Efficacy and safety of flexible-dose oral sildenafil citrate (Viagra) in the treatment of erectile dysfunction in Brazilian and Mexican men

A 12-week, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of flexible-dose sildenafil citrate (Viagra) treatment (25, 50 or 100 mg) in Brazilian and Mexican men with erectile dysfunction (ED) of broad-spectrum etiology. Efficacy was assessed on the basis of responses to the 15-item International Index of Erectile Function (IIEF) questionnaire, completed at baseline and after 12 weeks of treatment. At end point, mean scores for all IIEF domains of sexual function (erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction) were significantly (P<0.0001) higher in the sildenafil group (n=109) than in the placebo group (n=105). These findings confirm the significant increases in frequency of penetration and frequency of maintained erections reported previously. Sildenafil treatment was well tolerated. The most common adverse events were headache and flushing. In conclusion, sildenafil is a well-tolerated and effective treatment for ED of broad-spectrum etiology in Latin American men.     

Assessment of the efficacy and safety of Viagra (sildenafil citrate) in men with erectile dysfunction during long-term treatment

Long-term efficacy and safety of sildenafil was assessed in 1008 patients with erectile dysfunction (ED) enrolled in four flexible-dose (25 - 100 mg), open-label, 36- or 52-week extension studies. After 36 and 52 weeks, 92% and 89% of patients felt that treatment with sildenafil had improved their erections. Responses to a Sexual Function Questionnaire indicated that 52 weeks of sildenafil treatment resulted in clinically significant improvements in the duration and firmness of erections, overall satisfaction with sex life, and the frequency of stimulated erections. Commonly reported adverse events (AEs) were headache, flushing, dyspepsia, and rhinitis, which were generally mild to moderate. Reports of abnormal vision were consistent with previous clinical trials. The occurrence of treatment-related cardiovascular AEs, such as hypertension, tachycardia, and palpitation, was <1%. Discontinuations due to treatment-related AEs were low (2%). Long-term therapy does not diminish the efficacy of sildenafil in patients with ED and remains well tolerated.     

Sildenafil citrate (Viagra) for the treatment of erectile dysfunction in Nigerian men

Fifty-eight Nigerian outpatients with documented erectile dysfunction (ED) received open-label sildenafil citrate (Viagra) for 8 weeks. The 50-mg starting dose could be adjusted to 100 or 25 mg based on response and tolerability. The International Index of Erectile Function (IIEF) Questionnaire, a global efficacy question, and intercourse data recorded in a patient event log were used to assess efficacy. Frequency of penetration and maintained erection were both significantly enhanced (P<0.0001); 95% of patients reported improved erections and 81% of all attempts at intercourse were successful. Orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction also improved significantly (P&<0.0001). The most frequent adverse events (all-cause) were headache (17%) and myalgia (3%); only one patient discontinued treatment because of headache, which was considered unrelated to sildenafil. Oral sildenafil significantly improved erectile function and was well tolerated in this trial of Nigerian men suffering from ED. Our results are consistent with reports from other countries.     

Long-term efficacy and safety of oral Viagra (sildenafil citrate) in men with erectile dysfunction and the effect of randomised treatment withdrawal

The long-term efficacy and safety of oral Viagra (sildenafil citrate), a selective phosphodiesterase 5 inhibitor, and the effect of withdrawing treatment were evaluated in men with erectile dysfunction (ED). In 233 men with ED of psychogenic or mixed organic/psychogenic aetiology, 16 weeks of open-label, flexible-dose sildenafil treatment (10-100 mg) was followed by eight weeks of double-blind, fixed-dose, randomised withdrawal to placebo or continued treatment with sildenafil. Sildenafil was taken as needed (not more than once daily) approximately 1 h prior to sexual activity. The main outcome measures were a global efficacy question, a sexual function questionnaire, an event log of erections, and adverse event recording. In the open-label phase, 200 of 216 patients (93%) reported improved erections with sildenafil; 28 patients (12%) discontinued treatment. In the double-blind phase, the significant improvements in the frequency and duration of erections were maintained in the sildenafil group but returned to pre-treatment values in patients on placebo (P values < 0.0001 versus placebo). The most frequent adverse events in the sildenafil group during the double-blind phase were flushing (7%), headache (6%), and dyspepsia (5%). Of the 192 patients enrolled in the 1-y extension, 90% completed the study; only two patients (1%) were withdrawn due to lack of efficacy. In men with ED of psychogenic or mixed aetiology, oral sildenafil is effective and well-tolerated both at the initiation of therapy and during long-term treatment. For most patients, sildenafil treatment must be continued for improvements in erectile function to be maintained.     

Comparison of the efficacy and safety of sildenafil citrate (Viagra) and oral phentolamine for the treatment of erectile dysfunction

This open-label, multi-center study from Mexico compared the efficacy and safety of oral sildenafil and phentolamine in men with erectile dysfunction. Patients received sildenafil (25-100 mg; n=123) or phentolamine (40 mg; n=119) for 8 weeks, and efficacy was assessed using the International Index of Erectile Function (IIEF) as well as two global efficacy questions. Mean scores for the erectile function domain of the IIEF were significantly higher for sildenafil (27.23 +/- 0.62; P=0.0001) than for phentolamine (19.35 +/- 0.66). Approximately twice as many men receiving sildenafil had successful attempts at sexual intercourse (88% vs 42%), improved erections (95% vs 51.1%), and improved ability to have sexual intercourse (94.4% vs 46.4%) compared with phentolamine. The most common adverse events included rhinitis, headache, tachycardia, and nausea, with a higher frequency reported in patients receiving phentolamine than sildenafil (41% vs 33%), with the exception of headache, which was reported more frequently in sildenafil users. Overall, sildenafil was more effective and appeared to be better tolerated than phentolamine for the treatment of erectile dysfunction.     

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.     

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.     

Quality of life in patients with spinal cord injury receiving Viagra (sildenafil citrate) for the treatment of erectile dysfunction

STUDY DESIGN: A multicenter, randomized, double-blind, placebo-controlled, flexible-dose, two-way crossover study conducted June 1996 through January 1997. OBJECTIVES: To evaluate the effect of sildenafil citrate (VIAGRA(R)) on the quality of life (QoL) of men with erectile dysfunction (ED) caused by spinal cord injury (SCI). SETTING: Study centers in Australia, Belgium, France, Germany, Norway, Sweden and the United Kingdom. METHODS: Questions 13 and 14 of the 15-item International Index of Erectile Function (IIEF) addressed QoL issues directly related to ED in 178 men with SCI. A 5-item questionnaire addressing concerns that men had about their erection problems was also used to evaluate the impact of ED on QoL. Several commonly used psychometric instruments, including the Medical Outcomes Survey (MOS) Short Form-12, Psychological General Well-Being Index, and MOS Family Survey, assessed general QoL issues. RESULTS: Significant improvements were seen for overall satisfaction with sex life (IIEF Q13), sexual relationship with partner (IIEF Q14), and concerns about erectile problems (P<0.0001). Improvements were reported in scores for the generic QoL parameters of mental health, well-being, depression, and anxiety (P<0.05 sildenafil versus placebo). CONCLUSION: Treatment with sildenafil can significantly improve key QoL parameters in men with ED caused by SCI. Sponsorship: This study was funded by Pfizer Inc. Spinal Cord (2000) 38, 363 - 370.     

安特尔加枸橼酸西地那非治疗中老年勃起功能障碍的价值

目的探讨安特尔加枸橼酸西地那非治疗男性勃起功能障碍的价值.方法随机开放120名受试者在2周筛选期后进入4周的治疗期,A组安特尔加枸橼酸西地那非,安特尔120mg/d,枸橼酸西地那非4周内至少服用4次.B组单用枸橼酸西地那非.在筛选期及研究结束时填写国际勃起功能问卷(ⅡEF).研究者根据受试者记事表、ⅡEF和总评题对受试者进行疗效评价.结果增加安特尔后并不提高枸橼酸西地那非的临床总有效率,总评题及性交成功率,但明显改善了病人的性欲,提高了性满足感及性高潮的次数,两组差距有统计学意义.服药后无严重不良事件发生.结论对于性欲较低的ED患者,安特尔加枸橼酸西地那非治疗是有价值的.     

Indications and early results of sildenafil (Viagra) in erectile dysfunction

Objectives. To assess the acceptability, feasibility, and early results of sildenafil (Viagra) in a nonselected cohort of 316 patients (median age 58 years) who sought treatment for male sexual dysfunction during a 10-week period.Methods. Erectile status and activity were evaluated by questionnaire; erectile function was assessed by pharmacologic testing and visual sexual stimulation. Cardiovascular contraindications were assessed. Patients selected for the trial received treatment for 2 months. Results based on the possibility of penetration and individual satisfaction (scale from 0 to 10) were classified as good, fair, or bad. Multifactorial analysis was performed to define factors influencing the response to sildenafil.Results. Twenty-five percent of the patients from the initial cohort refused or did not meet the criteria for oral treatment; 25% of the remaining had a cardiovascular contraindication. At the end of the trial, 157 patients (88.7%) had completed the study; the efficacy of and satisfaction with sildenafil were considered good for 50 (31.84%), fair for 46 (29.29%), and bad for 61 (38.85%). Spontaneous nocturnal erections, organic etiologies, especially cavernovenous impotence, and previous treatment with self-intracavernous injections were significant factors influencing responses to oral treatment. Finally, 32% of the patients after completing the trial (17.2% of the initial cohort) were using sildenafil as their sole treatment, 34% chose self-intracavernous injections, and 25% decided to alternate between oral and local therapy.Conclusions. In the present study, sildenafil had a 60% efficacy rate and was chosen as the sole treatment by only 30% of the patients tested. We propose pretreatment tests to help to predict the response to this medication.     

Efficacy and safety of oral sildenafil citrate (Viagra) in the treatment of male erectile dysfunction in Colombia,Ecuador, and Venezuela: a double-blind,multicenter, placebo-controlled study

The objective of this work was to assess the efficacy and safety of sildenafil in patients with erectile dysfunction (ED) from Colombia, Ecuador, and Venezuela. One hundred and fifty-eight outpatients with ED participated in a double-blind, flexible-dose, randomized-controlled trial. Efficacy measures included question 3 (achieving an erection) and question 4 (maintaining an erection) from the International Index of Erectile Function (IIEF), the five functional domains of the IIEF, a global efficacy question, and patient event log. Sildenafil increased patients' ability to achieve/maintain erections (P<0.01). Seventy-seven per cent of sildenafil- vs 46% of placebo-treated patients reported improved erections (P<0.001). Sixty-five percent and 35% of intercourse attempts were successful among sildenafil and placebo patients, respectively (P<0.05). Sildenafil patients showed significant improvements in three of the five IIEF functional domains (P<0.05). Adverse events were reported for 51% and 33% of sildenafil and placebo patients, respectively. It can be concluded that sildenafil is an effective, well-tolerated treatment for ED in patients from Latin America.     

A dose-escalation study to assess the efficacy and safety of sildenafil citrate in men with erectile dysfunction

OBJECTIVE: To assess the efficacy and safety of sildenafil citrate (Viagra, Pfizer Inc., USA) in a double-blind, placebo-controlled, dose-escalation study over a period of 26 weeks in men with erectile dysfunction of a broad spectrum of aetiology. PATIENTS AND METHODS: In all, 315 patients from five countries were randomized to receive treatment with placebo (156 men) or sildenafil (159 men). Significant concomitant medical conditions were hypertension (20%), a history of pelvic surgery (19%), diabetes mellitus (15%), and ischaemic heart disease (10%). Patients randomized to treatment received a starting dose of 25 mg of sildenafil or matching placebo, which could be increased to 50 mg and then to 100 mg of sildenafil, based on efficacy and tolerability. Assessments of efficacy comprised the 15-item International Index of Erectile Function (IIEF), including question three (ability to achieve an erection) and question four (ability to maintain an erection), a partner questionnaire, an overall efficacy question, and event-log data. RESULTS: After 12 weeks of treatment, 26%, 32% and 42% of patients were taking 25, 50 and 100 mg of sildenafil, respectively. A similar distribution of doses was reported after 26 weeks of treatment. Treatment with sildenafil significantly improved the patients' abilities to achieve and maintain an erection compared with treatment with placebo (P < 0.001). Scores for four of the five sexual function domains of the IIEF (erectile function, orgasmic function, intercourse satisfaction and overall satisfaction) also improved significantly (P < 0.001). There was a significant improvement in the mean score for the erectile function domain, regardless of the aetiology of erectile dysfunction (P < 0.001). After 12 weeks and 26 weeks of treatment, 82% and 79% of patients receiving sildenafil reported improved erections, compared with 24% and 23% of patients receiving placebo, respectively (P < 0.001). Treatment-related adverse events were mild to moderate and occurred in 27% of patients receiving sildenafil, compared with 8% of patients receiving placebo. CONCLUSION: Sildenafil is an effective and well-tolerated treatment for men with erectile dysfunction of a broad spectrum of aetiology.     

Efficacy and safety of sildenafil citrate for treatment of erectile dysfunction in a population with associated organic risk factors.

The objective of this study was to determine the efficacy and safety of sildenafil in patients with erectile dysfunction (ED) and associated organic risk factors in a multispecialty clinic. Patients (n = 521) were diagnosed with ED based on self-assessment. Associated risk factors were managed by medication or life-style modifications, or both, before treatment with sildenafil for ED. Patients received a 50-mg dose of sildenafil that could be adjusted to 100 mg or 25 mg based on tolerability and efficacy. Patients recorded the number of successful intercourse encounters for 6 to 8 weeks, and the number of adverse events. Overall, there was an 82% successful intercourse rate with sildenafil treatment. The predominant associated risk factors for ED were hypertension (39%), hypogonadism (37%), and multiple medications (34%). Common adverse events due to sildenafil treatment were mild to moderate in nature and resulted in <2% patient discontinuation. Clinicians should be particularly careful to evaluate patients presenting with ED because the condition can be accompanied by a wide spectrum of risk factors requiring monitoring and treatment. However, with adequate treatment and control of these risk factors, the use of sildenafil in a representative population of men with ED in a multispecialty clinic can achieve a higher efficacy rate than previous studies have indicated.     

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 and safety of oral sildenafil in men with erectile dysfunction and spinal cord injury

OBJECTIVE: To assess the efficacy of sildenafil in men with spinal cord injury (SCI) and erectile dysfunction (ED). METHODS: Seventeen men with SCI were selected from February to September 1998 for sildenafil treatment of ED. The initial dose of 25 mg was increased by 25-mg increments as needed. Patients underwent baseline physical examination and answered questions from the abridged International Index of Erectile Function before and during therapy. RESULTS: Sixteen patients tolerated therapy; 1 developed hypotension and discontinued therapy. There was significant improvement in erectile function (P < .05) after 5.3 +/- 2.2 months when compared with baseline or previous therapies (P < .05). Of the 17 patients, 94% recommended sildenafil to others. Six of these 16 patients were available for long-term follow-up. There was further significant improvement in quality of erection (P < .05), but no change in satisfaction. CONCLUSION: Sildenafil is effective and well tolerated in men with SCI and ED.     

A baseline-controlled,open-label,flexible dose-escalation study to assess the safety and efficacy of sildenafil citrate (Viagra) in patients with erectile dysfunction

Although sildenafil citrate (Viagra) has demonstrated effectiveness in the treatment of erectile dysfunction (ED), the dosing regimens often used in clinical trials may not always match those employed in clinical practice. This study was undertaken to further assess the efficacy and safety of sildenafil taken as required in male outpatients 18 years of age and older with ED (n=71). It was conducted as a placebo-baseline-controlled, open-label, flexible dose-escalation study, with sildenafil (25,50, or 100 mg) administered for 8 weeks following a 4-week placebo run-in. Efficacy variables included questions 3 and 4 of the International Index of Erectile Function (IIEF), other IIEF domains, patient event logs, and quality-of-life (QOL) assessments. Treatment with sildenafil resulted in improvements from baseline in all IIEF domains analyzed (all P<0.0001), as well as overall QOL and amelioration of specific sexual and social relationships (all P&<0.0001). Sildenafil was well tolerated. One participant discontinued treatment because of adverse events. Results suggest that flexible dosing with oral sildenafil is safe and has beneficial effects on all indices of erectile function and QOL.