Nightly sildenafil use after radical prostatectomy has adverse effects on urinary convalescence: Results from a randomized trial of nightly vs on-demand dosing regimens

Introduction: This is a report on urinary function results from a randomized trial of nightly versus on-demand sildenafil after nerve-sparing radical prostatectomy (RP), a secondary objective. We analyzed the effects of these sildenafil administration schemes on urinary health-related quality of life after RP. Methods: In total, 100 potent men were equally randomized to nightly and on-demand sildenafil 50 mg after minimally-invasive RP for 1 year. Health-related quality of life questionnaires were administered at various postoperative intervals. Urinary function was assessed using appropriate expanded prostate cancer index composite (EPIC) subscales. Analyses of covariance and linear mixed-effects modeling were used to compare the effects of treatment over time on urinary recovery, controlling for age, nervesparing score, and time from surgery. Results: The nightly (n = 50) and on-demand (n = 50) sildenafil groups were well-matched at baseline. Nightly sildenafil patients had worse EPIC urinary bother and urinary irritative/obstructive subscale scores at 3 and 6 months after RP, even after controlling for multiple variables. On mixed-model analyses, the differences between groups for these EPIC subscales (4.9 and 2.5, respectively) were greater than documented thresholds for clinical significance. Increasing nerve-sparing score was associated with improvements in EPIC urinary summary, bother, incontinence, and function scores; time from surgery was associated with improvements in all EPIC urinary health-related quality of life subscales. Conclusions: In this specific population and drug dose, we found that on-demand short-acting phosphodiesterase-5 inhibitor (PDE5i) dosing may be more effective after RP to maximize early urinary health-related quality of life. In preoperatively potent men, nightly sildenafil 50 mg impaired urinary health-related quality of life more than on-demand use in the early months after nerve-sparing RP, independent of effects on urinary continence.