Salmeterol is primarily used in the management of asthma and chronic obstructive pulmonary disease (COPD). It functions as a long-acting beta-2 adrenergic agonist, helping to relax the muscles in the airways and improve breathing. This makes it effective in preventing symptoms such as wheezing, shortness of breath, and chest tightness. It is often prescribed for regular use to maintain open airways and is typically combined with inhaled corticosteroids for better control of inflammation. Salmeterol is not intended for immediate relief of acute asthma attacks but is used as a maintenance treatment to reduce the frequency and severity of symptoms over time.