The overall objective is to asses the bronchodilator effect of Tiotropium/Salmeterol/Fluticasone combination delivered via Discair® twice daily as compared with original products Seretide Diskus 500 mcg Inhalation Powder twice daily and Spiriva 18 mcg Inhalation Powder once daily free combination treatment in patients with stable moderate to severe COPD.
For formerly diagnosed patients who met all the inclusion criteria and receiving COPD treatment, the day of the screening visit will be based on the completion of a run-in period, with the length determined by the specific medication. During the run-in period, salbutamol (100 μg inhaler) will be prescribed as a rescue medication.
Patients (following run-in period for formerly diagnosed patients) will be randomly assigned to receive Tiotropium/Salmeterol/Fluticasone fixed dose combination as dry powder inhalation delivered via Discair® twice daily or Seretide Diskus 500 mcg Inhalation Powder twice daily and Spiriva 18 mcg Inhalation Powder once daily free combination for 2-days treatment period.
Patients will be evaluated at 4 consecutive visits: baseline (enrollment), screening, treatment and after treatment.
Spirometric measurements will be performed totally at 15 different time points at pretreatment and post-treatment (pre-dose, 15. min, 30. min, 1. hr, 2. hr, 4.hr, 8.hr and 12.hr) during the first treatment day and at 16 different time points (15. min, 30. min, 1. hr, 2. hr, 4.hr, 6 hr, 8.hr and 12.hr) during the second treatment day.
