Return of Nocturnal Erections and Erectile Function after Bilateral Nerve-sparing Radical Prostatectomy in Men Treated Nightly with Sildenafil Citrate: Subanalysis of a Longitudinal Randomized Double-blind Placebo-controlled Trial

Authors


Andrew R. McCullough, MD, Director of Sexual Health, Fertility, and Microsurgery, New York University School of Medicine, 150 East 32 Street, 4D, New York, NY 10016, USA. Tel: (646) 825-6333; Fax: (646) 825 6397; E-mail: andy.mccullough@nyumc.org

ABSTRACT

Introduction.  After bilateral nerve-sparing radical retropubic prostatectomy (BNSRRP), nocturnal and sexually mediated erections may help to preserve normal erectile function (EF).

Aim.  To investigate nocturnal penile tumescence and rigidity (NPTR) in a subset (N = 54 men) from a randomized, double-blind trial (N = 76) of nightly sildenafil after BNSRRP.

Methods.  Inclusion required preoperative “normal” EF (defined as a combined score of ≥8 for International Index of Erectile Function questions 3 (penetration) and 4 (maintained erection after penetration) and NPTR testing (≥10 continuous minutes of ≥55% rigidity [R ≥ 55%] at the base). Postoperative assessments were at weeks 4 (pretreatment), 16, 28, 40 (during 36 weeks of nightly prophylaxis: sildenafil 50 mg [N = 17], 100 mg [N = 18] or placebo [N = 19]), and 48 (after 8 weeks of no erectile dysfunction therapy, when “responders” were delineated by the defined normal EF and a “yes” response to “Over the past 4 weeks, have your erections been good enough for satisfactory sexual activity?”). Base and tip rigidity and tumescence were measured using penile plethysmography.

Main Outcome Measures.  Duration of R ≥ 55% and area under the curves for rigidity and tumescence.

Results.  Postoperatively, rapid profound reduction in nocturnal EF was noted in all groups. There was a gradual dose-dependent improvement in base and tip rigidity in the sildenafil groups but little improvement in the placebo group. Eight weeks after treatment termination (48 weeks postoperatively), 24% (4/17) of 50-mg sildenafil recipients, 33% (6/18) of 100-mg sildenafil recipients, and 5% (1/19) of placebo recipients were responders. Tip R ≥ 55% was the most discriminating NPTR measure between nonresponders and responders to sildenafil, in whom it regained baseline (preoperative) levels (whereas base R ≥ 55% did not). It was most prolonged in responders to sildenafil 100 mg.

Conclusions.  In our subset analysis, nightly sildenafil for 9 months post-BNSRRP objectively improved nocturnal erections and pharmaceutically unassisted EF. McCullough AR, Levine LA, and Padma-Nathan H. Return of nocturnal erections and erectile function after bilateral nerve-sparing radical prostatectomy in men treated nightly with sildenafil citrate: Subanalysis of a longitudinal randomized double-blind placebo-controlled trial. J Sex Med 2008;5:476–484.

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