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

Summary: Background: Chronic obstructive pulmonary disease (COPD) patients are thought to have limited bronchodilator response, determined by changes in forced expiratory volume in 1s (FEV₁). In this study, we assessed bronchodilator response in patients with COPD using not only FEV₁ 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 FEV₁ 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: FEV₁ (57–59%). Similar results were seen for IC (50–61%) and FVC (57–67%) using the same improvement criteria. The time to ≥15% FEV₁ 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% FEV₁ 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. [ABSTRACT FROM AUTHOR]