Leukotrine inhibitors is a new type of medication used to treat severe cases of asthma which have persisted for extended periods of time without responding to any other form of treatment. They can also be used to treat allergic rhinitis, the precursor of occupational asthma.

Leukotrienes are created by the body's immune system as an involuntary response to numerous types of triggers, including the allergens which cause asthma. They can cause bronchoconstriction, resulting in tightening of the respiratory muscles and inflammation of the bronchial tubes, making breathing difficult. Thus, by inhibiting the leukotreines, asthma and various other allergic conditions can be treated easily.

For dealing with exercise-induced asthma, leukotriene inhibitors are much better than placebo, and at least as good as long-acting β2-agonist bronchodilators. When treating allergic rhinitis, their effectiveness is comparable to that of antihistamines, but intranasal steroids are a better option in such cases. Leukotriene inhibitors can also be used to treat cases of asthma which cannot be treated by aspirin, but this particular use of them is not yet widespread. Also, one of the greatest advantage of using them is the fact that they invoke very few noticeable side-effects in most people.