Co-administration of Olodaterol Respimat® and Tiotropium Handihaler®

Inclusion criteria: 1. All patients must sign an informed consent consistent with International Conference on Harmonization-Good Clinical Practice (ICH-GCP) guidelines prior to participation in the trial, which includes medication washout and restrictions. 2. All patients must have a diagnosis of chronic obstructive pulmonary disease and must meet the following spirometric criteria: Patients must have a relatively stable airway obstruction with a post-bronchodilator FEV1 ≥ 30 % and \< 80% of predicted normal and a post-bronchodilator FEV1/FVC \<70% at Visit 1. 3. Male or female patients, 40 years of age or older. 4. Patients must be current or ex-smokers with a smoking history of more than 10 pack years 5. Patients must be able to: perform technically acceptable pulmonary function tests, and maintain records(paper diary). 6. Patients must be able to inhale medication in a competent manner from the Respimat Inhaler as well as the Handihaler. Exclusion criteria: 1. Patients with a significant disease other than COPD; a significant disease is defined as a disease which, in the opinion of the investigator, may (i) put the patient at risk because of participation in the study, (ii) influence the results of the study, or (iii) cause concern regarding the patients ability to participate in the study. 2. Patients with clinically relevant abnormal baseline haematology, blood chemistry, or urinalysis; all patients with an AST \>x2 ULN, ALT \>x2 ULN, bilirubin \>x2 ULN or creatinine \>x2 ULN will be excluded regardless of clinical condition (a repeat laboratory evaluation will not be conducted in these patients). 3. Patients with a history of asthma. For patients with allergic rhinitis or atopy, source documentation is required to verify that the patient does not have asthma. If a patient has a total blood eosinophil count ≥600/mm3, source documentation is required to verify that the increased eosinophil count is related to a non-asthmatic condition. 4. A diagnosis of thyrotoxicosis (due to the known class side effect profile of ß2-agonists). 5. A diagnosis of paroxysmal tachycardia (\>100 beats per minute) (due to the known class side effect profile of ß2-agonists). 6. A history of myocardial infarction within 1 year of screening visit (Visit 1). 7. Unstable or life-threatening cardiac arrhythmia. 8. Hospitalization for heart failure within the past year. 9. Known active tuberculosis. 10. A malignancy for which patient has undergone resection, radiation therapy or chemotherapy within last five years (patients with treated basal cell carcinoma are allowed). 11. A history of life-threatening pulmonary obstruction. 12. A history of cystic fibrosis. 13. Clinically evident bronchiectasis. 14. A history of significant alcohol or drug abuse. 15. Patients who have undergone thoracotomy with pulmonary resection (patients with a history of thoracotomy for other reasons should be evaluated as per exclusion criterion No. 1). 16. Patients being treated with oral or patch ß-adrenergics. 17. Patients being treated with oral corticosteroid medication at unstable doses (i.e., less than six weeks on a stable dose) or at doses in excess of the equivalent of 10 mg of prednisone per day or 20 mg every other day. 18. Patients who regularly use daytime oxygen therapy for more than one hour per day and in the investigators opinion will be unable to abstain from the use of oxygen therapy during clinic visits. 19. Patients who have completed a pulmonary rehabilitation program in the six weeks prior to the screening visit (Visit 1) or patients who are currently in a pulmonary rehabilitation program. 20. Patients who have taken an investigational drug within one month or six half lives (whichever is greater) prior to screening visit (Visit 1). 21. Patients with known hypersensitivity to ß-adrenergic drugs, BAC, EDTA, or any other component of the Respimat® inhalation solution. 22. Patients with known hypersensitivity to anticholinergic drugs, lactose, or any other components of the HandiHaler®. 23. Pregnant or nursing women. 24. Women of childbearing potential not using a highly effective method of birth control\*. Female patients will be considered to be of childbearing potential unless surgically sterilised by hysterectomy or bilateral tubal ligation, or post-menopausal for at least two years. \* as per ICH M3(R2) a highly effective method of birth control is defined as those which result in a low failure rate (i.e. less than 1% per year). 25. Patients who have previously been randomised in this study or are currently participating in another study. 26. Patients who are unable to comply with pulmonary medication restrictions prior to randomisation.