Formoterol Hemifumarate is primarily used as a bronchodilator in the treatment of asthma and chronic obstructive pulmonary disease (COPD). It works by relaxing the muscles in the airways, which helps to improve breathing and reduce symptoms such as wheezing, shortness of breath, and coughing. This medication is often included in long-acting beta-agonist (LABA) inhalers, either alone or in combination with corticosteroids, to provide sustained relief over an extended period. It is particularly effective in managing nocturnal asthma and exercise-induced bronchoconstriction. Patients typically use it as a maintenance treatment to prevent asthma attacks rather than for immediate relief during an acute episode. Regular use helps in maintaining open airways and improving overall lung function, thereby enhancing the quality of life for individuals with chronic respiratory conditions.