This study will evaluate the pharmacologic effects of exposure to darifenacin and tolterodine on cardiovascular parameters in healthy subjects 50 years of age and older

Inclusion Criteria:

• Healthy males and females ≥ 50 years
• Body mass index equal to or greater than 18.5 kg/m2 and less than 35.0 kg/m2

Exclusion Criteria:

• Known or suspected allergy to tolterodine ER or darifenacin or their components
• Subjects with irregular day and night patterns such as night shift workers
• Significant medical problems know to affect heart rate (ie., hypertension, hypotension, history of heart failure, history of pulmonary disease, etc.)
• Medication with potential known to affect heart rate
• History of any malignancy within the past 5 years, with the exception of localized basal cell carcinoma of the skin
• Pregnant or nursing women
• Subjects with diseases such as urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, severe renal insufficiency, etc.

Other protocol-defined inclusion/exclusion criteria may apply