Efficacy and safety of sildenafil citrate in hemodialysis patients

Erectile dysfunction (ED) is more frequent among end-stage renal failure patients than the normal population. Sildenafil citrate has been successfully used for the symptomatic treatment of erectile dysfunction. The aim of this study was to determine the efficacy and safety of sildenafil citrate in the treatment of ED in patients on hemodialysis. Fifty-five hemodialysis patients above 18 years suffering from ED with steady sexual partners were included in the study. The first five and fifteenth questions of the International Index of Erectile Function were employed to evaluate ED in the patient group. A Single 50-mg sildenafil citrate tablet was prescribed for each patient. The patients were encouraged to take it on the day after hemodialysis and 1 hour before sexual intercourse. The erectile function of the patients after the treatment was re-evaluated in the same manner by International Index of Erectile Function. The ages of the patients ranged between 30 and 73 years (mean 50.6 +/- 10.9). The overall response rate was 74.5% (38/51). Side effects were nausea (n = 2), palpitation (n = 2), flushing (n = 1), and angina (n = 1). Sildenafil citrate (50 mg) was observed to be safe and effective for treatment of hemodialysis patients with careful evaluation and proper patient selection.     

Efficacy of sildenafil citrate in prostate brachytherapy patients with erectile dysfunction

Objectives. To ascertain the efficacy of sildenafil citrate (Viagra) in patients with erectile dysfunction (ED) either before or after prostate brachytherapy by an open-label, nonrandomized study.Methods. Sixty-two patients who underwent prostate brachytherapy between March 1995 and July 1998, had ED either before or after brachytherapy, and were interested in treatment with sildenafil comprised the patient population. Clinical and treatment parameters evaluated for medication efficacy included patient age at brachytherapy and at medication administration, hypertension, diabetes, smoking history, onset of ED, potency status before implant, frequency of intercourse before brachytherapy (if potent), use of neoadjuvant hormonal manipulation, use of moderate dose external beam radiation therapy before implantation, choice of isotope, V100 (the percentage of the prostate volume receiving at least 100% of the prescribed minimal peripheral dose), and sildenafil dose.Results. Fifty (80.6%) of 62 patients responded favorably to sildenafil. None of the treatment parameters predicted medication failure, and among the clinical parameters, only diabetes predicted failure (3 of 5) and only with borderline statistical validity (P = 0.046).Conclusions. Our results suggest brachytherapy-induced impotence is as amenable to sildenafil treatment as ED from other causes. In addition, our 80.6% success rate is comparable to reported results for patients who underwent bilateral nerve-sparing radical prostatectomy and significantly better than patients who underwent unilateral nerve-sparing or non-nerve-sparing approaches.     

Efficacy of sildenafil citrate in treatment of erectile dysfunction: effect of type 2 diabetes

PURPOSE: To assess efficacy of sildenafil citrate in treatment of erectile dysfunction: effect of type 2 diabetes. MATERIALS AND METHODS: A total of 466 male patients with erectile dysfunction (ED) were enrolled in this study. Of them 382 were diabetic and 84 were non-diabetic. Patients were screened for ED using the erectile function domain of the International Index for Erectile Function (IIEF). Patients underwent routine laboratory investigations, in addition to total testosterone and prolactin assessment. To assess the effect of diabetes on efficacy of sildenafil, we compared the pre and post sildenafil responses to erectile function domain, Q3, Q4. Overall satisfaction and global efficacy question (GEQ) were also assessed. RESULTS: Mean age +/- S.D. was 53 +/- 8.4 and 49.7 +/- 10.6 years for patients with and without diabetes respectively. There were significant associations between increased severity of ED and longer duration, poor metabolic control and presence of more than one diabetes-related complication (p < 0.05 for each). Differences were significant between pre and post sildenafil administration regarding erectile function domain, Q3, Q4 (p < 0.05 for each). In the non-diabetic patients the GEQ and the overall satisfaction were significantly higher than in diabetics (p < 0.05 for each). Global efficacy question was significantly low in patients with fair and poor metabolic control, longer duration of diabetes, and patients with diabetic complications (p < 0.05 for each). CONCLUSIONS: Sildenafil is an effective treatment for diabetic patients with ED. Although the efficacy of sildenafil was negatively affected by factors as poor control and longer duration of diabetes and presence of more than one diabetes-related complication, however, the global efficacy and the overall patients' satisfaction were high.     

Efficacy, safety and patient acceptance of sildenafil citrate as treatment for erectile dysfunction

PURPOSE: We assessed the efficacy and safety of sildenafil citrate as treatment for erectile dysfunction. MATERIALS AND METHODS: A total of 433 completely evaluated men with chronic erectile dysfunction were treated with sildenafil citrate. Response was assessed prospectively by baseline and followup physician interviews, and by a patient self-administered 15-item questionnaire on the domains of patient treatment response and satisfaction, partner treatment satisfaction, comparative previous treatment satisfaction, adverse effects, and patient and partner quality of life. RESULTS: Of the 304 men (70.2%) who completed the questionnaire 278 received sildenafil, including 186 who previously had undergone treatment for erectile dysfunction, principally involving intracavernous injection therapy. A response was elicited by a median dose of 100 mg. in 188 patients (67.6%) who achieved erection suitable for sexual intercourse. Those with psychogenic erectile dysfunction responded significantly better than those with organic dysfunction (p <0.001). Erection suitable for intercourse was attained by 30.8% of patients with erectile dysfunction after radical prostatectomy and 80% with cavernous veno-occlusive dysfunction. Of previous intracavernous injection responders 29.9% were refractory to sildenafil, while 33. 3% of previous intracavernous injection nonresponders responded to sildenafil. The sildenafil response was considered inferior to the intracavernous injection response by 43.6% of the men who previously responded to intracavernous injection, of whom 51.5% continued to receive intracavernous injection as the only treatment (19.5%) or as an alternative to sildenafil (32%). Adverse effects in 53.6% of cases were assessed as mild in 56.4%, moderate in 38.3% and severe in 5.3%. Multiple adverse effects were reported by 62.4% of patients, while 17 (6.1%) discontinued sildenafil as a direct result of intolerable adverse effects. The most common adverse effects were facial flushing in 33.5% of cases, headaches in 23.4%, nasal congestion in 12.6%, dyspepsia in 10.1% and dizziness in 10.8%. Baseline patient and partner quality of life scores significantly improved after sildenafil treatment (p <0.001), while significantly improved quality of life was noticed by 51.5% and 43.1%, respectively. CONCLUSIONS: Sildenafil citrate is effective oral first line treatment for erectile dysfunction. Although more than 50% of men reported adverse effects, most were considered mild and rarely resulted in treatment cessation. There was a trend in those on intracavernous injection who responded to sildenafil to continue intracavernous injection as the only therapy or as an alternative to sildenafil. Also, we noted that some cases refractory to sildenafil responded to intracavernous injection. These findings imply that intracavernous injection remains an effective erectile dysfunction treatment option.     

Efficacy of sildenafil in erectile dysfunction after radical prostatectomy

Radical retropubic prostatectomy (RRP) is an important cause of iatrogenic erectile dysfunction (ED). While sildenafil has been widely used since its introduction as a new treatment option for ED, its efficacy in post-RRP patients has not been extensively studied. We retrospectively compared the efficacy of sildenafil in post-RRP and non-surgical patients with ED (NSED) using a subset of questions from the International Index of Erectile Function (IIEF) and correlated results with their specific etiology of ED based on penile blood flow study (PBFS). A brief questionnaire regarding satisfaction with sildenafil was administered to 72 consecutive post-RRP patients (nerve sparing status unknown) and 32 consecutive NSED patients who had previously undergone PBFS with pharmacotesting as part of their evaluation for ED. PBFS diagnoses were arterial insufficiency (AI) for peak systolic velocity (PSV) < 25 cm/sec; venogenic (CVOD) for PSV > or = 35 cm/sec, mixed vascular for PV > 25 but < 35 cm/sec and resistive index (RI) < 0.9; a vascular normal diagnosis (neurogenic impotence) required excellent rigidity sustained for 20 min. Differences in the IIEF subscores for the different groups of patients were assessed. Success with sildenafil was defined as moderate or excellent improvement (3/4 or 4/4) with ability for penetration. No differences were found among the different subgroups of RRP patients with respect to IIEF scores or success rates with sildenafil. NSED patients had both significantly higher post-treatment IIEF scores (3.6/3.4 vs 2.5/2.2; t=4.50, P<0.0001) and success rates (63% vs 31%; t=3.11, P < 0.01) with sildenafil treatment than RRP patients. We found that sildenafil is significantly less effective in impotent RRP patients than in age-matched patients with ED (31% vs 63%). We had postulated that sildenafil would be least effective among RRP patients with excellent sustained rigidity to PGE1, as this subgroup is likely to have neurogenic impotence. We found that sildenafil response rates among subgroups of RRP patients were statistically similar regardless of PBFS diagnosis. IIEF scores for the RRP subgroups were similar but statistically lower than in men with ED and no history of RRP. While individuals with normal vascular responses to PGE1 have an increased likelihood of having neurogenic impotence, in RRP patients, we were unable to demonstrate any difference in efficacy of sildenafil, regardless of the PBFS diagnosis.     

Tadalafil improved erectile function at twenty-four and thirty-six hours after dosing in men with erectile dysfunction: US trial

In a previous study assessing tadalafil for the treatment of erectile dysfunction (ED), tadalafil 20 mg was shown to improve erectile function for up to 36 hours vs placebo. This study sought to demonstrate the effectiveness of both 10- and 20-mg tadalafil vs placebo at 2 prespecified assigned times of 24 and 36 hours postdosing. This double-blind, placebo-controlled, parallel-group study randomized 483 men with ED into 6 groups according to a combination of treatment (placebo, tadalafil 10 or 20 mg) and assigned time (24 or 36 hours) for intercourse attempts. Patients were stratified by baseline ED severity based on Erectile Function Domain scores. The study had 4 phases: a 4-week run-in (no ED medication taken); a 2- to 4-week equilibration (dosing as needed); a 4- to 6-week assessment; and a 6-month open-label extension. During the assessment phase, men took a total of 4 doses of study medication, each dose separated by more than or equal to 7 days. Efficacy was measured as the mean per-patient percentage of successful intercourse attempts (Sexual Encounter Profile Diary Question 3: SEP3) during the assessment phase. Men taking either 10- or 20-mg tadalafil had a significant increase in SEP3 from baseline scores vs placebo at both 24 hours (P = .038 and <.001 for 10 and 20 mg, respectively) and 36 hours (P < .001 for both doses) postdose. The mean per-patient percentages of successful intercourse attempts for the 24-hour time point were 41.8%, 55.8%, and 67.3% for placebo and tadalafil 10 and 20 mg, respectively; for the 36-hour time point, the mean per-patient percentages were 32.8%, 56.2%, and 61.9% for placebo and tadalafil 10 and 20 mg, respectively. The most common treatment-emergent adverse events were headache, back pain, dyspepsia, and nasopharyngitis. Both 10- and 20-mg tadalafil improved erectile function for up to 36 hours postdosing in men with ED of varied severity.     

Efficacy of sildenafil as the first-step therapeutic tool for Japanese patients with erectile dysfunction

The aim of this study was to assess the efficacy of sildenafil as the first-step tool for erectile dysfunction (ED) in Japanese males. Between March 1999 and March 2003, 281 patients were prescribed five tablets of sildenafil (50 mg) as the first step in the therapeutic management of ED. Of the 281 patients, 206 were evaluable patients. The overall success rate in achieving sexual intercourse in subjects after taking sildenafil was 77.2% (159/206), while 22.8% (47/206) were unsuccessful. The success rates in men with functional ED and organic ED were 91.4% (85/93) and 65.5% (74/113), respectively (P<0.0001). Overall, transient adverse effects of sildenafil occurred in 16 (8%) males. Intolerable adverse effects (edema and dizziness) occurred in only 1% of patients (2/206). Sildenafil citrate may be recommended as the first choice drug for ED because of its high success rate and low invasiveness.     

Role of sildenafil citrate in treatment of erectile dysfunction after radical retropubic prostatectomy

BACKGROUND: Sildenafil citrate was introduced as a treatment for erectile dysfunction in April 1998 in the United States and has been available since March 1999 in Japan. In this article, we assess the efficacy of sildenafil in the treatment of erectile dysfunction in Japanese men after radical retropubic prostatectomy for localized prostate cancer. METHODS: Of 106 men who underwent radical retropubic prostatectomy between January 1994 and March 2000, 43 were prescribed sildenafil at their request after radical retropubic prostatectomy. Medication was initiated at 25 mg, and if this was ineffective, the dose was increased to 50 mg. Of the patients, 18 underwent bilateral and 21 unilateral nerve sparing (NS) procedures, while in 4 patients, a non-NS procedure was performed. These patients were interviewed using a questionnaire about their response to sildenafil and using the 5-item International Index of Erectile Function (IIEF-5) questionnaire. RESULTS: Thirty-three of the 43 patients were eligible for evaluation of the efficacy of sildenafil and 27 completed the IIEF-5 questionnaires. Sildenafil at 50 mg had a better effect on sexual function than 25 mg in most Japanese patients. Of the 16 patients who underwent bilateral NS procedures, 10 (62.5%) had improved ability for intercourse and 3 (18.8%) had improved erections. Of the 13 patients who underwent unilateral NS procedures, 7 (53.8%) had improved ability for intercourse and 4 (30.8%) had improved erections. None of the 4 patients who underwent non-NS procedures had a positive response. Of 24 patients with positive response to sildenafil, 3 (12.5%) did not have to take sildenafil after receiving it because they did not require it for intercourse. Mean IIEF-5 score increased from 4.3 to 11.4 (P < 0.0001). Patient age, time since surgery, PSA and pathological stage did not have statistically significant effects on outcome. The most commonly cited adverse effect was headache (21%). CONCLUSION: Sildenafil is equally effective for erectile dysfunction in Japanese patients who have undergone bilateral and unilateral NS procedures, and aids recovery of natural erectile function after radical retropubic prostatectomy. However, non-NS procedure patients had no response to sildenafil. This study suggested that sildenafil is well tolerated and should be initially used for treatment of Japanese men with erectile dysfunction after radical retropubic prostatectomy.     

Treatment of erectile dysfunction after radical prostatectomy with sildenafil citrate (Viagra)

Objectives. To determine whether the response to the new oral medication, sildenafil citrate (Viagra), was influenced by the presence or absence of the neurovascular bundles, as recent reports on its success did not specify the efficacy of the drug in patients with erectile dysfunction after radical prostatectomy.Methods. Baseline and follow-up data from 28 healthy patients presenting with erectile dysfunction after radical prostatectomy were obtained. Patients receiving any neoadjuvant/adjuvant hormones or adjuvant radiation therapy were excluded. Patients reported what their erectile status was before surgery, before sildenafil therapy, and after using a minimum of four doses of sildenafil. Both the patients and their spouses were interviewed using the Cleveland Clinic post-prostatectomy questionnaire, which includes questions about response to therapy, duration of intercourse, spousal satisfaction, side effects, and related topics. The patients were compared on the basis of the type of surgical procedure they had undergone—nerve sparing or non-nerve sparing. A positive response to sildenafil was defined as erection sufficient for vaginal penetration.Results. Of the 15 patients who had bilateral nerve-sparing procedures, 12 (80%) had a positive response to sildenafil, with a mean duration of 6.92 minutes of vaginal intercourse. These 12 patients also reported a spousal satisfaction rate of 80%. All 12 of the responders had a positive response within the first three doses, and 10 of the 12 responded with the first or second dose. None of the 3 patients who had undergone a unilateral nerve-sparing procedure responded, nor did any of the 10 patients who had undergone a non-nerve-sparing procedure. The two most common side effects of the drug were transient headaches (39%) and abnormal color vision (11%). No patients discontinued the medication because of side effects.Conclusions. Successful treatment of erectile dysfunction in a patient after prostatectomy with sildenafil citrate may depend on the presence of bilateral neurovascular bundles. No patient who had undergone a non-nerve-sparing procedure responded. Whether patients who undergo unilateral nerve-sparing procedures will respond to sildenafil is still unclear because of the small number of patients in our study. These findings should encourage urologists to continue to perform and perfect the nerve-sparing approach. The ability to restore potency with an oral medication after radical prostatectomy will impact our discussion with the patient on the surgical morbidity of radical prostatectomy.     

Dose-dependent protective effect of sildenafil citrate on testicular injury after torsion/detorsion in rats

This experiment was designed to investigate the effect of sildenafil citrate on testicular injury after unilateral testicular torsion/detorsion (T/D). Thirty-seven adult male Wistar albino rats were divided into four groups: sham operated group (group 1), T/D+ saline (group 2), T/D+ 0.7 mg sildenafil citrate (group 3) and T/D+ 1.4 mg sildenafil citrate (group 4). Testicular torsion was created by rotating the right testis 720° in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. The level of GSH (P < 0.05) in the testis in the group 2 were significantly lower (P < 0.05) and the levels of MDA and NO (P < 0.01 for both) in the testis were significantly higher when compared with those of the group 1. Administration of low dose sildenafil citrate prevented the increases in MDA and NO levels and decreases in GSH values induced by testicular torsion. However, administration of high dose sildenafil citrate did not have any effect on these testicular tissue parameters (P > 0.05). Also, mean values of seminiferous tubules diameters, germinal cell layer thicknesses and mean testicular biopsy score were significantly better in group 3 than groups 2 and 4. These results suggest that T/D injury occurred in testis after unilateral testicular T/D and that administration of low dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular torsion. Sildenafil citrate probably acts through reduction of reactive oxygen species and support antioxidant enzyme systems.