Tiotropium versus Salmeterol for the Prevention of Exacerbations of COPD

Treatment guidelines recommend the use of inhaled long-acting bronchodilators to alleviate symptoms and reduce the risk of exacerbations in patients with moderate-to-very-severe chronic obstructive pulmonary disease (COPD) but do not specify whether a long-acting anticholinergic drug or a β(2)-agonist is the preferred agent. We investigated whether the anticholinergic drug tiotropium is superior to the β(2)-agonist salmeterol in preventing exacerbations of COPD.

In a 1-year, randomized, double-blind, double-dummy, parallel-group trial, we compared the effect of treatment with 18 μg of tiotropium once daily with that of 50 μg of salmeterol twice daily on the incidence of moderate or severe exacerbations in patients with moderate-to-very-severe COPD and a history of exacerbations in the preceding year.