The Efficacy of Solifenacin With or Without Tamsulosin in Adult Women With Overactive Bladder (OAB)

Inclusion Criteria: * Female aged 20 ≤ and \< 70 years * History of OAB symptoms for ≥ 3 months * International Prostate Symptom Score (IPSS) ≥ 8 points at Screening and more than 3 in total score and 2 in Q 3 index from OABSS questionnaire * An average of ≥ 8 micturitions per 24 hours and ≥ 1 urgency (defined as a level of 3 to 5 in a 5 point Urinary Sensation Scale) episode (with or without incontinence) per 24 hours as documented in a 3-day micturition diary Exclusion Criteria: * Uroflowmetry - Q max ≤ 10 mL/sec, or Post Void Residual Volume ≥ 15% of voided urine * Any condition that would contraindicate their usage of anticholinergics or alpha blockers * History of lower urinary tract surgery (e.g. incontinence surgery or electrostimulation) * History of stress urinary incontinence or urinary retention * History of interstitial cystitis, bladder outlet obstruction or other significant genitourinary disorder * Pregnant or nursing women * Current urinary tract infection * Neurological bladder dysfunction * Treatment with drugs that may interfere with CYP3A4 metabolic function * Significant hepatic or renal disease * Any other condition which, in the opinion of the investigator, makes the patient unsuitable for inclusion