An Efficacy and Safety Evaluation of Tiotropium add-on Therapy in Patients With Severe Persistent Asthma

Inclusion Criteria: Outpatients of either sex, age 18 - 75 years, with at least a documented 5 year history of asthma, and a current diagnosis of severe, persistent asthma (GINA step 4), smoking history \< 10 pack years and \>= 1 year smoking cessation; Patients must be symptomatic Exclusion Criteria: Patients * with a recent history (i.e., six months or less) of myocardial infarction, * who have been hospitalized for heart failure (NYHA class III or IV) within the past year, * with any unstable or life threatening cardiac arrhythmia or cardiac arrhythmia requiring intervention or a change in drug therapy within the past year, * with malignancy for which the patient has undergone resection, radiation ther apy or chemotherapy within the last five years, * who have undergone thoracotomy with pulmonary resection, * with moderate to severe renal impairment (creatinine clearance = 50 mL/min)