This study investigated what sort of effects would occur in terms of sexual function in Japanese patients with benign prostatic hyperplasia (BPH), upon switching from combination therapy with an α1 blocker (AB) and dutasteride (DUT) to combination therapy with tadalafil (TAD) and DUT. The baseline and the 15-item International Index of Erectile Function (IIEF-15), Erection Hardness Score (EHS), International Prostate Symptom Score (IPSS), and Overactive Bladder Symptom Score (OABSS) 3 months after switching to the daily administration of TAD 5 mg/DUT 0.5 mg combination therapy, along with the age, prostatic volume, body mass index (BMI), and past medical history of 49 patients who were treated with AB/DUT as pretreatment, were retrospectively investigated. TAD/DUT combination therapy significantly improved the total score of IIEF-15 (from 17.8 ± 11.6 to 21.4 ± 13.9, p = .0047), erectile function domain (from 5.8 ± 5.8 to 7.6 ± 7.1, p = .0186), and EHS (from 1.9 ± 1.3 to 2.6 ± 1.2, p < .0001). Although IPSS and QOL index were significantly improved, no significant differences were observed for OABSS. Switching from AB/DUT combination therapy to TAD/DUT combination therapy brought about improvement in erectile function while leaving room to improve urinary status in Japanese patients.
Keywords: Erection Hardness Score; International Index of Erectile Function; combination therapy; dutasteride; erectile dysfunction; tadalafil.