Efficacy of Tadalafil for treating chronic prostatitis/chronic pelvic pain syndrome in patients without erectile dysfunction

INTRODUCTION AND OBJECTIVES: PDE5 inhibitors increase blood flow to the pelvic organs and improve lower urinary tract symptoms, so it is postulated that PDE5 inhibitors could be effective on treating chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). In this background, we investigated the efficacy of tadalafil for the treatment of CP/CPPS in patients without erectile dysfunction (ED). METHODS: Eighty-six males with a National Institutes of Health (NIH) diagnosis of category III CP/CPPS, but who did not have ED, were randomized in single-blinded fashion to receive either levofloxacin (500 mg/day; group 1; 40 patients) or levofloxacin (500 mg/day) and tadalafil (5 mg/day; group 2; 46 patients) for 6 weeks. The International Prostate Symptom Score (IPSS), NIH chronic prostatitis symptom index (NIH-CPSI), and erectile function (EF) domain scores of the International Index of Erectile Dysfunction (IIEF) questionnaire were used to grade symptoms at baseline and 6 weeks later. RESULTS: The mean ages of the two groups were 49.2±6.7 and 48.3±7.1 years, respectively. There were no significant differences between the groups in age, duration of the condition, IPSSs, NIH-CPSI scores, or IIEF-EF domain scores at baseline. Tadalafil significantly improved the mean change in the IPPS from baseline to 6 weeks (group 1; -1.1 vs. group 2; -4.2, p<0.05). Significant improvements were also evident in the IPSS voiding subscore (group 1; -0.7 vs. group 2; -3.1, p<0.05). Larger changes from the NIH-CPSI baseline score were evident at 6 weeks in group 2 (group 1; -3.1 vs. group 2; -7.3, p<0.05). Significant improvements were also apparent in the NIH-CPSI voiding domain scores (group 1; -0.5 vs. group 2; -1.8, p<0.05) and the QoL domain scores (group 1;-1.0 vs. group 2;-1.9, p<0.05). Group 2 exhibited a greater increase in the IIEF-EF score; this was significant (group 1; +0.2 vs. group 2; +3.8, p<0.05). Commonly reported (one case or greater) treatment-related adverse events in group 2 were frequent erections, dyspepsia, and headache (two or fewer cases of each); however, no patients discontinued treatment due to adverse events. CONCLUSIONS: Tadalafil 5 mg daily was well-tolerated and afforded significant symptomatic improvements in non-ED patients with CP/CPPS.