New treatments for erectile dysfunction

1. Download : Download full-size image

Erectile dysfunction (ED) is an increasingly common problem, affecting up to 30 million American men. This largely results from increased risk factors and an aging population. ED is now also recognized as a marker for cardiovascular disease. The ED patient should be thoroughly evaluated for coexisting vascular disease. The pathophysiology of ED is becoming better understood, largely as a result of the development of new therapies. Once the underlying processes are known, more selective targeting of these will lead to novel “designer drugs.”     

New treatments for erectile dysfunction

Erectile dysfunction (ED) is an increasingly common problem, affecting up to 30 million American men. This largely results from increased risk factors and an aging population. ED is now also recognized as a marker for cardiovascular disease. The ED patient should be thoroughly evaluated for coexisting vascular disease. The pathophysiology of ED is becoming better understood, largely as a result of the development of new therapies. Once the underlying processes are known, more selective targeting of these will lead to novel "designer drugs."     

Effect of niacin on erectile function in men suffering erectile dysfunction and dyslipidemia

IntroductionDyslipidemia is closely related to erectile dysfunction (ED). Evidence has shown that the lipid‐lowering agent, 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase inhibitor (statins), can improve erectile function. However, information about the potential role of another class of lipid‐lowering agent, niacin, is unknown.AimTo assess the effect of niacin alone on erectile function in patients suffering from both ED and dyslipidemia.MethodsA single center prospective randomized placebo‐controlled parallel‐group trial was conducted. One hundred sixty male patients with ED and dyslipidemia were randomized in a one‐to‐one ratio to receive up to 1,500 mg oral niacin daily or placebo for 12 weeks.Main Outcome MeasuresThe primary outcome measure was the improvement in erectile function as assessed by question 3 and question 4 of the International Index of Erectile Function (IIEF Q3 and Q4). Secondary outcome measurements included the total IIEF score, IIEF‐erectile function domain, and Sexual Health Inventory for Men (SHIM) score.ResultsFrom the overall analysis, the niacin group showed a significant increase in both IIEF‐Q3 scores (0.53 ± 1.18, P < 0.001) and IIEF‐Q4 scores (0.35 ± 1.17, P = 0.013) compared with baseline values. The placebo group also showed a significant increase in IIEF‐Q3 scores (0.30 ± 1.16, P = 0.040) but not IIEF‐Q4 scores (0.24 ± 1.13, P = 0.084). However, when patients were stratified according to the baseline severity of ED, the patients with moderate and severe ED who received niacin showed a significant improvement in IIEF‐Q3 scores (0.56 ± 0.96 [P = 0.037] and 1.03 ± 1.20 [P < 0.001], respectively) and IIEF‐Q4 scores (0.56 ± 1.03 [P = 0.048] and 0.84 ± 1.05 [P < 0.001], respectively] compared with baseline values, but not for the placebo group. The improvement in IIEF‐EF domain score for severe and moderate ED patients in the niacin group were 5.28 ± 5.94 (P < 0.001) and 3.31 ± 4.54 (P = 0.014) and in the placebo group were 2.65 ± 5.63 (P < 0.041) and 2.74 ± 5.59 (P = 0.027), respectively. There was no significant improvement in erectile function for patients with mild and mild‐to‐moderate ED for both groups. For patients not receiving statins treatment, there was a significant improvement in IIEF‐Q3 scores (0.47 ± 1.16 [P = 0.004]) for the niacin group, but not for the placebo group.ConclusionsNiacin alone can improve the erectile function in patients suffering from moderate to severe ED and dyslipidemia. Ng C‐F, Lee C‐P, Ho AL, and Lee VWY. Effect of niacin on erectile function in men suffering erectile dysfunction and dyslipidemia. J Sex Med 2011;8:2883–2893.     

Clinical diagnostic approach to erectile dysfunction

Erectile dysfunction (ED) has been defined by the National Institutes of Health (NIH) as the inability to achieve and/or maintain an erection for a satisfactory sexual intercourse. Data on ED epidemiology estimate a prevalence of 12-52%; the prevalence in Italy is 12.8%. ED is a symptom, sometimes the first, of numerous internal diseases. ED can mark the point where the evaluation and prevention of illnesses (diabetes, arterial hypertension, atherosclerosis) hitherto unknown by the patient can begin. The andrologist's task is to identify the disorder underlying ED and to plan the appropriate diagnostic work-up.     

糖尿病勃起功能障碍研究进展

阴茎勃起功能障碍是糖尿病常见的并发症,其发生与多种病理生理机制相关,如糖基化终末产物、氧自由基、NO合成障碍、内皮素及其受体、上调的RhoA/Rho激酶途径、神经病变等。治疗较为困难且需要多种模式,如口服药物、阴茎内药物注射、尿道内栓剂、真空勃起装置、阴茎内假体等。     

Sexual function and satisfaction in heterosexual couples when men are administered sildenafil citrate (Viagra) for erectile dysfunction: a multicentre, randomised, double-blind, placebo-controlled trial

OBJECTIVE: To investigate the effect of improvement in erectile dysfunction (ED) on sexual function and satisfaction measures in heterosexual couples in which the woman reports that sexual intercourse is unsatisfactory at least half of the time. DESIGN: Multicentre, double-blind, placebo-controlled study. SETTING: Outpatient medical clinics. POPULATION: Hundred and eighty men with ED and their female partners in whom sexual intercourse was satisfactory about half the time or less (score of < or =3 on the Female Partner of ED Subject Questionnaire question 3 [FePEDS Q3]). METHODS: Men were randomised to flexible-dose sildenafil (25, 50, and 100 mg) or placebo as needed for 12 weeks. MAIN OUTCOME MEASURES: Primary: FePEDS Q3 ('Over the past four weeks, when you had sexual intercourse, how often was it satisfactory for you?') scored as 0 (no sexual activity) and 1 (almost never or never) to 5 (almost always or always). Secondary, partners: Sexual Function Questionnaire, Female Sexual Function Index (FSFI), and ED Inventory of Treatment Satisfaction (EDITS) partner version (EDITS-Partner). Secondary, men: International Index of Erectile Function (IIEF), General Efficacy Questions, event log data, Self-Esteem And Relationship questionnaire, and EDITS. Secondary, partners and men: Dyadic Adjustment Scale. RESULTS: The intention-to-treat population included 85 sildenafil recipients (mean age 59 +/- 12 years) and 91 placebo recipients (mean age 57 +/- 11 years). Most partners (aged 20-79 years; mean, 54 years) were postmenopausal. Sildenafil compared with placebo couples had greater improvement in the primary outcome (FePEDS Q3 [P < 0.0001]) and in sexual function, intercourse success rates, and secondary sexual satisfaction measures (FSFI satisfaction domain [P < 0.0001] and IIEF satisfaction domains [P < 0.001]) and had higher treatment satisfaction (EDITS and EDITS-Partner; P < 0.0001). Several predictors of improvement were identified, and improvement in one member of the couple correlated positively with improvement in the other member. CONCLUSIONS: The interdependence of sexual function and sexual satisfaction measures between members of couples consisting of men with ED and sexually healthy women reporting infrequent satisfactory sexual intercourse underscores the importance of including partners in ED treatment discussions.     

Topical and oral agents for erectile dysfunction.

Innovative research in the past 2 decades has shown that the hemodynamics of penile erection involve arterial dilation, sinusoidal expansion, and venous compression. Relaxation of the intracorporeal smooth muscles (trabecular and arteriolar) seems to be the final common pathway that leads to the above events. Neuropharmacologic studies have also established nitric oxide as the principal neurotransmitter for penile erection and confirmed the importance of cyclic adenosine monophosphate and cyclic guanosine monophosphate systems in penile smooth muscle relaxation. Recent years have also witnessed dramatic changes in the therapy of erectile dysfunction. The penile prosthesis, a gold standard of therapy of the 1970s, was replaced in the 1980s by the intracavernous injection and the vacuum constriction device. In the 1990s, two revolutionary concepts in erectile dysfunction therapy were added: transurethral alprostadil and oral sildenafil. However, the tremendous publicity surrounding the recent introduction of sildenafil has also created socioeconomic and ethical dilemmas, especially with regard to insurance coverage and government regulation. Medically, many problems also surfaced when large numbers of erectile dysfunction patients overwhelmed primary care physicians who were unfamiliar with the diagnosis and treatment of erectile dysfunction. This article reviews the advances in penile physiology and the clinical usefulness of topical and oral agents. In addition, a patients' goal-directed approach to the diagnosis and treatment of erectile dysfunction is presented.     

Vardenafil restores erectile function to normal range in men with erectile dysfunction

IntroductionThe ability of oral phosphodiesterase type 5 (PDE5) inhibitor therapy to restore erectile function to normal is an important attribute to men with erectile dysfunction (ED).AimTo assess the ability of vardenafil to restore normal erectile function in men with general ED.MethodsIn two fixed‐dose, parallel‐group, double‐blind, placebo‐controlled, pivotal studies, patients received vardenafil (5, 10, or 20 mg) or placebo for 12/26 weeks.Main Outcome MeasureIn this retrospective analysis, the percentage of patients “returning to normal” erectile function at week 12 (as defined by scores ≥26 on erectile function domain of International Index of Erectile Function [IIEF‐EF]) was determined, with further stratification by baseline ED severity, etiology, age, and duration of ED.ResultsVardenafil 5, 10, and 20 mg returned 32%, 43%, and 49% of patients, respectively, to normal erectile function after 12 weeks, compared with 10% of patients receiving placebo (P < 0.0001). Return to normal IIEF‐EF domain scores was noted irrespective of severity, etiology, age, and duration of ED, and was observed even in challenging‐to‐treat subgroups. With vardenafil 20 mg, 39% of men with severe ED at baseline, 45–49% of men with ED of mixed or organic etiology, 35% of men aged ≥65 years, and 43% of men with ED of ≥3 years of duration returned to normal erectile function at week 12. Mean per‐patient SEP3 (question 3 on the Sexual Encounter Profile) success rates in patients achieving IIEF‐EF domain scores ≥26 ranged from 87% to 95%.ConclusionVardenafil improves the IIEF‐EF domain score to the normal range in a substantial proportion of men with ED. Padma‐Nathan H, Montorsi F, Giuliano F, Meuleman E, Auerbach S, Eardley I, McCullough A, Homering M, and Segerson T for the North American and European Vardenafil Study Group. Vardenafil restores erectile function to normal range in men with erectile dysfunction. J Sex Med 2007;4:152–161.