Patient description: The patient is a 63-year-old man presenting to the Emergency Department with a history of acute urinary retention in the past 2 days. Abdominopelvic CT scan revealed a large prostate and a bladder filled with urine. He is a candidate for urethral catheterization and TURP. Further evaluation revealed: Post-void residual: 71 mL Prostate volume (TRUS): 63 mL Prostate-specific antigen (PSA) level: 3.5 ng/mL His recent blood chemistry (3 days ago) was normal: Hgb: 13.6 g/dl WBC: 133000 /mm3 Plt: 370000 /ml PT: 12 second PTT: 34 second INR: 0.9 Creatinine: 0.5 mg/dl BUN: 10 mg/dl U/A: Color: yellow Appearance: cloudy PH: 5.3 Specific gravity: 1.010 Glc: 100 Nitrite: negative Ketone: none Leukocyte esterase: negative RBC: negative WBC: 2 WBCs/hpf U/C: negative

Clinical trial eligibility criteria: eligible ages (years): 40.0-99.0,  Bladder Outlet Obstruction Patients will be selected by the investigator and sub-investigator's patient population, and physician referrals. All patients will meet the inclusion/   1. Male ≥40 years of age 2. Clinical signs and symptoms of frequency and urgency, enlarged prostate and urodynamic study consistent with overactive bladder. 3. IPSS >12, with IPSS QoL > 3 at screening visit. 4. Ability and willingness to correctly complete the micturition diary and all the trial related questionnaires comply with scheduled visits and comply with trial procedures. 5. Capability of understanding and having signed the informed consent form after full discussion of the research, nature of the treatment, and its risks and benefits. 6. Procedure to treat BOO by TURP or PVP greater than or equal to 1 month ago A known history of interstitial cystitis, uninvestigated hematuria, or bladder outlet obstruction due to: mullerian duct cysts, urethral obstruction due to stricture/valves/sclerosis of urethral tumor, radiation cystitis, genitourinary tuberculosis, bladder calculi, or detrusor-sphincter dyssynergia. 2. Evidence of Urinary Tract Infection according to local standard of care. 3. Expectation of initiating treatment during the duration of this study with any drug treatment for OAB, any drugs with significant anticholinergic, antispasmodic, parasympathetic, or cholinergic agonistic effects. 4. Use of any electrostimulation within the 30 days before randomization, or the expectation to initiate such therapy during the study. 5. Any condition which, in the opinion of the investigator, makes the patient unstable, or with contraindications for e.g., uncontrolled narrow-angled glaucoma, urinary retention, preplanned prostate surgery, or gastric retention. 6. Significant hepatic or renal disease, defined as twice the upper limit of the reference ranges regarding serum concentrations of AST, ALT, ALP, urea nitrogen, or creatinine. 7. Use of any other investigational drug in the 2 months preceding visit 1. 8. History of postural hypotension or syncope in the judgement of the investigator based on local standards of care. 9. Alcohol and/or any other drug abuse in the opinion of the investigator. 10. Medications such as erythromycin, Biaxin (Clarithromycin), Sporanox (itraconazole), Nizoral (ketoconazole), Neoral and Sandimmune (cyclosporine), Velban (vinblastine) and miconazole. 11. Non-medication treatments such as bio-feedback or other bladder training exercises