Gemilukast is an orally active and potent dual cysteinyl leukotriene 1 and 2 receptors (CysLT 1 and CysLT 2 ) antagonist, with IC 50 s of 1.7, 25 nM for human CysLT 1 and CysLT 2 , respectively. In Vitro Gemilukast is an orally active and potent dual cysteinyl leukotriene 1 and 2 receptors (CysLT 1 and CysLT 2 ) antagonist, with IC 50 s of 1.7, 25 nM for human CysLT 1 and CysLT 2 , respectively. Both Gemilukast (ONO-6950) and montelukast inhibit human CysLT 1 receptor-mediated calcium response with IC 50 values of 1.7 and 0.46 nM, respectively. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Gemilukast at 0.03 to 10 mg/kg, p.o. dose-dependently attenuates LTC4-induced bronchoconstriction with almost complete inhibition at 3 mg/kg. The inhibitory effect of Gemilukast on LTC4-induced bronchoconstriction is significantly stronger than that of montelukast at the dose of 1 mg/kg or more. Gemilukast (0.03 to 1 mg/kg, p.o.) dose-dependently attenuates LTD4-induced airway vascular hyperpermeability with complete inhibition at 0.3 mg/kg. Gemilukast at 0.1 to 3 mg/kg, p.o. dose-dependently inhibits OVA-induced bronchoconstriction. The inhibitory effect of Gemilukast at 3 mg/kg is significantly greater than that of montelukast alone and comparable to that of combination therapy with montelukast and BayCysLT2RA. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:CysLT 1 1.7 nM (IC 50 , in human) CysLT 2 25 nM (IC 50 , in human)