Used in the treatment of reversible airway obstruction due to asthma or chronic obstructive pulmonary disease (COPD). Recently revised recommendations for management of asthma recommend that rapid-acting inhaled beta-agonist bronchodilators (not salmeterol) be reserved as acute relievers of bronchospasm; repeated or chronic use indicates the need for additional long-term control agents, including inhaled corticosteroids, mast cell stabilizers, and long-acting bronchodilators (oral theophylline or beta-agonists) and leukotriene modifiers (montelukast, zafirlukast).