MONTAIR 4 is a chewable tablet containing 4 milligrams of montelukast sodium. Montelukast is a leukotriene receptor antagonist used in children (typically aged 2-5 years) for the prevention and chronic treatment of asthma, the relief of symptoms of allergic rhinitis (both seasonal and perennial), and the acute prevention of exercise-induced bronchoconstriction. It works by blocking the action of leukotrienes, substances in the body that cause inflammation and narrowing of the airways,