Levocetirizine is 3rd generation anti histamine which blocks H1 receptors in eyes, nose, skin & bronchi. Levocetirizine is highly selective H1 receptor antagonist hence least sedative. Twice as potent as Cetirizine in blocking histamine (H1) receptor..
Montelukast is a selective and orally active leukotriene receptor antagonist which inhibits the cysteinyl leukotriene 1 receptor. Montelukast is effective and well-tolerated preventive treatment for asthma and allergic rhinitis in adults and children.