Salmeterol stimulates intracellular adenyl cyclase, the enzyme that catalyses the conversion of ATP to cyclic-3',5'-adenosine monophosphate (cAMP) resulting in relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from mast cells.
Used in the treatment of obstructive airway diseases.
Chronic asthma: 50 mcg bid, up to 100 mcg bid if necessary, w/ an inhaled corticosteroid.
COPD: 50 mcg bid.
Prophylaxis of exercise-induced asthma: 50 mcg at least 30 min prior to exercise.
Adverse drug reactions: cough, headache, musculoskeletal pain, throat irritation.