Exercise endurance times in chronic obstructive pulmonary disease (COPD) patients are not significantly improved by the use of simultaneous tiotropium/olodaterol therapy compared with tiotropium monotherapy, but dual treatment can result in reduced lung hyperinflation, according to new research published in the European Respiratory Journal.
The research is accompanied by an editorial from Dr Henrik Watz, also published in the ERJ.
Researchers conducted two replicate, double-blind studies over 6 weeks to assess the effects of tiotropium/olodaterol, compared with monotherapy and placebo, on inspiratory capacity and exercise endurance times in 571 patients with moderate to severe COPD.
Each patient was administered treatment once a day for 6 weeks, with a 21-day washout period between treatments. Primary outcomes were inspiratory capacity prior to exercise and exercise endurance time during constant work-rate cycle after 6 weeks.
The results showed that once-daily tiotropium/olodaterol therapy led to improvements in lung hyperinflation compared with placebo monotherapy patients. There was also evidence of improvements in dyspnoea and exercise tolerance versus the placebo, but this improvement was not consistent with monotherapy.
The evidence suggests that dual treatment leads to better lung deflation, but this does not consistently improve exercise tolerance, as endurance times in COPD patients were not significantly increased following simultaneous tiotropium/olodaterol therapy.
Limitations to the research include the possibility that severe COPD patients in need of effective lung deflation may be underrepresented in this study, in addition to the prevalence of muscle deconditioning among COPD patients that can also hinder physical capacity.