Tiotropium 5microg via Respimat and 18microg via HandiHaler; efficacy and safety in Japanese COPD patients.

BACKGROUND AND OBJECTIVES

To compare the efficacy and safety of tiotropium inhaled via Respimat Soft Mist Inhaler, a multidose propellant-free inhaler and HandiHaler, a single-dose dry powder inhaler, in a phase 2 study of Japanese COPD patients.

METHODS

Patients with FEV(1)<or=70% predicted, FEV(1)/FVC<or=70% and a smoking history of >10 pack-years received tiotropium once daily via Respimat (5microg) and HandiHaler (18microg) for 4 weeks each in a randomised, double-blind, double-dummy, two-way crossover study. Lung function, adverse events, pharmacokinetics and safety were assessed.

RESULTS

Of 184 patients screened, 134 were evaluable. The trough FEV(1) response on Day 29 showed Respimat to be non-inferior to HandiHaler (mean treatment difference, 0.008L; 95% CI, -0.009 to +0.024L; p<0.001). Peak and average FEV(1) and FVC responses on Day 1 and Day 29 were very similar for the two treatments. Tiotropium plasma levels and excretion kinetics showed a similar profile of systemic exposure for the two formulations of tiotropium. Adverse events were reported by similar numbers of patients on each treatment, i.e. 27.9 and 30.6% in the Respimat and HandiHaler groups, respectively.

CONCLUSIONS

In Japanese patients with COPD, tiotropium Respimat 5microg and tiotropium HandiHaler 18microg showed a similar profile of efficacy, safety and pharmacokinetics.