Leukotriene modifiers are a class of medications used primarily to manage asthma and allergic rhinitis. They work by blocking the action of leukotrienes, which are chemicals in the body that contribute to inflammation, bronchoconstriction, and mucus production. By inhibiting these substances, leukotriene modifiers help reduce airway swelling and improve breathing. Common examples of leukotriene modifiers include montelukast and zafirlukast. These medications are typically taken as oral tablets and can be used alongside other asthma treatments. They are particularly beneficial for patients who experience exercise-induced bronchoconstriction or have allergies that trigger asthma symptoms.