Montelukast sodium

It is acompetitive leukotriene antagonist .

It binds with high affinity to the ltd4 receptor ,inhibiting bronchoconstriction .cysteinyl leukotrienes are important proinflammatory mediators in aasthma 

They have been correlated with the pathophysiology of aasthma ,including airway edema, smoth muscle contraction , and altered cellular activity associated with the inflammatory process ,which contribute to the signs and symptoms of aasthma .

They also play an important role in aspirin induced aasthma.

Indication :

For the prophylaxis and chornic treatment of aasthma in adults and pediatric patients