Comparison of the acute effect of tiotropium versus a combination therapy with single inhaler budesonide/formoterol on the degree of resting pulmonary hyperinflation

In 20 COPD patients ( FEV1 {less-than or slanted equal to} 65 % predicted, IC < 80 % predicted), we evaluated changes in the degree of pulmonary hyperinflation after acute administration of tiotropium 18 μ g or budesonide/formoterol 320 / 9 μ g. The study consisted of a screening visit and two study days separated by at least one week. Functional parameters were measured before and 30, and 120 min after inhalation of single study drug. Both tiotropium and budesonide/formoterol induced significant changes in functional parameters after 30 and 120 min. However, the impact of tiotropium on the degree of pulmonary hyperinflation was larger than that of budesonide/formoterol, although only differences in IC and TGV between the two treatments were significant ( P < 0.05 ), at least after 120 min, whereas those in RV were not significant. The documentation that tiotropium is able to modify IC even after an acute administration indicates its capacity of influencing expiratory flow limitation in a very fast manner and this is an important finding. In fact, changes in IC after bronchodilators in patients with COPD with expiratory flow limitation at rest may represent an objective tool for prescribing these drugs to attain symptomatic improvement and better quality of life, even in the absence of a significant increase in FEV1.