Background: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends long-acting bronchodilators as first-line maintenance treatment for patients with chronic obstructive pulmonary disease (COPD). A study was conducted comparing the long-acting anticholinergic tiotropium with the long-acting beta-agonist salmeterol to confirm the significant improvements in daytime bronchodilator efficacy seen with tiotropium in previous studies.
Methods: Randomized, double-blind, double-dummy, parallel-group study, comparing daytime bronchodilator efficacy of tiotropium 18 mcg once daily with salmeterol 50 mcg twice daily in patients with COPD. Serial spirometry was performed over 12 h after 12 weeks of treatment. Co-primary endpoints were average (over 12 h) and peak FEV1 at 12 weeks.
Results: 653 patients were randomized (328 tiotropium, 325 salmeterol): mean age 64 years; 66% male; mean baseline FEV1 1.05 l (37.7% predicted). After 12 weeks, the average post-dose FEV1 over 12 h was significantly higher with tiotropium compared with salmeterol (167 vs. 130 mL, respectively, p=0.03), as was peak FEV1 (262 vs. 216 ml, respectively, p=0.01). The average FEV1 responses from 0-6 h and 6-12 h were higher in the tiotropium group compared with salmeterol (p<0.05). Peak and average FVC were significantly higher with tiotropium compared with salmeterol (p<0.01). Morning pre-dose FEV1 responses were not significantly different; however, tiotropium demonstrated a significantly higher pre-dose FVC than salmeterol (p<0.05).
Conclusion: Tiotropium demonstrated significantly greater post-dose improvements in spirometric parameters compared with salmeterol. These improvements were sustained over 12 h.