Verlukast is used primarily in the treatment of asthma as a leukotriene receptor antagonist. It helps reduce inflammation in the airways and prevents bronchoconstriction, making it effective for long-term asthma management. It is particularly useful in patients with allergic asthma or exercise-induced bronchospasm. Verlukast also helps improve lung function and reduce the frequency of asthma symptoms, allowing for better control of the condition with fewer rescue inhaler uses. Additionally, it may be used to manage other respiratory conditions involving leukotriene-mediated inflammation.