Experimental data support the concept of cavernosal damage and suggest a protective role for daily dosage of a PDE5-I ; however , similar data have not yet been replicated in humans .
Penile rehabilitation programs are common in clinical practice , but there is no definitive evidence to support their use or the best treatment strategy .
PDE5-Is are efficacious and safe in young patients with normal preoperative erectile function who have undergone bilateral nerve-sparing radical prostatectomy .
On-dem and use of a PDE5-I may be at least as efficacious as daily use .
PDE5-I use in penile rehabilitation programs is not supported by rigorous level 1 evidence -based medicine .
PDE5-Is are an efficacious and safe treatment for post-RP ED in properly selected patients .
The experimental results on the protective role of daily dosages of PDE5-Is , while robust , have not been replicated in humans .
CONTEXT  Erectile dysfunction ( ED ) after radical prostatectomy ( RP ) has a significant negative impact on a patient 's health-related quality of life .
Phosphodiesterase type 5 inhibitors ( PDE5-Is ) have recently been utilized not only as a treatment of ED in this population but also as a preventive strategy in penile rehabilitation programs .
OBJECTIVE To eluci date the pathophysiologic mechanisms of post-RP ED , to assess the need for rehabilitation following surgery , and to analyze the basic scientific evidence and clinical applications of PDE5-Is for the prevention and treatment of ED .
EVIDENCE SYNTHESIS Post-RP ED has many factors .
Cavernosal nerve injury induces pro-apoptotic factors ( ie , loss of smooth muscle ) and pro-fibrotic factors ( ie , an increase in collagen ) within the corpora cavernosa .
Clinical efficacy of sildenafil citrate based on etiology and response to prior treatment.
PURPOSE We assess the clinical efficacy of sildenafil citrate and predictors of satisfactory outcome . MATERIAL S AND METHODS All patients treated with sildenafil citrate within the first 6 weeks of its release were evaluated with a self-administered question naire before and at completion of therapy to assess etiology of erectile dysfunction , level of sexual function , libido , response to previous therapies , response to therapy with sildenafil citrate and quality of life . Sexual function was measured before and during therapy using an abbreviated version of the International Index of Erectile Function , with a successful outcome defined as a level of satisfaction of 4 or 5 on a 5-point scale . RESULTS Followup was obtained in 267 of the 308 patients who entered the study . Mean age plus or minus st and ard deviation was 61+/-9.6 years and duration of erectile dysfunction was 4.1+/-3 years .  Overall satisfaction with sildenafil citrate for the entire patient population was 65 % and response to prior therapies did not affect satisfaction . There was a significant positive correlation between baseline sexual function and response to sildenafil citrate but even patients with severe erectile dysfunction had a 41 % satisfaction rate . Etiology of erectile dysfunction had a significant impact on satisfaction rate , with neurogenic causes of erectile dysfunction ( diabetes , prostate surgery and so forth ) having significantly lower rates than psychogenic or vasculogenic erectile dysfunction . CONCLUSIONS Sildenafil citrate is a highly effective oral agent for the treatment of erectile dysfunction in clinical practice . The best predictors for response to sildenafil citrate therapy are baseline sexual function and etiology of erectile dysfunction . However , we could not identify any patient characteristic that would predict absolute failure for sildenafil citrate therapy . Therefore , all patients with erectile dysfunction who do not have specific contraindications should be considered for sildenafil citrate therapy
Experimental data support the concept of cavernosal damage and suggest a protective role for daily dosage of a PDE5-I ; however , similar data have not yet been replicated in humans .
Penile rehabilitation programs are common in clinical practice , but there is no definitive evidence to support their use or the best treatment strategy .
PDE5-Is are efficacious and safe in young patients with normal preoperative erectile function who have undergone bilateral nerve-sparing radical prostatectomy .
On-dem and use of a PDE5-I may be at least as efficacious as daily use .
PDE5-I use in penile rehabilitation programs is not supported by rigorous level 1 evidence -based medicine .
PDE5-Is are an efficacious and safe treatment for post-RP ED in properly selected patients .
The experimental results on the protective role of daily dosages of PDE5-Is , while robust , have not been replicated in humans .
CONTEXT  Erectile dysfunction ( ED ) after radical prostatectomy ( RP ) has a significant negative impact on a patient 's health-related quality of life .
Phosphodiesterase type 5 inhibitors ( PDE5-Is ) have recently been utilized not only as a treatment of ED in this population but also as a preventive strategy in penile rehabilitation programs .
OBJECTIVE To eluci date the pathophysiologic mechanisms of post-RP ED , to assess the need for rehabilitation following surgery , and to analyze the basic scientific evidence and clinical applications of PDE5-Is for the prevention and treatment of ED .
EVIDENCE SYNTHESIS Post-RP ED has many factors .
Cavernosal nerve injury induces pro-apoptotic factors ( ie , loss of smooth muscle ) and pro-fibrotic factors ( ie , an increase in collagen ) within the corpora cavernosa .