Bronchodilator responsiveness and onset of effect with budesonide/formoterol pMDI in COPD.

Background: Chronic obstructive pulmonary disease (COPD) patients are thought to have limited bronchodilator response, determined by changes in forced expiratory volume in 1s (FEV(1)). In this study, we assessed bronchodilator response in patients with COPD using not only FEV(1) but also changes in lung volume expressed as forced vital capacity (FVC) and inspiratory capacity (IC). We also evaluated the speed of onset of bronchodilation.
Methods: Data were from 2 randomized, double-blind, placebo-controlled studies (6-months [NCT00206154]; 12-months [NCT00206167]) in patients with moderate to very severe COPD.
Treatments: twice daily budesonide/formoterol pressurized metered-dose inhaler (pMDI) 320/9μg, budesonide/formoterol pMDI 160/9μg, formoterol dry powder inhaler (DPI) 9μg, placebo.
Results: The percentage of patients with FEV(1) improvement (≥12% and ≥200mL; American Thoracic Society [ATS] criterion) was 34-39% post-albuterol (screening). On day of randomization (DOR), a larger proportion receiving formoterol-containing treatment exhibited reversibility within 60min: FEV(1) (57-59%). Similar results were seen for IC (50-61%) and FVC (57-67%) using the same improvement criteria. The time to ≥15% FEV(1) improvement on DOR was 5.0, 4.8, and 7.3min for budesonide/formoterol 320/9, budesonide/formoterol 160/9, and formoterol, respectively. Time to ≥15% FEV(1) improvement was better maintained with budesonide/formoterol than formoterol at treatment end (6 and 12 months).
Conclusions: Most patients with moderate to very severe COPD exhibit ATS-defined bronchodilator reversibility based on flow and lung volume measures after budesonide/formoterol pMDI or formoterol treatment. Budesonide/formoterol pMDI also has a rapid (within 5min) onset of bronchodilation that is maintained over time compared with formoterol alone.
(Copyright © 2011. Published by Elsevier Ltd.)