ATC Group: R03DC Leukotriene receptor antagonists

Montelukast is an orally active compound which binds with high affinity and selectivity to the CysLT1 receptor. Τhe CysLT type-1 (CysLT₁) 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.

Zafirlukast is a selective and competitive receptor antagonist of leukotriene D₄ and E₄ (LTD₄ and LTE₄), components of slowreacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma.