Tiotropium vs. Salmeterol to Prevent COPD Exacerbations

Both inhaled long-acting β-agonists and inhaled anticholinergic agents are first-line treatments for patients with moderate-to-severe chronic obstructive pulmonary disease (COPD). To determine which is better, 7400 COPD patients were randomized to 1-year courses of inhaled therapy with either the anticholinergic agent tiotropium (Spiriva) or the β-agonist salmeterol (Serevent) in a multicenter, double-blind, international study. All enrollees had moderate-to-severe COPD (post-bronchodilator forced expiratory volume in 1 second [FEV₁] to forced vital capacity [FVC] ≤70%, and FEV₁ ≤70% predicted) and had experienced at least one exacerbation (i.e., need for systemic steroids, antibiotics, or hospitalization) during the previous year. The study was funded by the manufacturer of tiotropium, and several authors were employees of that company.

The time to first exacerbation was significantly longer with tiotropium than with salmeterol (187 vs. 145 days). Tiotropium recipients, compared with salmeterol recipients, had significantly lower annual rates of exacerbations (0.64 vs. 0.72) and hospitalizations (0.09 vs. 0.13). Better outcomes with tiotropium were noted regardless of background use of inhaled steroids. Rates of adverse effects were similar in the two groups.