Montelukast selectively antagonizes leukotriene D_ (LTD_) at the cysteinyl leukotriene receptor, CysLT_, in the human airway. Montelukast inhibits the actions of LTD_ at the CysLT_ receptor, preventing airway edema, smooth muscle contraction, and enhanced secretion of thick, viscous mucus.
Montelukast, like zafirlukast, is a leukotriene receptor antagonist used as an alternative to anti-inflammatory medications in the management and chronic treatment of asthma and exercise-induced bronchospasm (EIB). Unlike zafirlukast, montelukast does not inhibit CYP2C9 or CYP3A4 and is, therefore, not expected to affect the hepatic clearance of drugs metabolized by these enzymes.
Side effects include headache, abdominal or stomach pain, cough, dental pain, dizziness, fever, heartburn, skin rash, stuffy nose, weakness or unusual tiredness.