The efficacy of sildenafil citrate (Viagra) in clinical populations: an update

App-based Therapy of Erectile Dysfunction Using a Digital Health Application (EDDIG Study): A Randomized, Single-blind, Controlled Trial

BACKGROUND AND OBJECTIVE

While international guidelines advocate for a multifaceted approach to treating erectile dysfunction (ED) involving physical activities, psychological support, and education, structured programs are infrequent. To address this gap, an app-based therapy was developed, offering a systematic approach. This randomized, single-blind controlled trial aimed to assess the effectiveness of an app-based therapeutic in improving ED.

METHODS

A total of 241 patients (49.74, standard deviation 12.73 yr) with ED (International Index of Erectile Function [IIEF]-5 <22) were randomized to the 12-wk app-based therapy (treatment group [TG], n = 122) or a waiting list for the app with continuation of their current management protocol (control group [CG], n = 119). Patients on long-term medication for ED were included, but subsequent exclusion occurred for those starting new medication. Coprimary endpoints were improvements from baseline to 12 wk in erectile function (IIEF-5), disease-related quality of life (QOL-Med-15), and patient activation (Patient Activation Measure [PAM-13]).

KEY FINDINGS AND LIMITATIONS

Erectile function (IIEF-5) improved by 4.5 points in the TG versus 0.2 points in the CG (p < 0.0001, 95% confidence interval [CI] 3.4-5.0) group. Quality of life (QOL-Med) improved by 20.5 points in the TG versus -0.0 points in the CG (p < 0.0001, 95% CI 19.2-26.0) group. Patient activation (PAM-13) improved by 11.2 points in the TG versus 0.6 points in the CG (p < 0.0001, 95% CI 9.1-13.6) group. Phosphodiesterase type 5 inhibitor intake had no influence on all observed treatment effects.

CONCLUSIONS AND CLINICAL IMPLICATIONS

App-based therapy of patients with ED provided a significant, clinically meaningful improvement. Quality of life and patient activation were also enhanced significantly. This program has the potential to change clinical practice in the treatment of ED.

PATIENT SUMMARY

A therapy app improved sexual function and overall well-being for men experiencing erectile dysfunction, leading to better quality of life.

Advancements in Phosphodiesterase 5 Inhibitors: Unveiling Present and Future Perspectives

Phosphodiesterase 5 (PDE5) inhibitors presented themselves as important players in the nitric oxide/cGMP pathway, thus exerting a profound impact on various physiological and pathological processes. Beyond their well-known efficacy in treating male erectile dysfunction (ED) and pulmonary arterial hypertension (PAH), a plethora of studies have unveiled their significance in the treatment of a myriad of other diseases, including cognitive functions, heart failure, multiple drug resistance in cancer therapy, immune diseases, systemic sclerosis and others. This comprehensive review aims to provide an updated assessment of the crucial role played by PDE5 inhibitors (PDE5-Is) as disease-modifying agents taking their limiting side effects into consideration. From a medicinal chemistry and drug discovery perspective, the published PDE5-Is over the last 10 years and their binding characteristics are systemically discussed, and advancement in properties is exposed. A persistent challenge encountered with these agents lies in their limited isozyme selectivity; considering this obstacle, this review also highlights the breakthrough development of the recently reported PDE5 allosteric inhibitors, which exhibit an unparalleled level of selectivity that was rarely achievable by competitive inhibitors. The implications and potential impact of these novel allosteric inhibitors are meticulously explored. Additionally, the concept of multi-targeted ligands is critically evaluated in relation to PDE5-Is by inspecting the broader spectrum of their molecular interactions and effects. The objective of this review is to provide insight into the design of potent, selective PDE5-Is and an overview of their biological function, limitations, challenges, therapeutic potentials, undergoing clinical trials, future prospects and emerging uses, thus guiding upcoming endeavors in both academia and industry within this domain.

Update of the position paper on arterial hypertension and erectile dysfunction

: Sexual health is an integral part of overall health, and an active and healthy sexual life is an essential aspect of a good life quality. Cardiovascular disease and sexual health share common risk factors (arterial hypertension, diabetes mellitus, dyslipidemia, obesity, and smoking) and common mediating mechanisms (endothelial dysfunction, subclinical inflammation, and atherosclerosis). This generated a shift of thinking about the pathophysiology and subsequently the management of sexual dysfunction. The introduction of phosphodiesterase type 5 inhibitors revolutionized the management of sexual dysfunction in men. This article will focus on erectile dysfunction and its association with arterial hypertension. This update of the position paper was created by the Working Group on Sexual Dysfunction and Arterial Hypertension of the European Society of Hypertension. This working group has been very active during the last years in promoting the familiarization of hypertension specialists and related physicians with erectile dysfunction, through numerous lectures in national and international meetings, a position paper, newsletters, guidelines, and a book specifically addressing erectile dysfunction in hypertensive patients. It was noted that erectile dysfunction precedes the development of coronary artery disease. The artery size hypothesis has been proposed as a potential explanation for this observation. This hypothesis seeks to explain the differing manifestation of the same vascular condition, based on the size of the vessels. Clinical presentations of the atherosclerotic and/or endothelium disease in the penile arteries might precede the corresponding manifestations from larger arteries. Treated hypertensive patients are more likely to have sexual dysfunction compared with untreated ones, suggesting a detrimental role of antihypertensive treatment on erectile function. The occurrence of erectile dysfunction seems to be related to undesirable effects of antihypertensive drugs on the penile tissue. Available information points toward divergent effects of antihypertensive drugs on erectile function, with diuretics and beta-blockers possessing the worst profile and angiotensin receptor blockers and nebivolol the best profile.

The Use of Vasoactive Drugs in the Treatment of Male Erectile Dysfunction: Current Concepts

It is widely accepted that disorders of the male (uro)genital tract, such as erectile dysfunction (ED) and benign diseases of the prostate (lower urinary tract symptomatology or benign prostatic hyperplasia), can be approached therapeutically by influencing the function of both the vascular and non-vascular smooth muscle of the penile erectile tissue or the transition zone/periurethral region of the prostate, respectively. As a result of the discovery of nitric oxide (NO) and cyclic guanosine monophosphate (GMP) as central mediators of penile smooth muscle relaxation, the use of drugs known to increase the local production of NO and/or elevate the intracellular level of the second messenger cyclic GMP have attracted broad attention in the treatment of ED of various etiologies. Specifically, the introduction of vasoactive drugs, including orally active inhibitors of the cyclic GMP-specific phosphodiesterase (PDE) 5, has offered great advantage in the pharmacotherapy of ED and other diseases of the genitourinary tract. These drugs have been proven efficacious with a fast on-set of action and an improved profile of side-effects. This review summarizes current strategies for the treatment of ED utilizing the application of vasoactive drugs via the oral, transurethral, topical, or self-injection route.

Intracavernous delivery of Dickkopf3 gene or peptide rescues erectile function through enhanced cavernous angiogenesis in the diabetic mouse

BACKGROUND

Severe peripheral angiopathy in patients with diabetes is a major contributing factor for low response rate to phosphodiesterase-5 inhibitors.

OBJECTIVES

To examine whether and how Dickkopf3 (DKK3), a secreted modulator of the Wnt pathway that known to be involved in endothelial cell repair and vascular progenitor cell migration, restores erectile function in diabetic mice.

METHODS

Eight-week-old C57BL/6 mice received intraperitoneal injections of streptozotocin (50 mg/kg for 5 days). Eight weeks after the diabetes was induced, the efficacy of DKK3 was determined by three independent experiments: experiment 1 (DKK3 peptide [5 μg in 20 μL PBS]); experiment 2 (DKK3 plasmid DNA with electroporation [10, 40, or 100 μg in 20 μL PBS, respectively]); and experiment 3 (DKK3 adenovirus [1 × 10⁷ , 1 × 10⁸ , 1 × 10⁹ virus particles per 20 μL, respectively]). Erectile function was measured by electrical stimulation of the cavernous nerve one week (for peptide) or two weeks (for genes) after treatment. The angiogenic activity of DKK3 was determined in diabetic penis in vivo and in primary cultured mouse cavernous endothelial cells (MCECs) in vitro.

RESULTS

The cavernous expression of DKK3 protein was significantly lower in the diabetic mice than in controls. DKK3 peptide or adenovirus significantly improved erectile function in diabetic mice (70% of the control values). DKK3 adenovirus profoundly restored cavernous endothelial cell and pericyte contents and increased endothelial junction proteins in diabetic mice in vivo. DKK3 peptide induced upregulation of angiogenic factors (angiopoietin-1, vascular endothelial growth factor, and basic fibroblast growth factor) and accelerated tube formation in MCECs cultivated under the high-glucose condition in vitro.

CONCLUSION

DKK3 restored cavernous vascular integrity and improved erectile function in diabetic mice. Therapeutic cavernous angiogenesis by the use of DKK3 will be a promising therapeutic strategy to treat diabetic erectile dysfunction.

Combination of stromal vascular fraction and Ad-COMP-Ang1 gene therapy improves long-term therapeutic efficacy for diabetes-induced erectile dysfunction

Men with diabetic erectile dysfunction (ED) respond poorly to the currently available oral phosphodiesterase-5 inhibitors. Therefore, functional therapies for diabetic ED are needed. Stromal vascular fraction (SVF) and the adenovirus-mediated cartilage oligomeric matrix angiopoietin-1 (Ad-COMP-Ang1) gene are known to play critical roles in penile erection. We previously reported that SVF and Ad-COMP-Ang1 have only a short-term effect in restoring erectile function. Further improvements to ED therapy are needed for long-lasting effects. In the present study, we aimed to test if the combination of SVF and Ad-COMP-Ang1 could extend the erection effect in diabetic ED. We found that the combination therapy showed a long-term effect in restoring erectile function through enhanced penile endothelial and neural cell regeneration. Combination therapy with SVF and Ad-COMP-Ang1 notably restored cavernous endothelial cell numbers, pericyte numbers, endothelial cell–cell junctions, decreased cavernous endothelial cell permeability, and promoted neural regeneration for at least 4 weeks in diabetic mice. In summary, this is an initial description of the long-term effect of combination therapy with SVF and Ad-COMP-Ang1 in restoring erectile function through a dual effect on endothelial and neural cell regeneration. Such combination therapy may have therapeutic potential for the treatment of diabetic ED.

Influence of Alcohol on Phosphodiesterase 5 inhibitors Use in Middle- to Old-Aged Men: A Comparative Study of Adverse Events

INTRODUCTION

Some previous studies reported recreational use of phosphodiesterase type 5 (PDE-5) inhibitors by ingesting the medicine with alcohol in patients with erectile dysfunction, but the rate of misuse in general population has never been researched.

AIM

To investigate the frequency of concomitant alcohol consumption with PDE-5 inhibitors in the general male population. We secondarily analyzed the influence of alcohol on PDE-5 inhibitor.

METHODS

325 men with erectile dysfunction (age 34-78) who received PDE-5 inhibitors at a single medical institution from January 2016-February 2018 were included in the study. All patients fulfilled a survey questionnaire assessing (i) average alcohol consumption amount, (ii) previous use of PDE-5 inhibitors with alcohol and purpose of concomitant alcohol use, (iii) and background knowledge about PDE-5 inhibitors' side effects.

MAIN OUTCOMES MEASURES

The main outcome measure was frequency of concomitant alcohol consumption with PDE-5 inhibitors in the general male population.

RESULTS

Overall 148 patients committed concomitant alcohol use (group 1), and 177 patients did not (group 2). No significant differences were observed between 2 groups regarding types of PDE-5 inhibitors used and underlying disease. Group 2 had significantly more patients with the correct knowledge concerning concomitant alcohol use than group 1 (24.9% vs 13.5%). Group 1 had more patients with average alcohol consumption >15 drinks/week (64.8% vs 14.1%). The reasons for concomitant alcohol use were curiosity (35.1%), enhancing sexual desire (27%) and recommendation from friends (16.9%). Group 1 showed significantly greater complications, including headache (23.6% vs 7.3%) and facial flushing (69.6% vs 12.4%), than group 2. 1 patient in group 1 experienced severe chest discomfort and underwent coronary artery angiography, but no severe obstructive lesion was observed.

CONCLUSION

45.5% of middle- to old-age men committed concomitant use of PDE-5 inhibitor with alcohol because of recreational purpose, and this alcohol abuse might lead to severe complications, including chest discomfort and dizziness. Kim JN, Oh JJ, Park DS, et al. Influence of Alcohol on Phosphodiesterase 5 inhibitors Use in Middle- to Old-Aged Men: A Comparative Study of Adverse Events. Sex Med 2019;7:425-432.

Current guideline recommendations and analysis of evidence quality on low-intensity shockwave therapy for erectile dysfunction

Erectile dysfunction (ED) is defined as the inability to attain and maintain erection of the penis sufficient to permit satisfactory sexual activity. ED most commonly affects men from 40 years of age with a clear age-associated increase in prevalence. The condition may have significant negative impact on quality of life for both the patients and their partners. Over recent years, low-intensity shockwave therapy (LIST) has gained popularity in the treatment of ED, based on the assumption that LIST application may result in neoangiogenesis and thus increased blood flow to the corpora cavernosa. The increasing usage of LIST is contrasting with current guidelines, with the EAU guideline on ED stating that LIST can be used in mild organic ED patients or poor responders to PDE5I's, but with a weak strength of recommendation. In the AUA guideline on ED, the panel makes a conditional recommendation of grade C that LIST should be considered investigational. In this review, we will briefly review practice patterns, and critically discuss the evidence based on which these guideline statements have been made.

Pharmacotherapy for erectile dysfunction in diabetic males

INTRODUCTION

Numerous studies have highlighted the intimate association between erectile dysfunction (ED) and diabetes mellitus (DM). However, the true pathogenesis of ED among diabetic men has not yet been fully discovered. The treatment of ED in diabetic patients remains an interesting area of research. The last two decades have witnessed phenomenal advances in the management of ED with the efficacy of pharmacotherapy for ED in diabetic patients encouraging, especially with introduction of innovative conservative tools for treatment.

AREAS COVERED

The aim of this review is to discuss the currently available information on ED pharmacotherapy in diabetic males and provide an expert perspective on the current treatment strategies.

EXPERT OPINION

Conservative treatment remains the initial step for the treatment of ED in diabetic patients. This kind of therapy consists of different modalities including: oral treatments, intracavernosal pharmacotherapy, and evolving modalities such as soluble guanylate cyclase activators, stem cells (SCs), and alternative treatments such as herbal treatment and transdermal/topical pharmacotherapy. However, it should be noted that the currently available pharmacotherapy is still far from ideal. One hopes to witness new drugs and technologies that may revolutionize ED treatment in the future, especially in such complex cases as DM.

Islet transplantation improved penile tissue fibrosis in a rat model of type 1 diabetes

BACKGROUND

Glycaemic control is one of the most effective strategies for the treatment of diabetes-related erectile dysfunction (DMED). Compared to conventional anti-diabetic drugs and insulin, islet transplantation is more effective in the treatment of diabetic complications. The aim of this study was to investigate the efficacy of islet transplantation for reversing advanced-stage DMED in rats and to observe its influence on corpus cavernosum fibrosis.

METHODS

Wistar rats were intraperitoneally injected with streptozotocin to establish a diabetes model. After 12 weeks, the rats were divided into 4 groups: diabetic, insulin, islet transplantation, and normal control. Following supplementation, the changes in blood glucose and weight were determined sequentially. Penile erectile function was evaluated by apomorphine experiments in the fourth week, and the penile corpus cavernosum was also collected for assessment by Masson staining, immunohistochemistry and Western blot to observe the spongy tissue and the related cellular changes at the molecular level.

RESULTS

Islet transplantation significantly ameliorated penile erectile function in advanced-stage diabetic rats. The ratio of corpus cavernosum smooth muscle cells to fibroblasts and the expression level of α-SMA in the islet transplantation group were significantly higher than those in the diabetic and insulin groups. In addition, the expression levels of TGF-β1, p-Samd2, and connective tissue growth factor (CTGF) in the islet transplantation and insulin groups were much lower than those in the diabetic group, while those in the islet transplantation group were significantly lower than those in the insulin group.

CONCLUSIONS

Our findings strongly suggest that islet transplantation can promote the regeneration of smooth muscle cells and ameliorate corpus cavernosum fibrosis to restore its normal structure in advanced-stage diabetic rats. The possible mechanism of ameliorating corpus cavernosum fibrosis by islet transplantation may be associated with improvement of the hyperglycaemic status in diabetic rats, thereby inhibiting the TGF-β1/Samd2/CTGF pathway.

Quality of erections by age group in men with erectile dysfunction

AIMS

The aim of this study was to assess erection quality with sildenafil vs placebo and adverse events (AEs) according to age (≤45, 46-55 and ≥56 years) in 997 men with erectile dysfunction (ED) using pooled data from four randomized, double-blind, placebo-controlled, flexible-dose trials.

METHODS

The trials included 6- to 10-week treatment periods. The starting sildenafil dose was 50 mg, taken ~1 hour before sexual activity but not more than once daily, with subsequent adjustment to 100 or 25 mg based on efficacy and safety. Exclusion criteria included blood pressure <90/50 or >170/110 mmHg, taking nitrate therapy or nitric oxide donors, severe cardiac failure/unstable angina or recent stroke or myocardial infarction. Changes from baseline in Quality of Erection Questionnaire (QEQ), International Index of Erectile Function (IIEF) and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) scores were analysed.

RESULTS

Improvements in QEQ scores with sildenafil vs placebo were significant (P<.0001) for the overall sample (33.7 sildenafil; 8.1 placebo) and each age group (≤45 years: 38.5 sildenafil, 13.9 placebo; 46-55 years: 34.9 sildenafil, 5.8 placebo; ≥56 years: 26.9 sildenafil, 4.9 placebo). IIEF Erectile Function domain (P<.0001), question 3 (achieving erection; P<.003), and question 4 (maintaining erection; P<.001) scores also improved significantly for the overall sample and each age group. Treatment satisfaction was significantly greater (P<.0001) with sildenafil vs placebo for the overall sample and each age group. The most common AEs with sildenafil were headache, flushing and nasal congestion in all age groups.

CONCLUSIONS

Sildenafil significantly improved erection quality across all age groups of men with ED. Efficacy improvements with sildenafil were consistent with the QEQ, IIEF, and EDITS. AEs were comparable across age groups. ClinicalTrials.gov ID: NCT00159900, NCT00147628, NCT00301262, NCT00343200.

Efficacy and Safety of Sildenafil by Age in Men With Erectile Dysfunction

INTRODUCTION

Sildenafil, an oral phosphodiesterase type 5 inhibitor, has been extensively investigated for the treatment of erectile dysfunction in randomized controlled trials.

AIM

To assess the efficacy and safety of sildenafil vs placebo according to age subgroups (<65, 65-74, and ≥75 years) in 11,364 men with erectile dysfunction using pooled data from 48 randomized, double-blinded, placebo-controlled, parallel-group, flexible-dose trials.

METHODS

Most trials had a 12-week treatment duration. The starting sildenafil dose was 50 mg, taken 1 hour before sexual activity, with subsequent adjustment to 100 or 25 mg based on efficacy and safety. Men taking nitrate therapy or nitric oxide donors and men with severe cardiac failure, unstable angina, or recent stroke or myocardial infarction were excluded. Efficacy analyses included all subjects with baseline and at least one postrandomization evaluation. Safety analyses included subjects who received study medication.

MAIN OUTCOME MEASURES

The International Index of Erectile Function and a global assessment question ("Did the treatment improve your erections?").

RESULTS

Mean International Index of Erectile Function scores for question 3 (frequency of penetration), question 4 (maintenance of erections after penetration), and the erectile function domain were statistically significantly improved with sildenafil vs placebo for each age subgroup; orgasmic function, intercourse satisfaction, sexual desire, and overall satisfaction domain scores also were statistically significantly improved with sildenafil vs placebo. The percentage of men reporting improved erections on the global assessment question was statistically significantly higher with sildenafil vs placebo for all age subgroups; the percentage with sildenafil tended to decrease with increasing age (<65 years, 80%; 65-74 years, 69%; ≥75 years, 59%). The most common adverse events with sildenafil were headache and flushing in each age subgroup.

CONCLUSION

Sildenafil is an effective and well-tolerated treatment for erectile dysfunction regardless of patient age, including men at least 75 years old.

Clinical and preclinical treatment of urologic diseases with phosphodiesterase isoenzymes 5 inhibitors: an update

Phosphodiesterase isoenzymes 5 inhibitors (PDE5-Is) are the first-line therapy for erectile dysfunction (ED). The constant discoveries of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) cell-signaling pathway for smooth muscle (SM) control in other urogenital tracts (UGTs) make PDE5-Is promising pharmacologic agents against other benign urological diseases. This article reviews the literature and contains some previously unpublished data about characterizations and activities of PDE5 and its inhibitors in treating urological disorders. Scientific discoveries have improved our understanding of cell-signaling pathway in NO/cGMP-mediated SM relaxation in UGTs. Moreover, the clinical applications of PDE5-Is have been widely recognized. On-demand PDE5-Is are efficacious for most cases of ED, while daily-dosing and combination with testosterone are recommended for refractory cases. Soluble guanylate cyclase (sGC) stimulators also have promising role in the management of severe ED conditions. PDE5-Is are also the first rehabilitation strategy for postoperation or postradiotherapy ED for prostate cancer patients. PDE5-Is, especially combined with α-adrenoceptor antagonists, are very effective for benign prostatic hyperplasia (BPH) except on maximum urinary flow rate (Q max ) with tadalafil recently proved for BPH with/without ED. Furthermore, PDE5-Is are currently under various phases of clinical or preclinical researches with promising potential for other urinary and genital illnesses, such as priapism, premature ejaculation, urinary tract calculi, overactive bladder, Peyronie's disease, and female sexual dysfunction. Inhibition of PDE5 is expected to be an effective strategy in treating benign urological diseases. However, further clinical studies and basic researches investigating mechanisms of PDE5-Is in disorders of UGTs are required.

An Empirical vs Risk-Based Approach Algorithm to Intracavernosal Injection Therapy: A Prospective Study

Introduction

Intracavernosal injection (ICI) therapy is widely used for the treatment of erectile dysfunction (ED). Its use in practice is largely empirical and has not been validated with evidence-based approaches.

Aim

To compare two strategies for ICI, specifically a risk-based approach and an empiric-based approach, and assess the efficacy, patient satisfaction, and complication rates of the two treatment approaches.

Methods

After obtaining approval from the institutional review board, a prospective database of patients enrolled in the ICI program at the Johns Hopkins Hospital (Baltimore, MD, USA) from May 2012 through May 2014 was amassed. Demographic information, treatment outcomes, and subjective patient evaluations of sexual function (International Index of Erectile Function erectile function domain [IIEF-EF], Quality of Erection Questionnaire [QEQ], Sexual Quality of Life [SQoL], and Erectile Dysfunction Inventory of Treatment Satisfaction [EDITS]) were obtained at baseline and at 3 and 6 months. Two approaches were compared. Group 1 received empiric ICI treatment initially with prostaglandin E₁ (PGE1) 10 μg irrespective of ED etiology or severity. After initial dosing with PGE1 in the clinic, adjustments were made to titrate or change formulations pending on patient results. Group 2 received a risk-based approach, in which an algorithm that factored in ED etiology and number of ED risk factors was used for a bimix (papaverine 30 mg/mL, phentolamine 1 mg/mL), a low-dose trimix (papaverine 30 mg/mL, phentolamine 1 mg/mL, PGE1 10 μg/mL), or a high-dose trimix (papaverine 30 mg/mL, phentolamine 2 mg/mL, PGE1 40 μg/mL). Dose titration was permitted in the two groups. Statistical analysis was carried out using t-test and χ² analysis.

Main Outcome Measures

The study design was powered for a non-inferiority comparison of the two approaches, in which the primary end point was a 15-point difference on the EDITS score or a 20% difference in the IIEF-EF score.

Results

One hundred seventy-five patients were enrolled (57 in group 1, 118 in group 2) with 3- and 6-month follow-up at 57% and 35%, respectively, and similar between groups. Baseline patient characteristics and sexual function questionnaire responses were similar between groups 1 and 2, although group 1 reported higher-quality erections at baseline (QEQ score = 14.3 vs 7.3, P = .05) and had a smaller proportion of patients with prostatectomy (54.4% vs 74.6%, P = .02). In the two groups, QEQ score (mean = 10.78 vs 56.76, P < .05), SQoL score (mean = 38.41 vs 50.25, P < .05), and IIEF-EF score (mean = 7.51 vs 18.48, P < .05) improved with treatment. However, at 3 and 6 months, there were no statistically significant differences in responses for IIEF, QEQ, SQoL, or EDITS scores and no difference in failure or medication switch rates between groups. There were no significant differences in complication rates, although at 3 months group 2 reported a higher incidence of priapism and pain (23% vs 7.4%, P = .08).

Conclusion

Empiric and risk-based strategies for ICI therapy resulted in significant improvements across multiple domains of sexual function. Complication rates, satisfaction, and efficacy overall were similar between the two approaches. Clinicians can be reassured that no one approach to ICI therapy for ED management appears inferior to another.

Intracavernous delivery of clonal mesenchymal stem cells rescues erectile function in the streptozotocin-induced diabetic mouse

The major hurdle for the clinical application of stem cell therapy is the heterogeneous nature of the isolated cells, which may cause different treatment outcomes. The aim of this study was to examine the effectiveness of mouse clonal bone marrow-derived stem cells (BMSCs) obtained from a single colony by using subfractionation culturing method for erectile function in diabetic animals. Twelve-week-old C57BL/6J mice were divided into four groups: controls, diabetic mice, and diabetic mice treated with a single intracavernous injection of PBS (20 μL) or clonal BMSCs (3 × 10(5) cells/20 μL). Clonal BMSCs were isolated from 5-week-old C3H mice. Two weeks after treatment, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was stained with antibodies to PECAM-1, smooth muscle α-actin, neuronal nitric oxide synthase (nNOS), neurofilament, and phosphorylated endothelial NOS (phospho-eNOS). We also performed Western blot for phospho-eNOS, and eNOS in the corpus cavernosum tissue. Local delivery of clonal BMSCs significantly restored cavernous endothelial and smooth muscle cell contents, and penile nNOS and neurofilament contents, and induced eNOS phosphorylation (Ser1177) in diabetic mice. Intracavernous injection of clonal BMSCs induced significant recovery of erectile function, which reached 80-90% of the control values. Clonal BMSCs successfully restored erectile function through dual angiogenic and neurotrophic effects in diabetic mice. The homogenous nature of clonal mesenchymal stem cells may allow their clinical applications and open a new avenue through which to treat diabetic erectile dysfunction.

Resveratrol and sildenafil synergistically improve diabetes-associated erectile dysfunction in streptozotocin-induced diabetic rats

AIMS

Despite effective control of blood glucose levels in diabetic patients, complaints of diabetes-associated erectile dysfunction (ED) persist. Resveratrol has been indicated to possess anti-diabetic effects and therapeutic potential for ED. This study was conducted to observe the effect of resveratrol alone or in combination with sildenafil on ED in streptozotocin (STZ)-induced diabetic rats.

MAIN METHOD

Among 58 adult male STZ-induced (60 mg/kg) diabetic Sprague-Dawley rats, 48 STZ-induced diabetic rats were randomized equally to four groups: untreated diabetic rats, resveratrol (25mg/kg), sildenafil (5mg/kg) or resveratrol (25mg/kg) plus sildenafil (5mg/kg) through oral gavage for 8 weeks. Additionally, 12 age-matched rats were chosen as controls. Intracavernous pressure (ICP) and mean arterial blood pressure (MAP) were used to measure erectile function. The cavernous level of cyclic guanosine monophosphate (cGMP), protein and mRNA of endothelial NO synthase (eNOS), neuronal NOS (nNOS), and phosphodiesterase-5 (PDE5) was measured.

KEY FINDINGS

Treatment with either resveratrol or sildenafil improved ICP/MAP compared to the untreated diabetic rats (P<0.05). Treatment with resveratrol increased nNOS and eNOS expression, inhibited PDE5 expression, and increased the cavernous cGMP level compared to the untreated diabetic rats. Resveratrol significantly decreased superoxide anion and ROS production. Two-way ANOVA indicated that resveratrol in combination with sildenafil therapy had a significant synergistic effect in improving ICP/MAP and cavernous cGMP levels.

SIGNIFICANCE

Resveratrol improves diabetes-associated ED in rats. Combination therapies with resveratrol and sildenafil have a synergistic effect in improving ED. The mechanisms might be attributed to its anti-oxidative properties and NO-cGMP signaling pathway upregulation.

Combined sildenafil with vacuum erection device therapy in the management of diabetic men with erectile dysfunction after failure of first-line sildenafil monotherapy

OBJECTIVE

To evaluate the efficacy and safety of combination therapy of sildenafil plus vacuum erection devices in men with type 2 diabetes mellitus with moderate to severe erectile dysfunction who are dissatisfied with the results of using sildenafil alone.

METHODS

The study included 66 diabetes mellitus patients presenting erectile dysfunction for at least 6 months and dissatisfied with the use of 100 mg sildenafil monotherapy. The patients were randomized in two groups. Those in group A (n = 33) were instructed to use a vacuum erection device only, whereas those in group B (n = 33) were treated with combination therapy, including sildenafil 100 mg and a vacuum erection device. Erectile function was evaluated subjectively using the International Index of Erectile Function, Sexual Encounter Profile questionnaire questions 2 and 3 at visit 1 (baseline; study entry), visit 2 (4 weeks after baseline), and visit 3 (12 weeks after baseline; study end).

RESULTS

There were no significant differences in average patient age, duration of diabetes, duration of erectile dysfunction, baseline International Index of Erectile Function scores, hypertension, blood testosterone, smoking and alcohol consumption between two groups. Mean International Index of Erectile Function scores were significantly higher for group B at the 1-month (14.86 ± 2.17 vs 12.41 ± 2.63; P < 0.0001) and 3-months (17.53 ± 2.95 vs 14.29 ± 2.81; P < 0.0001) visits. Men in group B had better successful penetration (73.3% vs 46.6%) and successful intercourse (70% vs 46.6%) at 3 months compared with group A.

CONCLUSION

Combined use of sildenafil and vacuum erection device therapy significantly enhances erectile function, and it is well tolerated by diabetes mellitus patients not responding to first-line sildenafil alone.

Sildenafil improves erectile hardness in Chinese men with erectile dysfunction: a real-life study analyzed on age stratification

OBJECTIVE

To evaluate the clinical efficacy of sildenafil for the improvement of penile erection hardness in erectile dysfunction (ED) patients and to determine the relationship between this improvement in erection hardness and social and psychological functioning.

MATERIALS AND METHODS

From 2007 to 2008, a total of 4507 men diagnosed with ED were enrolled from 46 centers in China; 4039 of these patients were treated with sildenafil and asked to complete the Erectile Function domain of the International Index of Erectile Function, Erection Hardness Score, and Quality of Erection Questionnaire. The patients were divided into 5 groups on the basis of their age (group A: 20-30 years; group B: 31-40 years; group C: 41-50 years; group D: 51-60 years; and group E: >60 years).

RESULTS

A total of 3837 (95.0%) patients completed the entire study. After sildenafil treatment, the vast majority (96.3%) of the men were able to achieve grade 3-4 erection hardness. Patients with a better baseline erection hardness were more able to achieve grade 4 hardness after treatment (P <.001). Comparisons of the Erection Hardness Score improvement before and after treatment between the age-categorized groups also showed that the erection hardness improvement was much greater in men older than 50 years.

CONCLUSION

Sildenafil can help the vast majority of Chinese ED patients achieve grade 3-4 erection hardness. Grade 4 hardness can improve the patients' sexual life to a greater extent than grade 3 hardness. A marked improvement in erection hardness can be achieved in patients older than 50 years.

Effect of intensive lifestyle intervention on sexual dysfunction in women with type 2 diabetes: results from an ancillary Look AHEAD study

OBJECTIVE

Sexual dysfunction is a prevalent problem in obese women with type 2 diabetes. This study examined the effects of intensive lifestyle intervention (ILI) in these women.

RESEARCH DESIGN AND METHODS

Look AHEAD is a 16-center, randomized, controlled trial evaluating the health effects of ILI compared with a control group (diabetes support and education [DSE]). The Look AHEAD Sexual Function Ancillary study included 375 female participants at five Look AHEAD sites. Participants completed the Female Sexual Function Inventory (FSFI) and Beck Depression Inventory (BDI), and assessments of weight and cardiovascular risk factors at baseline and 1 year were made.

RESULTS

At baseline, 50% of the 229 participants who reported being sexually active met criteria for female sexual dysfunction (FSD); only BDI score was related to FSD. One-year weight losses were greater in the ILI group than in the DSE group (7.6 vs. 0.45 kg; P<0.001). Among women with FSD at baseline, those in the ILI group (N=60) compared with those in the DSE group (N=53) were significantly more likely to remain sexually active (83 vs. 64%; P<0.008), reported greater improvement in total FSFI scores and in most FSFI domains (P<0.05), and were more likely to experience remission of FSD (28 vs. 11%; P<0.04) at 1 year. No significant differences between ILI and DSE were seen in women who did not have FSD at baseline.

CONCLUSIONS

Participation in ILI appeared to have beneficial effects on sexual functioning among obese women with diabetes, particularly in those who had FSD at baseline.

Korean Society for Sexual Medicine and Andrology (KSSMA) Guideline on Erectile Dysfunction

In February 2011, the Korean Society for Sexual Medicine and Andrology (KSSMA) realized the necessity of developing a guideline on erectile dysfunction (ED) appropriate for the local context, and established a committee for the development of a guideline on ED. As many international guidelines based on objective evidence are available, the committee decided to adapt these guidelines for local needs instead of developing a new guideline. Considering the extensive research activities on ED in Korea, data with a high level of evidence among those reported by Korean researchers have been collected and included in the guideline development process. The latest KSSMA guideline on ED has been developed for urologists. The KSSMA hopes that this guideline will help urologists in clinical practice.

Erectile dysfunction

Erectile dysfunction is a common clinical entity that affects mainly men older than 40 years. In addition to the classical causes of erectile dysfunction, such as diabetes mellitus and hypertension, several common lifestyle factors, such as obesity, limited or an absence of physical exercise, and lower urinary tract symptoms, have been linked to the development of erectile dysfunction. Substantial steps have been taken in the study of the association between erectile dysfunction and cardiovascular disease. Erectile dysfunction is a strong predictor for coronary artery disease, and cardiovascular assessment of a non-cardiac patient presenting with erectile dysfunction is now recommended. Substantial advances have occurred in the understanding of the pathophysiology of erectile dysfunction that ultimately led to the development of successful oral therapies, namely the phosphodiesterase type 5 inhibitors. However, oral phosphodiesterase type 5 inhibitors have limitations, and present research is thus investigating cutting-edge therapeutic strategies including gene and cell-based technologies with the aim of discovering a cure for erectile dysfunction.

Intracavernous delivery of freshly isolated stromal vascular fraction rescues erectile function by enhancing endothelial regeneration in the streptozotocin-induced diabetic mouse

INTRODUCTION

Men with diabetic erectile dysfunction (ED) often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors.

AIM

To examine whether and how freshly isolated stromal vascular fraction (SVF) promotes cavernous endothelial regeneration and restores erectile function in diabetic animals.

METHODS

Eight-week-old C57BL/6J mice were used. Diabetes was induced by intraperitoneal injection of streptozotocin. SVF was isolated from epididymal adipose tissues of green fluorescence protein transgenic mice. At 8 weeks after the induction of diabetes, the animals were divided into six groups: controls, diabetic mice, and diabetic mice treated with a single intracavernous injection of phosphate-buffered saline (PBS) or SVF (1 × 10(4) cells, 1 × 10(5) cells, or 2 × 10(5) cells/20 µL, respectively).

MAIN OUTCOME MEASURES

Two weeks later, erectile function was measured by cavernous nerve stimulation. The penis was stained with antibodies to CD31, CD34, phosphohistone H3, phospho-endothelial nitric oxide synthase (eNOS), and vascular endothelial growth factor-A (VEGF-A). We also performed Western blot for phospho-eNOS and eNOS, and determined cyclic guanosine monophosphate (cGMP) concentration in the corpus cavernosum tissue.

RESULTS

Significant improvement in erectile function was noted in diabetic mice treated with SVF at concentrations of 1 × 10(5) and 2 × 10(5) cells, which reached up to 82% of the control values. Local delivery of SVF significantly increased cavernous endothelial cell proliferation, eNOS phosphorylation, and cGMP expression compared with that in the untreated group and the PBS-treated diabetic group. Intracavernous injection of SVF increased cavernous VEGF-A expression and induced recruitment of CD34(+)CD31(-) progenitor cells. Some SVF underwent differentiation into cavernous endothelial cells. SVF-induced promotion of cavernous angiogenesis and erectile function was abolished in the presence of VEGF-Trap, a soluble VEGF-A neutralizing antibody.

CONCLUSION

The results support the concept of cavernous endothelial regeneration by use of SVF as a curative therapy for diabetic ED.

Dropout in the treatment of erectile dysfunction with PDE5: a study on predictors and a qualitative analysis of reasons for discontinuation

INTRODUCTION

Phosphodiesterase type 5 inhibitors (PDE5) are currently the first line treatment for erectile dysfunction (ED). However, previous research shows that PDE5 treatments have high discontinuation rates. Understanding the reasons for discontinuing PDE5 will be necessary to optimize the response to treatment.

AIM

The main goals were: (i) to analyze discontinuation rate of PDE5; (ii) to identify the discontinuation predictors; and (iii) to study the reasons for discontinuation using a qualitative methodology.

MAIN OUTCOME MEASURES

The PDE5 discontinuation rates, predictors, and reasons for discontinuation treatment.

METHODS

A total of 327 men with clinical diagnosis for ED who had been treated with PDE5 were successfully interviewed by telephone, after giving their informed consent by snail mail. Telephone interviews, concerning their ongoing treatment, were carried out using a standardized questionnaire form with quantitative and qualitative items. Participation rate was 71.8%.

RESULTS

Of the total sample, 160 men (48.9%) had discontinued PDE5 treatment. The discontinuation rate was higher among men with diabetes (73%) and in iatrogenic group (65%), and lower in venogenic etiology (38.7%). We differentiated three groups of men who discontinued treatment (i) during the first 3 months (55.1%); (ii) between 4 and 12 months (26.9%); and (iii) after a period of 12 months (18%). Qualitative analyses revealed diverse reasons for discontinuation: non-effectiveness of PDE5 (36.8%), psychological factors (e.g., anxiety, negative emotions, fears, concerns, dysfunctional beliefs) (17.5%), erection recovery (14.4%), and concerns about the cardiovascular safety of PDE5 (8.7%) were the most common. Older men and men whose partners were involved in the treatment, were less likely to discontinue treatment.

CONCLUSION

Half the subjects discontinued medication. Mostly, there was a combination of factors that led to discontinuation: non-effectiveness and psychosocial factors appear to be the main reasons. Addressing those factors will allow following up with appropriate focus on relevant topics in order to improve compliance.

Neurotrophic effect of bone marrow mesenchymal stem cells for erectile dysfunction in diabetic rats

It has been demonstrated that intracavernous injection of bone marrow-derived mesenchymal stem cells (BM-MSCs) had beneficial effects on improving erectile function in type-1 diabetic rats. This study was designed to investigate the neurotrophic effect of BM-MSCs for type-1 diabetic rats. Streptozocin-induced type-1 diabetic rats were randomly divided into three groups: diabetic group, BM-MSCs-treated group and BM-MSCs-conditioned medium-treated group. At the 3d, 1 and 2w time points after BM-MSCs injection, three randomly selected rats in MSCs group were sacrificed and penile samples were harvested to detect BM-MSCs in penile tissue. Four weeks after intracavernous injection of BM-MSCs or BM-MSCs-conditioned medium, intracavernous pressure (ICP) was assessed to evaluate the erectile function. Immunohistochemistry was used to track labelled BM-MSCs in penile tissue and to detect neuronal nitric oxide synthase (nNOS) and neurofilament (NF) positive fibres in penile dorsal nerve. Enzyme lined immunosorbent assay (ELISA) was used to measure the concentrations of vascular endothelial growth factor (VEGF), nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in BM-MSCs-conditioned medium. BM- MSCs secreted detectable levels of VEGF, BDNF and NGF. Intracavernous injection of BM-MSCs improved erectile function in diabetic rats. The functional improvement was accompanied by promoted nNOS and NF positive nerve fibres within penile dorsal nerve in type-1 diabetic rats. Histological data revealed a time-dependent decrease in the number of BM-MSCs in the corpus cavernosum following injection. Furthermore, the beneficial effect of BM-MSCs was partially repeated by BM-MSCs-conditioned medium. Intracavernous injection of BM-MSCs is effective in improving nerve regeneration in diabetic rats. Paracrine effects of BM-MSCs are probably involved in the improvement.

Phosphodiesterase type 5 (PDE5) inhibitors in erectile dysfunction: the proper drug for the proper patient

INTRODUCTION

Erectile dysfunction (ED) is a very common multidimensional disorder affecting men worldwide. Physical illness, reaction to life stresses, or an unhappy couple relationship influence clinical outcome. Phosphodiesterase type 5 (PDE5) inhibitors are recognized as efficacious and well tolerated, and are the first-line treatment for ED. Sildenafil, tadalafil, and vardenafil are the most widely used and studied PDE5 inhibitors. Data acquired during a routine diagnostic workup for ED should be taken into account when choosing the best PDE5 inhibitor for the individual patient, creating an individualized treatment plan, and going beyond "experience-based" subjective opinion and unfounded ideas and prejudice regarding currently available drugs.

AIM

As the process of matching a given patient's profile to any selected PDE5 inhibitor often relies more on physician's personal convictions than on solid evidence, the aim of this review is to identify the main clinical, demographic, and relational factors influencing the choice of the PDE5 inhibitor to be used for the treatment of ED.

METHODS

A systematic literature search and current treatment guidelines were evaluated in a systematic manner.

MAIN OUTCOME MEASURES

The main clinical, cultural, and demographical factors to be considered for the treatment of ED have been identified.

RESULTS

Main factors influencing the choice of the treatment for ED have been described. A short list of items that may help in choosing the right PDE5 inhibitor for the treatment of different patients in daily clinical practice has been prepared.

CONCLUSIONS

The simple algorithms prepared should be a useful tool to be used in daily practice, which may help in choosing the right treatment for each subject affected by ED.

Intracavernous delivery of a designed angiopoietin-1 variant rescues erectile function by enhancing endothelial regeneration in the streptozotocin-induced diabetic mouse

OBJECTIVE

Patients with diabetic erectile dysfunction often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors. We examined the effectiveness of the potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous endothelial regeneration and restoring erectile function in diabetic animals.

RESEARCH DESIGN AND METHODS

Four groups of mice were used: controls; streptozotocin (STZ)-induced diabetic mice; STZ-induced diabetic mice treated with repeated intracavernous injections of PBS; and STZ-induced diabetic mice treated with COMP-Ang1 protein (days -3 and 0). Two and 4 weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations, Western blot analysis, and cGMP quantification. We also performed a vascular permeability test.

RESULTS

Local delivery of the COMP-Ang1 protein significantly increased cavernous endothelial proliferation, endothelial nitric oxide (NO) synthase (NOS) phosphorylation, and cGMP expression compared with that in the untreated or PBS-treated STZ-induced diabetic group. The changes in the group that received COMP-Ang1 restored erectile function up to 4 weeks after treatment. Endothelial protective effects, such as marked decreases in the expression of p47(phox) and inducible NOS, in the generation of superoxide anion and nitrotyrosine, and in the number of apoptotic cells in the corpus cavernosum tissue, were noted in COMP-Ang1-treated STZ-induced diabetic mice. An intracavernous injection of COMP-Ang1 completely restored endothelial cell-cell junction proteins and decreased cavernous endothelial permeability. COMP-Ang1-induced promotion of cavernous angiogenesis and erectile function was abolished by the NOS inhibitor, N-nitro-L-arginine methyl ester, but not by the NADPH oxidase inhibitor, apocynin.

CONCLUSIONS

These findings support the concept of cavernous endothelial regeneration by use of the recombinant Ang1 protein as a curative therapy for diabetic erectile dysfunction.

Standards for clinical trials in male sexual dysfunctions

INTRODUCTION

Clinical trials in male sexual dysfunction (MSD) are expanding. Consequently, there is a need for consensus standards in this area.

AIM

To develop an evidence-based, state-of-the-art consensus report on standards for clinical trials in MSD.

METHODS

A literature review was performed examining clinical trials in erectile dysfunction (ED), premature ejaculation (PE), delayed/absent ejaculation, libido disorders/loss of desire, hypogonadism, and Peyronie's disease, focusing on publications published in the last 20 years. This manuscript represents the opinions of eight experts from seven countries developed in a consensus process. This document was presented for peer review and debate in a public forum and revisions were made based on recommendations of chairpersons to the International Consultation on Sexual Medicine.

MAIN OUTCOME MEASURE

Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

RESULTS

According to experience and recent publications in dealing with clinical trials in sexual dysfunction, recommendations have been made for conducting trials in patients with ED, PE, delayed ejaculation, libido disorders, hypogonadism, and Peyronie's disease.

CONCLUSIONS

It is important that future clinical trials are conducted using standards upon which investigators can rely when reading manuscripts or conducting new trials in this field.

Safety of sildenafil citrate: review of 67 double-blind placebo-controlled trials and the postmarketing safety database

AIM

To review special safety topics associated with sildenafil and to document the tolerability of 50- and 100-mg doses, overall and by age, in men with erectile dysfunction (ED).

METHODS

Data were collated from 67 double-blind placebo-controlled (DBPC) trials (> 14,000 men) conducted by the manufacturer and from the manufacturer's postmarketing safety database (39,277 patients). The DBPC data were stratified by dose, starting dose and age (> or = 65 and > or = 75 years). Special safety topics included cardiovascular risk, priapism, non-arteritic anterior ischaemic optic neuropathy (NAION), impaired renal and hepatic function, drug interactions (i.e. nitrates, cytochrome P3A4 inhibitors, other ED therapies and alpha-blockers) and incorrect use.

RESULTS

Sildenafil was well tolerated at a dose of 50 or 100 mg in men with ED, overall, in those aged > or = 65 years, and in those aged > or = 75 years. Analyses of the databases did not reveal any causal link between sildenafil and cardiovascular events, or any new safety risks relating to cardiovascular events, priapism, NAION, hearing loss or drug interactions. In the small number of men with moderate impairment of renal function or hepatic function who were treated with sildenafil in DBPC trials, the safety profile was similar to that in men with no impairment of renal or hepatic function. Overdose with sildenafil was rare in the ED population. No new safety issues, emerging trends or adverse reactions were identified in conjunction with overdose, dependence, abuse or misuse.

CONCLUSION

This collated review confirms generally the good tolerability and established safety profile of sildenafil 50 and 100 mg in men with ED and reveals no new safety issues.

Efficacy and safety of tadalafil taken as needed for the treatment of erectile dysfunction in Asian men: results of an integrated analysis

We evaluated the efficacy and safety of as-needed tadalafil in a diverse clinical population (with varying patient demographics, disease severity, and comorbid medical conditions) of Asian men with erectile dysfunction (ED). An integrated analysis of five double-blind, placebo-controlled trials (N = 1 046) was performed. Patients were randomly assigned to receive 10 mg tadalafil (N = 185), 20 mg tadalafil (N = 510), or placebo (N = 351). Efficacy assessments included the International Index of Erectile Function (IIEF), Sexual Encounter Profile (SEP) diary and Global Assessment Question (GAQ). Patients receiving 10 mg or 20 mg tadalafil showed significant improvement from baseline-to-end point on the Erectile Function domain of the International Index of Erectile Function (IIEF-EF) domain score in all clinical sub-populations analyzed, compared with patients receiving placebo (P < 0.001). The 10-mg and 20-mg tadalafil groups showed a mean success rate of 64.1% and 70.5% for sexual intercourse attempts (SEP3, successful intercourse), respectively, compared with 33.4% in the placebo group (P < 0.001), and 85.5% and 85.4% reported improved erections at end point GAQ, respectively, versus 43.5% in the placebo group (P < 0.001). Tadalafil was well tolerated across all groups studied. Headache and back pain were the most frequently reported adverse events. Overall, tadalafil was effective and well tolerated across a diverse clinical spectrum of Asian men with ED.