Effects of a single dose 20 mg tadalafil on resistive index value of prostate zones

Abstract

Objectives: Although there are several studies addressing the efficacy of phosphodiesterase type 5 inhibitorsfor the management of benign prostatic hyperplasia-lower urinary tract symptoms (BPH-LUTS), unfortunately,there is a lack of high evidence data to support their effect at the prostate level. The existing studies suggestedthat resistive index (RI) could be used as a hemodynamic parameter to measure the severity of benign prostatichyperplasia and intraprostatic pressure or bladder outlet obstruction. The aim of this study was to evaluate theeffect of a single dose 20 mg tadalafil on resistive index value in prostate zones to evaluate the mechanism ofaction of phosphodiesterase type 5-inhibitors at the prostate level.Methods: Twenty consecutive patients aged between 54-67 years with BPH-LUTS [International ProstateSymptom Score ≥ 12] and erectile dysfunction [five-item International Index of Erectile Function (IIEF)questionnaire < 22] underwent RI measurement in prostate transitional zone (TZ) and peripheral zone (PZ)using transrectal power Doppler ultrasonography baseline and within 16 hours after the administration of 20mg tadalafil. The primary study end point is the change in prostate TZ RI values.Results: The mean baseline total prostate scores and peak urinary flow were 16.2 ± 4.34 (range: 12-26) and10.45 ml/s (range: 7-13 ml/s), respectively. The mean baseline total IIEF was 12.8 ± 4.22 (range: 6-20). Themean TZ RI at baseline and after tadalafil administration were 0.4985 and 0.5497, respectively (p = 0.232).No statistically significant differences for RI changes between baseline and after the administration of a singledose 20 mg tadalafil were observed in the prostatic zones.Conclusion: A single dose 20 mg tadalafil showed no impact on prostate TZ RI.