The purpose of this study is to compare the efficacy of DITROPAN® XL (oxybutynin chloride) Extended-Release Tablets and DETROL® LA (tolterodine tartrate extended-release capsules) in the reduction of urge urinary incontinence episodes during a 12-week treatment period in patients with overactive bladder. The secondary objective is to compare the tolerability of DITROPAN® XL (oxybutynin chloride) and DETROL® LA (tolterodine tartrate) during a 12-week treatment period.

The objective of this study is to compare the efficacy and tolerability of DITROPAN® XL 10 mg once-daily and DETROL® LA 4 mg once-daily in the reduction of urge urinary incontinence episodes in female patients with overactive bladder. This is a multicenter, randomized, double-blind, parallel-group study with two active treatments. Screened patients are qualified for the study based on information obtained from seven consecutive 24-hour urinary diaries completed during the Baseline Week, and other eligibility criteria. Qualifying patients receive 12 weeks of treatment with DITROPAN® XL or DETROL® LA, with clinical visits at the end of Weeks 2, 4, 8, and 12.

Safety evaluations during the study include the collection of adverse events, laboratory tests including blood chemistry and urinalysis, physical examinations, vital signs (blood pressure and heart rate) and post-void residual urine volume. Over-encapsulated DITROPAN® XL, 10 mg tablets once-daily by mouth or over-encapsulated DETROL® LA, 4 mg capsules once daily by mouth. The treatment phase of the study runs for 12 weeks.

Inclusion Criteria:

• Participants who are able to differentiate urinary incontinence episodes associated with urgency from urinary incontinence episodes not associated with urgency
• during the 7 day baseline period have 21 to 60 urge urinary incontinence (Urge-UI) episodes, a greater number of Urge-UI episodes than urinary incontinence not associated with urge, and an average of 10 or more voids per 24 hours
• are in good general health as determined by medical history, physical examination (general, genital, pelvic, and rectal), laboratory tests and urinalysis
• if taking antihypertension medication, must be on a stable dose
• and if of child-bearing potential, practicing an acceptable method of birth control, and must have a negative pregnancy test at Visit 2 and Visit 3

Exclusion Criteria:

• Participants with known, treatable genitourinary conditions (identified on history or on examination) that may cause incontinence (e.g., urinary tract infection, interstitial cystitis, urinary tract obstruction, urethral diverticulum, bladder tumor, bladder stone)
• have given birth or have had pelvic, vaginal or bladder surgery less than 6 months before study enrollment
• with a second post-void residual urine volume > 150 mL at the time of screening (determined by abdominal ultrasound)
• with significant medical problems or other organ abnormality that places them at risk from participating in the study or at a significant risk of developing complete urinary retention
• with significant impairment of the liver or kidneys as determined by laboratory assessments or hematuria (red blood cells in microscopic urinalysis)