Detrusor Overactivity May Be a Prognostic Factor for Better Response to Combination Therapy Over Monotherapy in Male Patients With Benign Prostatic Enlargement and Storage Lower Urinary Tract Symptoms

PURPOSE: Several trials have shown that in men with overactive bladder (OAB) and benign prostate enlargement (BPE), the combination of an α-blocker with an anticholinergic is superior to α-blocker monotherapy. The purpose of this study is to explore whether urodynamic detrusor overactivity (DO) affects clinical outcomes in men with BPE and OAB. METHODS: This is a post hoc analysis of a prospective, randomized trial, designed to evaluate the changes of morphometric parameters of the prostate following monotherapy or combination therapy in men with BPE-OAB. The initial study recruited men aged ≥50 years, with BPE and predominantly storage lower urinary tract symptoms (LUTS). Patients were randomized to receive tamsulosin monotherapy or a combination of tamsulosin and solifenacin for 26 weeks. All participants completed a 3-day bladder diary and the International Prostate Symptom Score (IPSS), and then underwent pressure-flow and ultrasonographic studies. Data were stratified and analysed based on the urodynamic observation of DO at baseline (DO vs. non-DO). The primary endpoint was the mean change in urgency episodes from baseline. Secondary outcomes were the changes in nocturia, total IPSS, and urodynamic parameters. RESULTS: Sixty-nine men were initially randomized, but only 60 men were included in this analysis. Urgency episodes significantly improved in men with DO who received combination therapy compared to the DO monotherapy subgroup (P=0.04) or to the non-DO combination treatment subgroup (P=0.038). Nocturia also improved in the DO combination treatment subgroup as compared to the non-DO combination subgroup (P=0.037). The 24-hour frequency and total IPSS significantly improved from baseline without significant differences among the subgroups. CONCLUSIONS: The present study suggests that baseline DO could be a prognostic factor for a better response to combination therapy over monotherapy in men with BPE and storage LUTS.