Pharmacological Penile Rehabilitation in the Preservation of Erectile Function Following Bilateral Nerve-Sparing Radical Prostatectomy

Inclusion Criteria:

* Male, must be ≥ 18 years of age, with histologically confirmed prostate adenocarcinoma, that is clinically localized to the prostate gland
* Stable sexual relationship for ≥ 6 months
* Open or laparoscopic bilateral nerve-sparing radical prostatectomy
* Baseline score of ≥ 22 on the International Index of Erectile Function Domain (Appendix A)
* Able to speak, read and write in the English language
* Calculated creatinine clearance using the 4 variable MDRD equation based on serum creatinine, age, race, and gender of \> 60 cc/min
* Patient is able to walk up two flights of stairs briskly without chest pain
* Patient needs to have their baseline sitting AND standing blood pressure and pulse done at the time of consent

Exclusion Criteria:

* Preoperative or planned postoperative pelvic radiation therapy
* Preoperative or planned postoperative androgen deprivation
* Presence of Peyronie's disease at baseline
* Presence of a penile prosthesis at baseline
* Resection of one or both nerve bundles at surgery
* Any contraindications to sildenafil:

  * Patient is currently using nitrates;
  * Presence of retinitis pigmentosa;
  * Presence macular degeneration;
  * MI or CVA within 3 months;
  * Patient is currently using MAOI medications
* Patient is currently using penile self injection medication (Trimix, Bimix, or PGE-1)
* Patient requiring sildenafil for penetration
* Use of sildenafil within 30 days of consent