Onset and duration of action of formoterol and tiotropium in patients with moderate to severe COPD.

Background: Chronic obstructive pulmonary disease (COPD) management guidelines recommend regular treatment with one or more long-acting bronchodilators for patients with moderate to severe COPD.

Objective: To compare the onset and duration of action of formoterol and tiotropium in patients with COPD.

Methods: This randomized, multicentre, open-label crossover study in 38 patients with COPD (mean age 64 years; mean FEV(1) 55% predicted) assessed the effect of 7 days of treatment with formoterol (12 microg b.i.d. via Foradil Aerolizer) vs. tiotropium (18 microg o.d. via Spiriva HandiHaler) on lung function measured over a period of 12 h after the first dose on day 1 and the last dose on day 8.

Results: The primary efficacy variable, FEV(1)-AUC during the first 2 h post-dose (FEV(1)-AUC(10-120 min)), was significantly higher for formoterol compared with tiotropium, with between-treatment differences of 124 ml (p = 0.016) after the first dose and 80 ml (p = 0.036) after 7 days' treatment in favour of formoterol. FEV(1) measured 12 h after inhalation did not differ statistically significantly between treatments. Adverse events occurred in 2 (5%) patients after treatment with formoterol and in 5 (12%) patients after treatment with tiotropium.

Conclusion: This study demonstrates faster onset of action and greater bronchodilation of formoterol vs. tiotropium for bronchodilation within the first 2 h of inhalation (FEV(1)-AUC(10-120 min)) and comparable bronchodilation 12 h post-inhalation in patients with moderate to severe COPD.