Improvement of pulmonary function and dyspnea by tiotropium in COPD patients using a transdermal β2-agonist

BackgroundA combination of bronchodilators may be effective in the treatment of chronic obstructive pulmonary disease (COPD). We examined the effect of adding a long-acting anti-cholinergic agent (tiotropium) to a transdermal-type β2-agonist (tulobuterol) on dyspnea as well as pulmonary function.MethodsIn a multicentre, randomized, parallel design study, 60 COPD patients treated with the transdermal β2-agonist tulobuterol were divided into a tiotropium added group (Tulo+Tio group, n=40n=40) or transdermal β2-agonist tulobuterol alone group (Tulo group, n=20n=20), and then treated for 4 weeks after a 2 week run-in period. Pulmonary function and a dyspnea (Medical Research Council (MRC)) scale were assessed before and after the treatment. Daily peak expiratory flow (PEF) monitoring was also performed.ResultsAfter 4 weeks, the Tulo+Tio group showed a significant increase in pulmonary function compared with the Tulo group; ΔFVC (0.31±0.06 L vs. 0.06±0.05 L, p< 0.01), ΔFEV1 (0.15±0.03 L vs. −0.02±0.02 L, p<0.0001), and ΔPEF (41.0±5.1 L/min vs. 0.5±3.5 L/min, p<0.0001). The MRC dyspnea scale was also significantly improved in Tulo+Tio, but not in Tulo group.ConclusionThese results suggest that tiotropium caused a significant improvement in both pulmonary function and dyspnea in COPD patients already treated with the transdermal β2-agonist tulobuterol.