Montelukast belongs to a class of drugs known as leukotriene receptor antagonists. Montelukast is used to control and prevent symptoms caused by asthma (such as wheezing and shortness of breath). It can also be used to prevent exercise-induced bronchoconstriction (EIB).This drug works by blocking certain natural substances (leukotrienes) that may cause or worsen asthma and allergies. It helps make breathing easier by reducing swelling (inflammation) in the airways.