Bronchodilator efficacy of tiotropium-formoterol via single pressurized meter dose inhaler (pMDI) versus tiotropium alone in COPD.

BACKGROUND: Bronchodilators form the main stay of treatment for COPD. When symptoms are not adequately controlled with one bronchodilator, addition of another bronchodilator is recommended. We have recently developed a combination of tiotropium and formoterol in a single pressurized metered dose inhaler (pMDI) (Cipla Ltd., India). The aim of this study was to compare the bronchodilator effects of a single dose of 18 mcg of tiotropium versus a single dose of a combination of 18 mcg tiotropium plus 12 mcg formoterol administered via a pMDI in subjects with moderate-to-severe COPD.

STUDY DESIGN: 44 COPD subjects were enrolled in this randomized, double-blind, multi-centre, cross-over study. 18 mcg tiotropium and 18 mcg tiotropium plus 12 mcg formoterol were administered via pressurized metered dose inhalers on two separate days. FEV(1), FVC and Inspiratory capacity (IC) were measured before, 15, 30 min, 1, 2, 3, 4, 6, 8, 12 and 24 h after the study drugs were administered.

RESULTS: Compared with tiotropium alone, a combination of tiotropium plus formoterol showed a faster onset of bronchodilator response (p < 0.01 for FEV(1) and FVC), a greater mean maximum change in FEV(1) (p = 0.01) and FVC (p = 0.008) and greater AUC(0-24h) values for FEV(1), FVC and IC. Trough FEV(1) and FVC values were also greater in the combination group.

CONCLUSION: A combination of tiotropium plus formoterol administered via a single inhaler produced a superior bronchodilator response than tiotropium alone over a period of 24 h.