Trial Comparing Treatment With Tiotropium Inhalation Capsules to Combivent® Inhalation Aerosol in COPD Patients.

Inclusion Criteria: * Diagnosis of COPD * Age: \>= 40 years * Current or ex-smoker with a \>= 10 pack-year smoking history * Use of Combivent® MDI for \>= 1 month prior to Visit 1 Spirometric criteria (determined at study visits): * Post-bronchodilator FEV1 \<= 70% (Visit 1) * Pre-bronchodilator FEV1 \<= 65% of predicted and FEV1/FVC \<= 70% (Visit 2) Exclusion Criteria: * Clinical history of asthma * History of thoracotomy with pulmonary resection * History of CF, alpha 1 antitrypsin deficiency or interstitial lung disease * Daytime use of oxygen therapy for \> 1 hour per day or if unable to abstain from using oxygen during PFTs * Any respiratory tract infection or COPD exacerbation in 6 weeks prior to Visit 1 * Recent history 6 months or less of MI * Unstable or life-threatening cardiac arrhythmias * Hospitalization for CHF during past year * Malignancy for which patient is receiving chemo or radiation therapy * Pregnant or nursing women * Known hypersensitivity to ipratropium or carrier substances, including related food products such as soybean, peanuts, or lactose * Use of SPIRIVA® 3 months prior to Visit 1 * Symptomatic of prostatic hypertrophy or bladder neck obstruction * Known narrow- angle glaucoma * Participating in a pulmonary rehab program within 4 weeks of Visit 1