Five RCTs reported in 11 publications were included in the review (n=2119 patients in table, 2054 patients in figure). All trials were double blinded. The proportion of withdrawals ranged from 3 to 16%. Four trials scored 3 on the Jadad scale and one scored 4. Duration of follow-up ranged from eight to 12 weeks.
Compared with placebo, phosphodiesterase-5 inhibitors were associated with a significant reduction in the overall International Prostate Symptom Score (IPSS) (WMD-2.6%, 95% CI -3.12 to -2.07; five RCTs), IPSS irritative subscore (WMD -0.96%, 95% CI -1.22 to -0.71; four RCTs), IPSS obstructive subscore (WMD -1.57%, 95% CI -1.92 to -1.21; four RCTs), the IPSS quality of life subscore (WMD -0.39%, 95% CI -0.52 to -0.27; three RCTs) and the IIEF-EF (WMD 5.74%, 95% CI 4.78 to 6.70; four RCTs). There was no significant difference between phosphodiesterase-5 inhibitors and placebo for post-void residual urine volume or maximal urinary flow rate. There was no evidence of heterogeneity for any of these analyses. Subgroup analyses showed similar results.
Phosphodiesterase-5 inhibitors were associated with significantly more adverse events that placebo (RR 1.87, 95% CI 1.31 to 2.68; five RCTs). There was substantial heterogeneity for this outcome (I2=80%). The most commonly reported adverse events were headache, flushing, dyspepsia, and back pain. There was no significant difference between interventions for serious adverse events.