Study of Sildenafil Citrate During and After Radiotherapy/Hormone Therapy for Erectile Function Versus Radiotherapy/Hormone Therapy for Prostate Cancer

"Hormone therapy patients will be instructed to begin the study drug simultaneously or within 1 month of start of hormone therapy. These patients will then continue to take the study drug for approximately 6 months following start of radiotherapy.In addition, during prophylactic phase (drug and placebo prophylactic arms) patients will have the opportunity to utilize oral 50 mg. tablets of Sildenafil Citrate in an on demand open label, flexible dose fashion. Hormone patients will be offered on demand Sildenafil for approximately 15-21 months.~Hormone therapy patients will complete assessments at baseline (within 4 weeks of start of study treatment) each month (only IIEF and QOL) before start of radiotherapy, at start of radiotherapy and at months 3, 6, 9, 12 18 and 24 from start of radiotherapy. Testosterone assessments will take place at baseline, and months 12 and 24."

"Non-hormone therapy patients will be instructed to begin the study drug 3 days prior to start of radiotherapy. Patients beginning study drug anytime between 3 days before start of radiotherapy and 2 weeks after the first day of radiotherapy will also be acceptable. These patients will then continue to take the study drug for approximately 6 months following start of radiotherapy.~In addition, during prophylactic phase (drug and placebo prophylactic arms) patients will have the opportunity to utilize oral 50 mg. tablets of Sildenafil Citrate in an on demand, open label, flexible dose fashion. Non-hormone patients will be offered on demand Sildenafil for approximately 12 months.~Assessments (IIEF, IPSS, QOL) will be completed by non-hormone therapy patients at baseline (within 4 weeks of start of study treatment) and at approximately months 3, 6, 9, 12, 18 and 24 from start of radiotherapy. Testosterone assessments will take place at baseline, and months 12 and 24."