Effect of tadalafil once daily on prostate blood flow and perfusion in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia: a randomized, double-blind, multicenter, placebo-controlled trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 24938580 · doi:10.1016/j.urology.2014.02.063
What was done
Men aged ≥45 years with moderate-to-severe lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH-LUTS) were randomized to receive once-daily tadalafil 5 mg (n = 47) or placebo (n = 50) for 8 weeks. Prostatic blood flow was measured via transrectal ultrasonography at baseline, week 4, and week 8. The primary outcome was the change in prostate transition zone (TZ) resistive index (RI). Secondary outcomes included RI in the peripheral zone and bladder neck, as well as color pixel intensity (CPI) and color pixel density (CPD) in all three regions, analyzed via mixed-model repeated-measures.
What was found
Tadalafil did not produce statistically significant changes in prostatic blood flow compared with placebo. The least squares mean change in prostate TZ RI from baseline to week 8 was -0.01 for placebo versus 0.00 for tadalafil (P = .118). Changes in TZ CPI (P = .564) and TZ CPD (P = .592) were also non-significant, with similar null findings across the peripheral zone and bladder neck.
Why it matters
Although daily PDE5 inhibitors improve urinary symptoms in BPH, this trial shows that the therapeutic benefit is not explained by macroscopic improvements in prostate or bladder neck blood perfusion detectable by transrectal Doppler ultrasound.
Limits
The sample size was modest (n = 97) and follow-up was limited to 8 weeks. Transrectal Doppler ultrasonography may lack the sensitivity to detect subtle microvascular perfusion changes, baseline arterial resistance was already low, and multicenter imaging variation may have introduced measurement noise.
Cited by
- contradicts Low-dose tadalafil (2.5 to 5 mg per day) is effective for improving perfusion of the prostate.