5-alpha reductase inhibitors (5ARIs) are often used for the treatment of BPH, however there is limited evidence on their efficacy after a transurethral prostatectomy (TURP); despite this they are commonly used post-TURP, as we have shown with our previous research. Our objective was to determine if 5ARI use after an episode of gross hematuria following a TURP reduces the risk of further episodes of gross hematuria.

We conducted a population based retrospective cohort study using data from Ontario, Canada. Men who had a TURP between 2003-2016 were included and we excluded those with a prior TURP, prostate cancer, a bladder tumor resection, or <66yrs. We identified men who returned to the hospital/ER with gross hematuria at least 90 days after their TURP, and used the date of the initial episode of gross hematuria as the study start date. We treated the use of 5ARIs as our primary time-varying exposure. The primary outcome was recurrent hospital/emergency room visits with gross hematuria. We used an Anderson-Gill proportional hazards model to evaluate the association between 5ARI utilization and gross hematuria.

There were 9,449 men who had at least one episode of gross hematuria post-TURP. The median age was 80 (IQR 75-85), and most underwent an electrosurgical TURP. The median time between the TURP and the initial episode of gross hematuria was 3 years. During the study period, there were 2,713 (29%) men who had at least one prescription for 5ARIs. Our primary analysis showed that 5ARI users actually had an increased rate of emergency room visits or hospital admissions for gross hematuria compared to non-5ARI users (adjusted HR 1.22, 95% CI 1.05-1.43). However, this was no longer statistically significant in a number of sensitivity analyses (with hazard ratios closer to 1).

We did not find that 5ARI use among men with an episode of gross hematuria post TURP reduced the rate of repeat episodes of gross hematuria requiring medical attention compared to non-5ARI users.  The use of 5ARIs after TURP is common, however the efficiacy is generally not proven. A single RCT did not show any benefit to 5ARIs in terms of reducing the rate of repeat TURP or reducing bleeding risk or improving voiding. Despite this, these medications are still commonly used in this setting.

The anecdotal use of 5ARIs for gross hematuria after a TURP should be re-evaluated. In our evaluation we did not find they led to a reduction in hospital visits for gross hematuria.