Combination therapy with dutasteride and tadalafil in men with moderate-to-severe benign prostatic hyperplasia

INTRODUCTION & OBJECTIVES: Benign prostatic hyperplasia (BPH) is commonly treated with alpha-blockers and 5alpha-reductase inhibitors (5ARIs). However, 5ARIs have sexual side effects, including erectile dysfunction (ED). Recently tadalafil 5mg administrated once daily is known to be helpful for LUTS. So, we investigated the efficacy of combination of tadalafil and dutasteride compared with combination of tamsulosin and dutasteride in improving symptoms in men with moderate-to-severe symptoms of BPH. MATERIAL & METHODS: This 12 week study was a randomized, parallel group study of clinical outcomes in men aged ≥ 50 years with symptomatic (IPSS≥ 12) BPH, with a prostate volume of ≥ 30 mL. Eligible patients received a combination of tadalafil 5mg with dutasteride 0.5mg (n=86), or a combination of tamsulosin 0.2mg with dutasteride 0.5mg (n=82). The primary outcome included posttreatment analysis of IPSS, peak urinary flow rate, post void residual urine volume(PVR). Secondary outcome were change in the score of IIEF-EF domain, Global Assessment Question (GAQ), and the Life Satisfaction Checklist (LSC). RESULTS: There is no difference between IPSS improvement from baseline through 12 wk in both group (tadalafil+dutasteride; -2.3 vs. tamsulosin+dutasteride; -2.5; p=0.634). Also, the change of Q(max) and PVR from baseline in both group did not show significant difference. However, tadalafil+dutasteride group showed significantly greater change in the IIEF-EF domain score from baseline compared with the tamsulosin+dutasteride (3.3 vs. -0.8, P<0.0001). As for the GAQ and LSC scores, the tadalafil+dutasteride group showed signficantly greater improvements. Adverse event profiles were consistent with previous reports. CONCLUSIONS: Combination therapy of tadalafil and dutasteride resulted in similar improvements versus combination of tamsulosin and dutasteride in LUTS/BPH. However, combination of tadalafil and dutasteride have a obvious benefit in erectile function. Tadalafil can compensate for the decreased erectile function by dutasteride and improve LUTS.