Comparison of Combination Therapy vs Single Agent Therapy for Treatment of Urge Incontinence.

Double-Blind Randomized Controlled Trial of Extended Release Oxybutynin Versus Placebo in Women Receiving Posterior Tibial Nerve Stimulation for Treatment of Urgency Urinary Incontinence

This is a randomized double-blind placebo-controlled clinical trial of posterior tibial nerve stimulation (PTNS) plus extended release oxybutynin versus PTNS alone (placebo pills) in women undergoing treatment of urgency urinary incontinence (UUI).

The investigators hypothesize that combination therapy with PTNS and anticholinergic medication will result in a significant incremental improvement in UUI symptoms over that achieved with PTNS alone. In addition, the investigators hypothesize that the addition of anticholinergics to PTNS will result in a greater improvement in patients' perception of treatment response, symptom distress, and quality of life than PTNS alone.

Specific Aim 1: To compare the change, from baseline, in mean number of UUI episodes per day using a 3-day bladder diary between PTNS plus anticholinergic medication versus PTNS plus placebo in women undergoing treatment for UUI.

Specific Aim 2: To compare the change, from baseline, in a 24hr pad weight between PTNS plus anticholinergic medication versus PTNS plus placebo.

Specific Aim 3: To compare subjective treatment response, symptoms distress, and quality of life between PTNS plus anticholinergic medication versus PTNS plus placebo utilizing the Patient Global Impression of Improvement (PGI-I) and the Overactive Bladder Questionnaire Short Form (OABq-SF).

An interim analysis will be conducted by an independent entity after 50 participants have completed the study protocol. A Data Safety Monitoring Board is not utilized because the study utilizes FDA approved treatments for urgency urinary incontinence.

Inclusion Criteria:

• Female patients
• > 18 years of age
• > 3 UUI episodes on a 3-day bladder diary
• Urge predominant ( > 50% of total incontinence episodes) urinary incontinence based on a three-day bladder diary
• Existing insurance coverage of PTNS therapy.
• Ability to undergo weekly PTNS treatments in clinic for 6 week period of time and complete all study related items
• Not on an anticholinergic or beta agonist medication or, if they are, willing to undergone a three week washout period prior to randomization

Exclusion Criteria:

• Any previous PTNS therapy, intra-detrusor botulinum toxin injections, or implanted sacral neuromodulation
• Contraindication to anticholinergic therapy (narrow-angle glaucoma or gastric retention) or PTNS therapy (implanted pacemaker/defibrillator or peripheral neuropathy)
• Symptomatic urinary tract infection that has not resolved prior to randomization
• Surgical treatment for stress urinary incontinence or pelvic organ prolapse recommended or planned at time of enrollment
• Surgically altered detrusor muscle
• Known diagnosis or history of neurogenic bladder, post void residual volume >150ml, bladder malignancy, interstitial cystitis/painful bladder syndrome, or pelvic radiation
• Surgery for pelvic organ prolapse or stress urinary incontinence within the previous 3 months
• Pregnancy, lactation, or planned pregnancy during study period