About Montelukast Leukotriene(CysLT1) Receptor Antagonist, Antiinflammatory,antiasthma. Mechanism of Action of Montelukast Montelukast is competitively and selectively antagonizes CysLT1 receptor (leukotrienes receptor) mediated Bronchoconstriction.Montelukast inhibits physiologic actions of LTD 4 at the CysLT1 receptor without any agonist activity. Indications for Montelukast Asthma. Interactions for Montelukast Barbiturates & Primidone: Plasma concentration of montelukast is reduced by phenobarbital.