Montelukast is a leukotriene receptor antagonist drug.
It is well absorbed orally, highly plasma protein-bound, and metabolized by the CYP2C9 enzyme. Has a plasma t½ of
is 3–6 hours.
Mechanism of action.
- It competitively antagonizes cysLT1 receptor-mediated bronchoconstriction and airway mucus secretion.
- This leads to the relaxation of bronchial smooth muscles.
Clinical uses.
- Prophylactic therapy for mild-to-moderate asthma and as an alternative to inhaled glucocorticoids.
- The drug cannot be used to terminate asthma episodes.
- It is modestly effective in aspirin-induced and exercise-induced asthma but is of no value in COPD.
- Symptomatic relief of seasonal allergic rhinitis and urticaria.
Adverse effects.
- Headache, fever, and rashes.
- Eosinophilia and neuropathy. Few cases of Churg-Strauss syndrome
(vasculitis with eosinophilia) have been reported.
- Increased bleeding tendencies.
- Hallucination, restlessness, irritability.
- Dyspepsia, diarrhea, and abdominal pain.
Contraindication.
- Acute asthma attack including status asthmaticus.
- Monitor pregnancy and lactation.
Drug interaction.
- Montelukast is an inhibitor of the drug-metabolizing enzyme CYP2C8 hence interacting with phenytoin, aspirin, and phenobarbitone.
