Impact of introduction of sildenafil on other treatment modalities for erectile dysfunction: a study of nationwide and local hospital sales

We assess the impact of introduction of sildenafil on alprostadil injection and penile implant surgery for the treatment of erectile dysfunction (ED) at our institution and in Taiwan. The data of national sales of sildenafil, alprostadil injection and penile implant were provided by industry companies. In the meanwhile, we analyzed the users of the above-mentioned three treatments at our institution. The national sales of sildenafil grew 136% from 0.8 million tablets in 1999 to 1.6 million tablets in 2002, while those of alprostadil injection dropped 33% after the marketing of sildenafil and of penile implant dropped 40% after the marketing of alprostadil injection and sildenafil. The market share of drugstores for sildenafil rose from 41% in 1999 to 72% in 2002. The trend of sales of sildenafil at our institution was similar to that of national sales from hospitals. Mean age of the sildenafil new users was becoming younger in the past 4 y (P<0.001). Of the new users of alprostadil injection and the recipients of penile implant, the commonest age group shifted from the range of 60-69 y before the launch of sildenafil to that of over 70 y after (P<0.05). In conclusion, the introduction of sildenafil has prompted more men as well as younger men with ED to seek treatment. Part of the roles of alprostadil injection and penile implants in this field are substituted by sildenafil and the commonest age group of their users becomes older than before.     

Sildenafil citrate vs intracavernous alprostadil for patients with arteriogenic erectile dysfunction: a randomised placebo controlled study

We compared the effectiveness of sildenafil citrate and alprostadil in improving arterial penile inflow (peak systolic velocity (PSV)) and penile rigidity in 55 patients with erectile dysfunction caused by atherosclerosis. A total of 35 patients with pure vasculogenic impotency were randomly assigned to alprostadil (Av group; n=11), sildenafil (Sv group; n=12), or placebo (P group; n=12), and 20 patients with nonvasculogenic impotency were randomly assigned to alprostadil (A group; n=10) or Sildenafil (S group; n=10): Av and A used alprostadil injection (capable of giving a full erection) once a week for 1 month, Sv and S took daily oral sildenafil (25 mg) for 1 month, and P took daily oral placebo for one month. The PSV was measured with Duplex sonography and penile rigidity was assessed using the IIEF-15 questionnaire, both of which were administered before and after treatment. Although both treatments improved penile rigidity, they increased PSV only in the Av and Sv groups. Our results suggest that alprostadil and oral therapy should be the starting therapy in men with vasculogenic impotency, whereas alprostadil should be avoided as the first-line approach in men with nonvasculogenic impotency.     

Is sildenafil failure in men after radical retropubic prostatectomy (RRP) due to arterial disease? Penile duplex Doppler findings in 174 men after RRP

Sildenafil is frequently the first-line treatment for post-radical retropubic prostatectomy (RRP) erectile dysfunction (ED) with maximum treatment satisfaction rates of 43%-80%. The etiology of erectile dysfunction after RRP has been attributed to psychogenic, vascular, veno- occlusive or nerve injury causes. The purpose of this study was to gain insight into the penile duplex Doppler arterial parameters in men with ED after RRP who failed sildenafil. The purpose was to assess whether sildenafil failure after RRP is associated with underlying corporal arterial disease. A total of 174 consecutive men presenting with sildenafil refractory ED after nerve-sparing RRP underwent color duplex penile Doppler evaluation with vasoactive injection. Mean age was 59.6 y and mean time from surgery was 11.6 months. Some 81% (141/174) of the men had no pre-operative ED (PED). Significant differences in penile duplex Doppler parameters for arterial disease were seen between men with and without PED. In men without PED, 19% (27/141) manifested arterial insufficiency. However, in men with PED, 50% (16/33) demonstrated arterial disease. Nerve sparing status did not affect the presence of arterial disease. Sildenafil refractory erectile dysfunction after RRP in men without PED is not predominantly associated with penile Doppler parameters consistent with arterial insufficiency.     

SILDENAFIL CITRATE AFTER RADICAL RETROPUBIC PROSTATECTOMY

PURPOSE: Erectile dysfunction continues to be a significant problem for men after radical retropubic prostatectomy despite nerve sparing techniques. Sildenafil citrate (Viagra) has proved effective for erectile dysfunction in many men. We determine the efficacy of sildenafil in men with erectile dysfunction after radical retropubic prostatectomy and examine variables that may impact the response to treatment. MATERIALS AND METHODS: A total of 84 men were prescribed sildenafil after radical retropubic prostatectomy and asked to complete a series of questionnaires, including the International Index of Erectile Function (IIEF), on erectile function before and after sildenafil administration. The importance of factors, such as patient age, time since surgery, degree of cavernous nerve sparing, preoperative prostate specific antigen, Gleason score, clinical and pathological stage, and baseline postoperative erectile function, was examined. RESULTS: Of the 84 patients 45 (53%) had improved erections and 34 (40%) had improved ability for intercourse while taking sildenafil. Mean IIEF score for the erectile function domain increased from 9 to 14 (p <0.001). Orgasmic function (p = 0.004) and intercourse satisfaction (p = 0.009) also significantly improved. The degree of nerve sparing and baseline postoperative erectile dysfunction had a significant impact on the ability of sildenafil to improve erectile function (p = 0.010 and p <0.001, respectively) and total IIEF questionnaire responses (p = 0.031 and p <0.001, respectively). Age and pathological stage also appeared to have a significant effect. CONCLUSIONS: Sildenafil improved erectile function and the ability to have intercourse in more than half of men after radical retropubic prostatectomy. Baseline postoperative erectile function, which is dependent on the degree of nerve sparing technique, significantly impacts the likelihood that patients will respond to sildenafil.     

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.     

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.     

Oral and injectable medications for the treatment of erectile dysfunction

The treatment of erectile dysfunction has changed dramatically over the past two decades. The introduction of the oral agent sildenafil 2 years ago has revolutionized the treatment of men with compromised erections and has met with expected success and low morbidity. Sildenafil is effective in most men with erectile dysfunction in the general population and in select populations, such as men with spinal cord injury, diabetes mellitus, and patients who have had nerve-sparing radical prostatectomy. It is safe in the general population as well as in many men with cardiac disease. Other newer medications are in trial and may soon be available to supplement treatment with sildenafil. Oral phentolamine, apomorphine, newer phosphodiesterase type-5 inhibitors, and topical agents are currently in phase 3 trials. These agents, in addition to newer intraurethral and indictable agents, may assist men with erectile dysfunction and rescue those in whom sildenafil is ineffective or in whom untoward side effects of sildenafil reduce its effectiveness. The 21st century will witness many additional agents designed for specific patients with specific conditions causing erectile dysfunction. We can expect these oral agents, assisted by topical and injectable agents, to successfully restore erectile function in the majority of men suffering from erectile dysfunction.     

The efficacy of sildenafil citrate following radiation therapy for prostate cancer: temporal considerations

PURPOSE: Erectile dysfunction is a recognized complication of radiation therapy for prostate cancer. Sildenafil citrate is a well-known management strategy for erectile dysfunction that has been found to be efficacious across a wide spectrum of comorbidities, including post-radiation erectile dysfunction. We defined the efficacy of sildenafil citrate in patients with erectile dysfunction following radiation therapy for prostate cancer and assessed the impact of the interval after radiation on the success of this therapy. MATERIALS AND METHODS: Baseline and followup data on 110 patients presenting with erectile dysfunction secondary to radiation for prostate cancer was obtained. A total of 68 patients underwent 3-dimensional conformal external beam irradiation (CRT), while 42 underwent brachytherapy (BT) without androgen deprivation. All patients were considered to have erectile dysfunction after radiotherapy, as assessed by the International Index of Erectile Function (IIEF), and they were prescribed sildenafil citrate. Mean time +/- SD between the completion of radiation therapy and the initiation of sildenafil was 8 +/- 4 months. The response to sildenafil was assessed using the IIEF questionnaire. Within and between group comparisons were done for 3 time points, that is less than 12, 13 to 24 and 25 to 36 months following the completion of radiation therapy. RESULTS: The respective response rates in men who underwent BT/CRT at the 3 time points of less than 12, 13 to 24 and 25 to 36 months was 76%/68%, 54%/46% and 44%/38%, respectively. Mean IIEF erectile function domain scores for these 3 time points after BT/CRT was 26/23, 22/19 and 17/15, respectively. The percent of patients who achieved normalization of the IIEF erectile function domain at the 3 time points in the BT/CRT groups was 60%/50%, 48%/42% and 26%/19%, respectively. CONCLUSIONS: Sildenafil citrate improves erectile function in men in whom erectile dysfunction develops following radiation therapy for prostate cancer. There is a clear time dependence for the response to this therapy with a stepwise decrease in all end points examined serially in a 3-year period.     

The synergism of penile venous surgery and oral sildenafil in treating patients with erectile dysfunction

A possible synergistic effect between penile venous surgery and oral sildenafil was inadvertently found in treating patients with erectile dysfunction in our clinic. We therefore sought to elucidate the possible synergic effect between venous surgery and sildenafil through studying patients who were non-responders preoperatively. From July 1998 to July 2003, 128 patients were diagnosed with veno-occlusive dysfunction. Subsequently, 65 of them underwent penile venous surgery and were assigned to the surgical treatment group. The remaining 63 men were assigned to the control group, and were subject to a simple re-exposure of oral sildenafil. All patients were evaluated with the international index of erectile function (IIEF-5) scoring. Sildenafil (12.5-100 mg) was prescribed postoperatively to all surgical patients as venous surgery alone was unsatisfactory and similarly, 100 mg preparation was prescribed for patients in the control group. The IIEF-5 scoring in the control group changed from a preoperative mean IIEF-5 score of 9.4 +/- 3.9 to 10.7 +/- 3.5 postoperatively. In surgical patients, however, the mean preoperative IIEF-5 score of 9.2 +/- 5.0, which increased to 15.1 +/- 5.0 (p < 0.001) postoperatively, further increased to 20.1 +/- 5.4 (p < 0.0001) after the addition of sildenafil. Although there was no significant difference between the two groups characteristics, there was a statistically significant difference between treatment results (p < 0.001). Overall, 61 men (93.8%) reported a positive response to sildenafil after venous stripping surgery. In contrast, only eight patients (12.7%) felt a beneficial response in the control group (p < 0.001). Forty-one of 65 patients had scores of > or =22, and 19 of these had a score of 25. No response was found in three (4.6%), and a decrease of 7 was seen in one (1.5%). In summary, patients in whom sildenafil was not effective preoperatively can become excellent responders after careful penile venous surgery. It appears that together, oral sildenafil and penile venous surgery may provide an encouraging solution to impotent patients with veno-occlusive dysfunction who are non-responders to sildenafil.     

Sildenafil does not improve sexual function in men without erectile dysfunction but does reduce the postorgasmic refractory time

Sildenafil is one of two oral drugs approved for first-line treatment of erectile dysfunction (ED). Anecdotally, some young healthy men who wish to enhance their sexual performance are requesting or abusing sildenafil. In this randomized double-blind, placebo-controlled clinical study, we investigated the effect of sildenafil in young men without ED. A total of 60 young healthy men age 20-40 y with no reported ED were enrolled for this single-dose home-use study. Subjects had used no medication in the 6 months prior to the study. All had been engaged in a stable relationship for at least 3 months. After completing the IIEF-5 questionnaire, patients were randomized in a double-blind fashion to receive either one 25 mg tablet of sildenafil (group 1) taken prior to intercourse, or an identical placebo tablet (group 2). All subjects completed a questionnaire relating to their erectile quality. There were no differences between the two groups in the reported improvement of erection quality, 12/30 sildenafil vs 10/30 placebo (Fisher's test, P=0.79). Sildenafil caused a significant reduction of the postejaculatory refractory time (12/30 vs 4/30) (chi(2) test, P=0.04). Sildenafil does not improve erections in young healthy men. Sildenafil should not be given to young healthy men to improve their erections and patients should be advised against recreational abuse of the drug. In this limited single-dose home study, sildenafil appears to reduce the postorgasmic refractory time. Although controlled studies are needed to evaluate the efficacy of erection-enhancing drugs in premature ejaculation, it is possible that sildenafil might be useful for this indication.     

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.     

Clinical efficacy of sildenafil in patients on chronic dialysis

PURPOSE: We evaluate the clinical efficacy of sildenafil citrate for patients who are on chronic dialysis and who have concomitant erectile dysfunction. MATERIALS AND METHODS: A total of 35 men (mean age 60.7 years) on dialysis and with erectile dysfunction of various etiologies were administered 25 to 100 mg sildenafil for at least 6 months. The International Index of Erectile Function questionnaire (IIEF), a global assessment question and partner satisfaction question were used to evaluate sildenafil efficacy. Patients also reported any adverse events that occurred during treatment. RESULTS: Treatment was effective for 28 of the 35 (80%) patients according to the results of the IIEF and global assessment questions. Partner satisfaction correlated with the IIEF overall response (0.79) and global assessment question results (0.86). No correlation was found between sildenafil failure and patient age, the etiology of erectile dysfunction, duration of erectile dysfunction, prior treatments, testosterone and prolactin blood levels, and the duration and etiology of renal failure. Of the 35 patients sildenafil was stopped due to intolerable headaches in 3 and because of lack of efficacy in 7. CONCLUSIONS: Sildenafil is an effective and safe treatment for erectile dysfunction in most patients on chronic dialysis.     

Clinical efficacy and safety of sildenafil citrate (Viagra) in a multi-racial population in Singapore: A retrospective study of 1520 patients

BACKGROUND: Sildenafil citrate (Viagra), a selective inhibitor of cGMP-specific phosphodiesterase type-5, has been used as an oral therapeutic drug for erectile dysfunction. The present paper is a clinical study of the success rate and side-effects of the use of sildenafil in a multi-racial population in Singapore. METHODS: From April 1999 to May 2000, 1520 patients were given sildenafil citrate. Of these, 912 patients (mean age, 54.6 years; age range, 22-99 years) were followed up and evaluated for clinical efficacy and safety of the drug. The mean duration of erectile dysfunction (ED) and follow-up periods were 31.5 and 3.0 months, respectively. RESULTS: Satisfactory erections assessed by single global efficacy question (GEQ) occurred in 83% of patients, major side-effects in the form of flushing (3.48%), headache (1.97%), blurred vision (1.25%), giddiness (1.18%), warmth (1.11%) and others (4.92%) were recorded in 127 patients (13.9%). Racially, Chinese men with ED had higher efficacy (85.7%), compared to Indian men (74.2%) and Malay men (72.8%). With respect to comorbid profiles, an efficacy of 77.8% (n = 271), 83.9% (n = 292), 86.4% (n = 44) and 83.3% (n = 199) was recorded in diabetic, hypertensive, ischemic heart disease patients and in benign prostatic hyperplasia patients, respectively. Patients who smoked (n = 135) and drank alcohol (n = 118) showed an efficacy of 80%. Baseline hormonal profiles of luteinizing hormone, follicle stimulating hormone, testosterone and prolactin did not affect the success rates of sildenafil citrate. Many patients had earlier received other forms of treatment (medicated urethral suppository for erection (MUSE; 84.9%); vacuum devices (86.8%), traditional medicines (100%) and other oral medications (89.2%)), but this did not influence the success rate of sildenafil citrate. But patients previously treated with prostaglandin-E intracavernosal injections were less successful on sildenafil citrate (77.3%). In the total cohort, 50 mg sildenafil citrate was an effective dose in 49% of patients and 46.5% patients needed 100 mg sildenafil citrate, while 4.1% of the total cohort needed only 25 mg sildenafil citrate. CONCLUSION: Oral sildenafil citrate has been shown to be an effective, safe and well tolerated drug in Singaporean men with ED, as in men from other parts of the world.     

磷酸二酯酶5抑制剂治疗勃起功能障碍的疗效和安全性比较

磷酸二酯酶 5 (PDE 5 )抑制剂西地那非的问世使男性勃起功能障碍 (ED)的治疗手段发生了根本性的改变。1998年以来有 10 0多个国家的 2 0 0 0多万患者使用了西地那非 ,患者的死亡率与总体人群的死亡率差异无显著性。西地那非治疗ED平均有效率达 80 %以上 ,成为治疗ED的首选手段。随着新的PDE 5抑制剂伐地那非和泰地那非在国外先后进入临床使用 ,药物治疗ED有了更多的选择。本文通过比较 3种PDE 5抑制剂的药效学、药动学及不良反应以评价其疗效和安全性。     

Nonarteritic ischaemic optic neuropathy (NAION) after 36 h of intake of sildenafil citrate: first Egyptian case

Sildenafil citrate is a selective phosphodiesterase 5 (PDE-5) inhibitor and partial phosphodiesterase 6 inhibitor prescribed for erectile dysfunction. Post-marketing case reports of nonarteritic anterior ischaemic optic neuropathy (NAION) over the past few years suggest a potential link with PDE-5 inhibitors. We report a case of a 48-year-old male patient who had acute vision loss 36 h after the intake of 50 mg sildenafil citrate. NAION occurred at a period of minimal blood level of sildenafil citrate. So, erectile dysfunction drugs must be strongly considered with NAION even though their users may have neither predisposing nor precipitating factors for NAION and even if occurring at a time of minimal blood level of these drugs.     

Sildenafil response is influenced by the G protein beta 3 subunit GNB3 C825T polymorphism: a pilot study

PURPOSE: Sildenafil is the oral phosphodiesterase-5 inhibitor that revolutionized treatment for erectile dysfunction. We investigated a potential association of the G protein beta 3 subunit (GNB3) C825T polymorphism, a determinant of intracellular signal transduction, with the drug response to sildenafil in patients with erectile dysfunction. MATERIALS AND METHODS: In 113 men with erectile dysfunction and 111 healthy male controls genotype status of the GNB3 C825T polymorphism was determined by polymerase chain reaction and restriction analysis. Patients with erectile dysfunction received sildenafil at a dose of 25 to 100 mg. according to the individual erectile response. Drug response was measured by interviewing the patient according to the erection scale of 0 to 5. RESULTS: The GNB3 genotype distribution of patients with erectile dysfunction exactly matched that of healthy controls. Analysis of the response to sildenafil revealed a significant association of C825T allele status with the erectile response to sildenafil. In the group with TT genotype we observed a 90.9% response but only a 50.9% and 48.9% response in patients with the CC and TC genotype, respectively. The odds ratio for a positive erectile response was 10.0 (95% CI 1.2 to 81.1) for patients with the TT versus the TC/CC genotype (p = 0.01). CONCLUSIONS: The response to sildenafil is significantly associated with GNB3 C825T genotype status in patients with erectile dysfunction.     

Effect of sildenafil citrate on post-radical prostatectomy erectile dysfunction

PURPOSE: We assess the effect of sildenafil in a subgroup of patients after prostatectomy with erectile dysfunction and determine whether nerve preservation improves sildenafil response in this subgroup. MATERIALS AND METHODS: Between April 1998 and January 1999, 53 patients who had undergone radical retropubic prostatectomy and were prescribed oral sildenafil were surveyed using a confidential mail questionnaire. Of the patients 21 underwent bilateral and 15 unilateral neurovascular bundle sparing procedures, while in 17 a nonnerve sparing procedure was performed. All patients received 25 to 100 mg. sildenafil in a flexible dose escalation manner. Response, satisfaction and side effects were assessed using a modified, self-administered International Index of Erectile Function questionnaire. Response was defined as erection sufficient for intercourse. Preoperative and postoperative/pretreatment erectile functions were assessed for baseline comparison in each patient, and partner overall satisfaction with sildenafil was measured. Statistical data analysis was performed using analysis of variance and Newman-Keuls multiple comparison tests. RESULTS: Of the 21 patients who underwent a bilateral nerve sparing procedure 15 had a positive response. Of the 15 patients who had undergone a unilateral nerve sparing procedure 12 had a positive response, and only 1 of the 17 patients who had undergone a nonnerve sparing procedure responded to sildenafil. The most commonly reported adverse events of all causes were headaches (21%), flushing (8.3%), visual disturbance (6.3%) and nasal congestion (6.3%). CONCLUSIONS: Sildenafil is an equally effective treatment for erectile dysfunction after bilateral and unilateral nerve sparing procedures, and patient response to sildenafil is confirmed by the partners. However, patients who undergo nonnerve sparing procedures do not respond satisfactorily to sildenafil.     

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

Aim： To determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography. Methods： A total of 69 erectile dysfunction （ED） patients aged 22-79 years were enrolled into the present study. Thirty-eight （55.1%） men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A com- bination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 ug prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity （PSV）, resistance index （RI）, end diastolic velocity （EDV） and cavernosa artery diameter （CD） were measured and the results between sildenafil nonresponders and responders were compared. Results： No statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders （P 〈 0.05）. Among patients with adequate PSV （〉 30 cm/s） and abnormal EDV （〉 5 cm/s）, individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group （35.3% vs. 72.2%, P 〈 0.05）. Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response （P 〈 0.05）. Conclusion： Sildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.