Pretreatment with inhaled procaterol improves symptoms of dyspnea and quality of life in patients with severe COPD

BACKGROUND The clinical efficacy of short-acting β(2)-agonists administered before performing daily activities in chronic obstructive pulmonary disease (COPD) is unclear. The aim of this study was to investigate the clinical effect of supplementary inhaled procaterol hydrochloride in patients with COPD. METHODS Thirty outpatients with moderate to severe COPD (Stage II-IV) regularly using inhaled tiotropium bromide alone and with dyspnea during daily activities were enrolled. Subjects self-administered 20 μg of inhaled procaterol before daily activities no more than four times daily. Dyspnea symptom scores, St George's Respiratory Questionnaire (SGRQ) activity domains, impulse oscillometry system parameters, and pulmonary function tests were recorded at the beginning and end of the 2-week study. RESULTS At baseline, more than 80% of subjects reported dyspnea when walking up a slope (100.0%), climbing stairs (100.0%), gardening (93.3%), walking on flat ground (90.0%), bathing (86.7%), getting on a bus or train (83.3%), and changing clothes (80.0%). After 2 weeks, subjects with Stage III symptoms had significantly improved dyspnea scores on walking up a slope (P = 0.047), climbing stairs (P = 0.014), gardening (P = 0.034), walking on flat ground (P = 0.006), getting on a bus or train (P = 0.039), and changing clothes (P = 0.045). Both symptom and activity SGRQ domains improved significantly in subjects with Stage III symptoms (P = 0.036 and P = 0.028, respectively). Resistance of small airways and low-frequency reactance area values improved significantly in subjects with Stage III symptoms (P = 0.003 and P = 0.004, respectively). No significant changes were found in pulmonary function tests. CONCLUSION Use of supplementary inhaled procaterol before performing daily activities improved dyspnea symptoms in subjects with Stage III COPD.