Bronchodilators for hyperinflation in COPD associated with biomass smoke: clinical trial

Abstract

Introduction: The efficacy of long-acting bronchodilators for COPD associated with biomass (BE-COPD) has not been properly evaluated.

Objective: To determine the acute effect of indacaterol (IND) 150 μg q.d and tiotropium (TIO) 18 μg q.d. on lung hyperinflation, walking distance (WD) and dyspnea during the six-minute walking test (6MWT) in moderate BE-COPD at 30, 60 and 240 mins post-drug administration.

Design: Randomized, controlled, open-level, crossover noninferiority clinical trial. Forty-two women with BE-COPD were randomly assigned to a bronchodilator sequence: IND-TIO or vice versa.

Results: There were statistically significant changes over time in inspiratory capacity (IC) (p<0.0001), FEV₁ (p<0.0001) and FVC (p<0.0001) when IND was used. When TIO was administered, an increase over all time periods was observed only for FEV₁ (p<0.0001) and FVC (p<0.0001), whereas for IC an increase was observed only at 30 mins and 24 hrs after TIO administration. We did not find clinically significant increases in WD and dyspnea after the administration of both bronchodilators.

Conclusion: Both IND and TIO showed significant and fast onset improvement in hyperinflation. Therefore, either of them may be recommended as a first line of treatment for COPD associated with BE-COPD.

Keywords: biomass exposure; indacaterol; inspiratory capacity; six-minute walking test; spirometry; tiotropium.

Figure 1

Study design and patient´s allocation of the 2-period cross-over sequences. During both visit 1 and visit 2, the pulmonary function tests measurements were done before and 30, 60, 240 mins, 23:10 and 23:45 hrs after a single-dose of the corresponding long-acting bronchodilator. Abbreviations: IC, inspiratory capacity; 6MWT, 6-minute walking test; IND, indacaterol; TIO, tiotropium.

Figure 2

Flowchart of subject recruitment.

Figure 3

Significant increases over all time periods were observed in IC (p<0.0001), after IND was administered. An increase was observed for IC only at 30 mins and 24 hrs after TIO administration. No significant differences were observed among TIO and IND.

Figure 4

Trough FEV₁, FVC and IC after administration a single dose of indacaterol or tiotropium. FEV1 and FVC increased whereas IC decreased with both bronchodilators. p<0.001. However, there were no differences between TIO and IND.