.

Contraindications

• Hypersensitivity to any component of this product. • Hypersensitivity to any component of this product .

Warnings and precautions

• Do not prescribe montelukast sodium to treat an acute asthma attack . • Advise patients to have appropriate rescue medication available . • Inhaled corticosteroid may be reduced gradually. Do not abruptly substitute montelukast sodium for inhaled or oral corticosteroids . • Patients with known aspirin sensitivity should continue to avoid aspirin or non-steroidal anti-inflammatory agents while taking montelukast sodium . • Systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, has been reported.

Pregnancy

Pregnancy Risk Summary Available data from published prospective and retrospective cohort studies over decades with montelukast use in pregnant women have not established a drug-associated risk of major birth defects .

Storage and supply

Product: 50090-7920 NDC: 50090-7920-0 30 TABLET, CHEWABLE in a BOTTLE NDC: 50090-7920-1 90 TABLET, CHEWABLE in a BOTTLE

Source: Montelukast Sodium (Montelukast Sodium) — US FDA prescribing information, 2026-03-05, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.