The objective of this study is to confirm that chronic dosing of 20 mcg and 40 mcg of ipratropium bromide, administered via the RESPIMAT device, demonstrates clinical comparability and similar safety profiles to the 36 mcg dose of ATROVENT® Inhalation Aerosol (containing chlorinated fluorocarbons (CFC)) in patients with chronic obstructive pulmonary disease (COPD). The efficacy and safety profiles of the two doses administered via the RESPIMAT device will also be compared to their respective placebo groups

Inclusion Criteria:

1. All patients must have a diagnosis of COPD and must meet the following spirometric criteria:

   • Patients must have relatively stable, moderate to severe airway obstruction with a FEV1 =< 65% of predicted normal and FEV1 =< 70% of FVC

2. Male or female patients 40 years of age or older

3. Patients must have a smoking history of more than ten packs-years. A pack-year is defined as the equivalent of smoking one pack of 20 cigarettes per day for a year

4. Patients must be able to perform pulmonary function tests and maintain records during the study period, as required in the protocol

5. Patients must be able to be trained in the proper use of an inhalation aerosol and the Respimat device

6. All patients must sign an Informed Consent Form prior to participation in the trial i.e., at least 24 hours prior to screening (Visit 1)

Exclusion Criteria:

1. Patients with significant diseases other than COPD will be excluded. A significant disease is defined as a disease, which in the opinion of the investigator, may either put the patient at risk because of participation in the study or a disease which may influence the results of the study or the patient's ability to participate in the study
2. Patients with clinically relevant abnormal baseline haematology, blood chemistry or urinalysis. If the abnormality defines a disease listed as an exclusion criterion, the patient is excluded
3. All patients with a serum glutamate oxaloacetate transaminase > 80 U/L, serum glutamate pyruvate transaminase > 80 U/L, bilirubin > 34.2 µmol/L or creatinine > 176.8 µmol/L will be excluded regardless of the clinical condition. Repeat laboratory evaluation will not be conducted in these subjects
4. Patients who have a blood eosinophil count >= 0.6 GI/L. A repeat eosinophil count will not be conducted in these patients
5. Patients with a recent history (i.e., one year or less) of myocardial infarction
6. Patients with a recent history (i.e., three years or less) of heart failure or patients with any cardiac arrhythmia requiring drug therapy
7. Patients with a history of cancer, other than treated basal cell carcinoma, within the last five years
8. Patients with a history of life-threatening pulmonary obstruction, or a history of cystic fibrosis or bronchiectasis
9. Patients who have undergone thoracotomy with pulmonary resection. Patients with a history of a thoracotomy for other reasons should be evaluated as per exclusion criterion #1
10. Patients with a history of asthma, allergic rhinitis or atopy
11. Patients with a history of and/or active alcohol or drug abuse
12. Patients with known active tuberculosis
13. Patients with an upper respiratory tract infection or COPD exacerbation in the past six weeks prior to the Screening Visit (Visit 1) or during the baseline period
14. Patients with known symptomatic prostatic hypertrophy, bladder neck obstruction, or urinary retention
15. Patients with known narrow-angle glaucoma, or raised intra-ocular pressure
16. Patients with current significant psychiatric disorders
17. Patients with regular use of daytime oxygen therapy
18. Patients who are being treated with cromolyn sodium or nedocromil sodium
19. Patients who are being treated with antihistamines
20. Patients using oral corticosteroid medication at unstable doses (i.e., less than six weeks on a stable dose) or at a dose in excess of the equivalent of 10 mg of prednisone per day or 20 mg every other day
21. Patients who are being treated with beta-blocker medication
22. Patients who have had changes in their therapeutic plan within the last six weeks prior to the Screening Visit (Visit 1)
23. Pregnant or nursing women or women of childbearing potential not using a medically approved means of contraception (i.e., oral contraceptives, intrauterine devices or diaphragm with spermicide, or Norplant®)
24. Patients with known hypersensitivity to anticholinergic drugs or any other components of the ATROVENT® Solution including Benzalkonium chloride and Edetic acid
25. Patients who have taken an investigational drug within one month or six half lives (whichever is greater) prior to Screening Visit (Visit 1)
26. Previous participation in this study