Delay in Seeking Medical Help in Patients with New‐Onset Erectile Dysfunction Remained High Over and Despite the PDE5 Era—An Ecological Study

Pharmacological evaluation of a new nanoformulation in the erectile tissue of rabbits and humans

The failure of achieving a penile erection for satisfactory sexual intercourse is known as erectile dysfunction (ED). The primary mediator for penile erection is nitric oxide (NO). ED is often associated with endothelial/nitrergic dysfunction characterized by a reduction of the bioavailability of NO. Phosphodiesterase-5 inhibitors (PDE-5Is) clinical efficacy in the treatment of ED depends on the integrity of the NO-sGC-PKG pathway. In the present study, we probed the effect of sodium nitroprusside incorporated into mesoporous silica nanoparticles (MPSi-NP), which traps cyanide and slowly releases NO. MPSi-NP induced a maximal relaxation of 92.8 ± 5.2% in rabbit corpora cavernosa (RbCC), blunted by a soluble guanylate cyclase (sGC) inhibitor and blockers of calcium-dependent potassium channels. MPSi-NP abolished spontaneous contractions of human corpora cavernosa (HCC) strips. In addition, MPSi-NP induced maximal relaxation of phenylephrine precontracted HCC by 118.6 ± 3.6%, and in comparison, tadalafil induced a maximal relaxation of HCC by 98.3 ± 1.2%. Similarly, the sGC inhibitor blocked the MPSi-NP relaxation. MPSi-NP potentiated the relaxation induced by tadalafil. MPSi-NP increased cGMP levels in HCC strips by 2.6-fold and increased by 3.5-fold the phosphorylation level of the VASP protein, which is a downstream target to PKG. MPSi-NP effectively relaxes RbCC and HCC by activating the sGC-PKG pathway and potentiates the tadalafil response. MPSi-NP could be helpful in conditions where nitric oxide availability is decreased. A topical gel formulation of MPSi-NP could be used as a rescue therapy to treat true non-responders of PDE5Is drugs.

Attitudes and preferences towards erectile dysfunction treatment among men with fertility needs: insights from a clinical study

Erectile dysfunction (ED) is prevalent among males experiencing fertility challenges, yet attitudes towards actively treating ED in this group are under-researched. From a cohort of 1256 men with reproductive needs, 303 were identified with ED. The survey encompassed 296 respondents who correctly completed the second questionnaire, revealing that 50.3% sought ED treatment, with higher ED severity increasing the likelihood of seeking treatment. Infertile men were more likely to seek treatment than those with pregnancy loss (OR 3.18, 95% CI 1.74-5.83). Men with normal semen parameters were more open to ED therapy (OR 3.02, 95% CI 1.69-5.36), whereas those undergoing Assisted Reproduction Treatment were less inclined (OR 0.32, 95% CI 0.18-0.58). PDE-5 inhibitors (PDE-5Is) were preferred by 51.0% of those seeking treatment, with 29.7% of men with pregnancy loss and 60.1% of infertile men choosing PDE-5Is as their first option. Concerns included potential adverse effects of PDE-5Is on fetal health (78.7% of men with pregnancy loss) and on sperm quality (44.2% of infertile men). In conclusion, the different fertility requirements, semen parameters, and whether received ART are significant factors influencing the acceptance of treatment, PDE-5Is utilization among individuals in men with couple pregnancy loss is notably limited.

Erectile dysfunction prevalence in the United States: report from the 2021 National Survey of Sexual Wellbeing

BACKGROUND

There has been a great deal of public speculation regarding a surge in erectile dysfunction (ED) in younger men despite data consistently indicating that the ED prevalence rates increase with age.

AIM

In this study we sought to assess the prevalence and risk of experiencing ED in a nationally representative sample of men in the United States across various social groups, describe comorbidities, and examine barriers to treatment.

METHODS

Data from the 2021 National Survey of Sexual Wellbeing were analyzed by utilizing the Ipsos KnowledgePanel®, a probability-based online panel, for the purpose of obtaining US nationally representative data of adults aged 18 years and older. The analytic sample consisted of 1822 cisgender men ranging in age from 18 to 87 years, with a mean age of 47.5 years.

OUTCOMES

Study outcomes were ED as measured by the 5-item version of the International Index of Erectile Function (IIEF-5), as well as self-reported diagnosis by a medical professional, comorbidities with other health issues, medications taken for ED, and barriers to treatment.

RESULTS

The ED prevalence rate based on IIEF-5 scores was 24.2%. Prevalence increased with age: 52.2% of the 75+ age group, and 48.0% of the 65-74 age group meeting diagnostic criteria for ED. Diagnostic criteria were met for more participants in the 18-24 age group (17.9%) than the 25-34 (13.3%) or 35-44 (12.7%) age groups, but less than the 45-54 (25.3%) or 55-64 (33.9%) age groups. Only 7.7% (n = 141) of the sample reported having been diagnosed by a provider (n = 4 in 25-34, n = 6 in 35-44, n = 13 in 45-54, n = 39 in 55-64, n = 44 in 65-74, and n = 34 in ≥75-year olds), indicating a gap in access to treatment. The most common reason selected for not accessing care for ED concerns was a lack of need to see a provider in the past year.

CLINICAL IMPLICATIONS

The discrepancy between ED self-report and medical diagnosis is critical, given that ED can be an indication of underlying health risks.

STRENGTHS AND LIMITATIONS

This study is the first nationally representative update to information regarding the prevalence of ED in almost 2 decades. Standard administration of the IIEF-5 is limited to participants who have had sex in the last 6 months, so these rates do not include those men with ED who have been avoiding penetrative sex for a significant time.

CONCLUSION

The results indicate that ED prevalence and severity remain highest in older age groups and that most individuals who meet criteria for ED have not sought medical care related to this concern.

Estimating the risk of irreversible post-SSRI sexual dysfunction (PSSD) due to serotonergic antidepressants

BACKGROUND

Sexual dysfunction is a common side effect of Serotonergic antidepressants (SA) treatment, and persists in some patients despite drug discontinuation, a condition termed post-SSRI sexual dysfunction (PSSD). The risk for PSSD is unknown but is thought to be rare and difficult to assess. This study aims to estimate the risk of erectile dysfunction (ED) and PSSD in males treated with SAs.

METHODS

A 19-year retrospective cohort analysis was conducted using a computerized database of the largest HMO in Israel. ED was defined by phosphodiesterase-5 inhibitors prescriptions. 12,302 males aged 21-49 met the following criteria: non-smokers, no medical or psychiatric comorbidities or medications associated with ED, no alcohol or substance use. Logistic regression was used for estimation of ED risk in SA-treated subjects compared to non-SA-treated controls, assessed with and without the effects of age, body mass index (BMI), socioeconomic status (SES), depression and anxiety, yielding crude and adjusted odds ratios (cOR and aOR, respectively).

RESULTS

SAs were associated with an increased risk for ED (cOR = 3.6, p < 0.000001, 95% CI  2.8-4.8), which remained significant after adjusting for age, SES, BMI, depression and anxiety (aOR = 3.2, p < 0.000001, 95% CI  2.3-4.4). The risk for PSSD was 1 in 216 patients (0.46%) treated with SAs. The prevalence of PSSD was 4.3 per 100,000.

CONCLUSIONS

This work offers a first assessment of the small but significant risk of irreversible ED associated with the most commonly prescribed class of antidepressants which should enhance the process of receiving adequate informed consent for therapy.

Increasing access to erectile dysfunction treatment via pharmacies to improve healthcare provider visits and quality of life: Results from a prospective real-world observational study in the United Kingdom

OBJECTIVES

The Medicines and Healthcare Products Regulatory Agency in the United Kingdom (UK) formally reclassified sildenafil citrate 50 mg tablets as a pharmacy medicine (sildenafil-P) in 2017 for adult men with erectile dysfunction (ED). A 1-year prospective real-world observational study was conducted to track men's health behaviour, particularly their healthcare resource utilisation (HCRU) and quality of life (QoL) before and after the availability of sildenafil-P.

METHODS

Adult men with ED aged ≥18 years provided data at baseline (prior to launch of sildenafil-P) and every 3 months after the launch. Demographics, health characteristics, treatments at baseline and HCRU, including number of pharmacist and physician/nurse practitioner visits over time are reported. QoL-related outcomes were assessed via the Self-Esteem and Relationship Questionnaire (SEAR), 2-Item Patient Health Questionnaire and ratings of sexual satisfaction. Generalised linear models were used to assess the association of sildenafil-P use with total physician/nurse practitioner and pharmacist visits and QoL-related outcomes at 12 months.

RESULTS

Overall, 1162 men completed the survey at all 5 time points. The mean ± SD age was 59.02 ± 12.06 years; 55.42% reported having a moderate-to-severe ED. Hypertension (37.52%) and hypercholesterolaemia (31.50%) were the most common risk factors for ED. At baseline, 62.99% were not using any ED treatment. After adjusting for baseline visits/other covariates, mean physician/nurse practitioner (3.68 vs 2.87; P = .003) and pharmacist visits for any reason (2.10 vs 1.34; P < .001) at 12 months were significantly higher among sildenafil-P users than those who never used sildenafil-P. Sildenafil-P users also had significantly higher SEAR total and domain (sexual relationship and self-esteem) scores at 12 months.

CONCLUSION

Following the reclassification to a pharmacy medicine in the UK, sildenafil-P was associated with a higher number of physician/nurse practitioner and pharmacist visits for any reason. Sildenafil-P use was also associated with better QoL, although group differences were small in magnitude.

Trends in reported male sexual dysfunction over the past decade: an evolving landscape

We investigated changes in patterns of reported male SDs at a single academic centre over a 10-year time frame. Comprehensive data of 2013 patients consecutively assessed for the first time by a single Sexual Medicine expert between 2006 and 2019 has been analysed. All patients were assessed with a thorough sexual and medical history. Primary reason for seeking medical help at first assessment was recorded for all patients and categorized as: erectile dysfunction (ED), premature ejaculation (PE), low/reduced sexual desire/interest (LSD/I), Peyronie's disease (PD), and other SDs. Linear and logistic regression models tested the association between different reasons for seeking medical help and the time at first evaluation. Local polynomial regression model explored the probability of reporting different SDs over the analysed time frame. Median (IQR) age at first clinical assessment was 50 (38-61) years. Overall, most patients were assessed for ED (824; 41%), followed by PD (369; 18%), PE (322; 16%), LSD/I (204; 10%) and other SDs (294; 15%). Significant changes in terms of reported SD over the analysed time frame were observed. The likelihood of assessing patients for ED significantly increased up to 2013, with a decrease in the past 5 years (p < 0.001). PE assessment at presentation linearly decreased over time (OR: 0.94; 95% CI: 0.91-0.96; p < 0.001). Patients assessed during the past few years were more likely to report PD (OR: 1.20; 95% CI: 1.15-1.25; p < 0.001) and LSD/I (OR: 1.21; 95% CI: 1.16-1.26; p < 0.001), with a linear increase over the evaluated time frame. Likewise, patients were also more likely to report other SDs (Coeff: 1.06; 95% CI: 1.02-1.10; p = 0.004), with a linear increase over time. These results may reflect real changes in SD incidence, increased public awareness towards different SDs and the possible impact of novel treatments available on the market throughout the same time frame.

National Health and Wellness Survey exploratory cluster analysis of males 40-70 years old focused on erectile dysfunction and associated risk factors across the USA, Italy, Brazil and China

OBJECTIVES

Prior studies of erectile dysfunction (ED) tend to narrowly focus on relationships with specific comorbidities, rather than evaluating a more comprehensive array of risk factors and assessing naturalistic patterns among them. This study identifies natural clusters of male characteristics from a general population sample per country, quantifies ED dynamics in these profiles and compares profiles across the US, Italy, Brazil and China samples.

METHODS

National Health and Wellness Survey 2015 and 2016 patient-reported data on men aged 40-70 years (USA n = 15,652; Italy n = 2,521; Brazil n = 2,822; China n = 5,553) were analysed. Hierarchical agglomerative clustering identified clusters where predictors included demographics, health characteristics/behaviours, ED risk factors and provider visits in the past 6 months. Multinomial logistic regression assessed the independent utility of variables in predicting cluster membership, compared with the healthiest control cluster per country.

RESULTS

Different natural clusters were found across countries, with four clusters for the USA, Italy and China and three clusters for Brazil. Age, income, employment, health behaviours and ED risk factors predicted different cluster membership across countries. In the USA, Italy and Brazil, younger clusters were predicted by ED, unhealthy behaviours and ED risk factors. Unique cluster profiles were identified in China, with ED and ED risk factors (aside from hypertension) not predicting cluster membership, while socio-demographics and health behaviours were strongly predictive.

CONCLUSIONS

Natural cluster profiles revealed notable ED rates among adult males of age 40-70 in four different countries. Clusters were mainly predicted by unhealthy behaviours, ED risk factors and ED, regardless of level or presence of positive health characteristics and behaviours. This analysis identified meaningful subgroups of men with heightened ED risk factors, which can help healthcare providers to better recognise specific populations with the greatest need for intervention.

Is It Compulsory to Investigate for Erectile Dysfunction in Patients Presenting for Low Urinary Tract Symptoms?

BACKGROUND

Current European Association of Urology guidelines suggest investigation of erectile dysfunction (ED) among patients with lower urinary tract symptoms (LUTS) whenever there is a clinical suspicion.

OBJECTIVE

To assess factors predictive of ED, which may drive the need for a clinical assessment in men only presenting for LUTS.

DESIGN, SETTING, AND PARTICIPANTS

Data from 914 men presenting for LUTS at a single-center outpatient clinic and without a previous diagnosis of ED were analyzed.

INTERVENTION

All patients completed the International Prostatic Symptom Score (IPSS) and the International Index of Erectile Function-erectile function (IIEF-EF) questionnaires.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Logistic regression analyses tested potential predictors of ED and severe ED. The accuracy of the predictive models was assessed, and decision curve analyses (DCAs) tested their clinical benefit.

RESULTS AND LIMITATIONS

The median baseline IPSS score was 12 (7-19). IIEF-EF scores suggestive of unreported ED were observed in 503 (55%) patients; of all, 251 (27%) men showed severe ED. At logistic regression analysis, age (odds ratio [OR]: 1.04; p<0.001), IPSS score (OR: 1.04; p<0.001), diabetes mellitus (OR: 2.37; p=0.02), and smoking history (OR 1.36; p=0.03) were associated with unreported ED, after accounting for body mass index, hypertension, other cardiovascular diseases, and dyslipidemia. The same factors were associated with severe ED (all p≤0.03). The predictive model including these variables showed good accuracy for predicting ED (areas under the curve 0.69 and 0.72, respectively). However, DCAs showed no greater clinical benefit regarding identifying which patients should actually be screened for ED using these variables versus screening all patients with LUTS. Conversely, the net clinical benefit of the tested model was higher when predicting severe ED. As a limitation, we could not check prospectively the clinical impact of detecting ED in LUTS patients.

CONCLUSIONS

Given the importance of ED in terms of overall men's health, segregating patients to be investigated or not for ED according to the traditional risk factors did not emerge more clinically useful than screening all patients presenting for LUTS.

PATIENT SUMMARY

Lower urinary tract symptoms (LUTS) are frequently associated with erectile dysfunction (ED). Patients presenting for LUTS only in the everyday clinical practice should always be screened for ED and managed accordingly.

Medical treatment of erectile dysfunction: too many medical prescriptions?

Erectile dysfunction (ED) is a worldwide commonly reported condition; epidemiological data showed a prevalence ranging from 2.3 to 53.4% within different population subsets. In this context, the advent of phosphodiesterase type 5 inhibitors (PDE5is) in the second mid of 1990s has deeply changed the treatment scenario of this bothersome condition. Being user-friendly compounds with an excellent overall safety profile, PDE5is emerged as the first-line treatment for ED, thus overcoming topical alprostadil and intracavernous injections (ICIs). However, available data on treatment-utilization patterns and medical prescriptions of PDE5is showed a range of as wide as 22-78% of patients reporting to purchase PDE5is even without a proper medical prescription. Moreover, an increase in the recreational use of PDE5is among young men has been observed in the last decades, with a worrisome diffusion of potential health-risky behaviours associated with this habit. Indeed, treatment of ED should carefully follow internationally based clinical guidelines to avoid inappropriate drug prescriptions, which may eventually expose treated patients to drug-related side effects. Thereof, a careful assessment of the so-called modifiable and reversible ED risk factors along with a patient-tailored screening for potential contraindications to the treatment itself should be performed in every case. Lastly, although conclusive data still lack, the potential association between life-risky PDE5is side effects (i.e. cardiovascular adverse events, melanoma skin cancer and worsening of prostate cancer outcomes) should be carefully taken into account when counselling patients for ED treatment.

Sexual Dysfunction in Type 2 Diabetes at Diagnosis: Progression over Time and Drug and Non-Drug Correlated Factors

Aims

To present the longitudinal data of the SUBITO-DE study, a prospective survey involving male patients with new or recently diagnosed type 2 diabetes mellitus (T2DM) (<24 months).

Materials and Methods

Sexual function was assessed in male patients with T2DM at baseline (phase 1) and after a mean follow-up of 18 months (phase 2). Standard metabolic parameters and sexual and depressive symptoms were evaluated.

Results

Six of the 499 enrolled patients died of different causes during phase 1. Of the 493 surviving men invited to participate in phase 2, 450 (mean age 59.0±9.0 years) (90.2%) accepted and 43 (8.2%) were lost to follow-up. As compared to baseline, the proportion of the men who reported improvement in erectile dysfunction (ED) at follow-up was nearly double that of the men who reported worsening of ED (22.6% vs. 12.8%). The increase in frequency of sexual activity the men reported at follow-up assessment indicates that many never treated before baseline were taking an ED drug during the study period (106 subjects). Phosphodiesterase type 5 inhibitors (PDE5i) were the ED drugs most commonly taken at both baseline and follow-up. An overall improvement over baseline values was observed in metabolic targets for T2DM and depressive symptoms. Conversely, no change in lifestyle behaviors was recorded during the study.

Conclusions

Sexual dysfunction is a major concern in men with T2DM. The SUBITO-DE study demonstrates that, when combined with adequate counseling and tailored PDE5i therapy, an integrated approach to achieving metabolic targets in men with T2DM can improve sexual function as well as depressive symptoms.

Prevalence, correlates, attitude and treatment seeking of erectile dysfunction among type 2 diabetic Chinese men attending primary care outpatient clinics

To investigate the prevalence, correlates, attitude and treatment seeking behavior of erectile dysfunction (ED) in type 2 diabetes mellitus (T2DM) patients in the primary care setting, a multi-center cross-sectional survey using a structured anonymous self-administered questionnaire was performed in 10 general outpatient clinics. Of the 603 subjects (91% response rate), the prevalence of ED men, as defined by the International Index of Erectile Function, was 79.1%. Most subjects had mild ED (28.9%), followed by mild-to-moderate ED (27.9%), then moderate ED (13.4%) and severe ED (9%). Nearly 55% of those with ED did not consider themselves as having ED. Less than 10% of them had ever sought medical treatment, although 76.1% of them wished to receive management from doctor(s) should they be diagnosed with ED. They considered the most important management from doctors to be clinical assessment (41.7%), followed by management of potential underlying cause (37.8%), referral to specialist (27.5%), education (23.9%), prescription of phosphodiesterase type 5 inhibitors (16.9%) and referral to counseling service (6.7%). The prevalence of ED was strongly associated with subjects who thought they had ED (odds ratio (OR) = 90.49 (20.00–409.48, P< 0.001)) and were from the older age group (OR = 1.043 (1.011–1.076, P = 0.008)). In conclusion, ED is highly prevalent among T2DM men. The majority of them wanted management from doctors should they have ED, but only a minority would actually voice out the request. Screening of ED among T2DM men using structural questionnaire allowed the diagnosis of more than half of the ED cases, which otherwise would have gone undiagnosed.

Prediction model for penile prosthesis implantation for erectile dysfunction management

OBJECTIVE

Penile prosthesis surgery is indicated based on undesirability, contraindication or ineffectiveness of non-surgical options for erectile dysfunction. This definitive treatment is often delayed after initial diagnosis. Our objective was to develop a prediction tool based on a patient's clinical history to determine likelihood of ultimately receiving a penile prosthesis.

RESEARCH DESIGN AND METHODS

This retrospective analysis used claims data from Commercial and Medicare supplemental databases. Inclusion criteria were 18 years of age with 1 year of continuous enrollment at the first diagnosis of erectile dysfunction. Patients' demographics, co-morbidities and erectile dysfunction therapy were derived based on enrollment, medical and prescription histories.

MAIN OUTCOME MEASURES

The Cox proportional hazards model with stepwise selection was used to identify and quantify (using relative risk) factors associated with a future penile prosthesis implant. Co-morbidities and therapies present prior to the index erectile dysfunction diagnosis were analyzed as fixed covariates.

RESULTS

Approximately 1% of the dataset's population (N = 310,303 Commercial, N = 74,315 Medicare, respectively) underwent penile prosthesis implantation during the study period (3928 patients in the overall population: 2405 patients [0.78%] in the Commercial and 1523 patients [2.05%] in the Medicare population). Factors with the greatest predictive strength of penile prosthesis implantation included prostate cancer diagnosis (relative risk: 3.93, 2.29; 95% CI, 3.57-4.34, 2.03-2.6), diabetes mellitus (2.31, 1.23; 2.12-2.52, 1.1-1.37) and previous treatment with first-line therapy (1.39, 1.33; 1.28-1.5, 1.2-1.47) (all P < 0.01).

CONCLUSION

The presence and extent of specific medical history factors at the time of erectile dysfunction diagnosis predict an individual's future likelihood of penile prosthesis. Calculating the likelihood of penile prosthesis implantation based on the weight of these factors may assist clinicians with the definition of a care plan and patient counseling. The precision of the model may be limited by factors beyond medical history information that possibly influence the decision to proceed to surgery.

Help-seeking behavior for erectile dysfunction: a clinic-based survey in China

The behavior of Chinese patients seeking help for erectile dysfunction (ED) has not been described in detail. This was an observational study conducted using an outpatient clinic-based questionnaire survey of ED patients. From 2008 to 2009, physicians in 10 medical centers in China enrolled 2693 men (aged 25–70 years) diagnosed with ED. The diagnosis was based on the International Index of Erectile Function 5 (IIEF-5) Questionnaire. The men completed a survey that asked questions about demographics, marital status, education level and household income as well as help-seeking behavior and awareness of medical therapy. The mean age of the 2693 men was 43.4 ± 5.3 years; 73% were <50-years-old and 49% had a high household income. The mean time between noticing ED and taking the first treatment was 4.3 ± 2.1 months. Of the 2577 respondents, physicians (54%) and the internet (52%) were most frequently consulted sources for information about ED. Young ED patients preferred using the internet and older patients preferred consulting with physicians. Western medicine (19%) and traditional Chinese medicine (16%) were most frequently used for treatment. Young ED patients preferred to first search the internet for information, whereas older patients first asked physicians for help. Side effects of treatment were the greatest concern, especially for older patients. Physicians and the internet are frequently consulted for ED information and therapy. On the basis of these survey results, we believe that physicians in China should enhance health education about ED, especially via the internet.

Endocrine evaluation of erectile dysfunction

Erectile dysfunction is highly prevalent, affecting up to half of men in their 50-70s, and has been variably associated to a variety of causes including unhealthy lifestyles, such as smoking or overweight, or comorbidities such as hypertension, diabetes mellitus, and neurological disorders. General interest toward ED has exploded since the introduction of phosphodiesterase type 5 inhibitors-oral drugs that are widely accepted as the first line treatment in patients suffering from this conditions. In the last decade, the time lapse between first symptoms of sexual disorders and seeking of medical advice has greatly reduced. Unfortunately, none of the PDE5i has been proven curative, but rather acts as a symptomatic treatment. The availability of very active and safe drugs, however, diminished the space for diagnosis and search of etiological treatments. This is particularly true for the several endocrinopathies associated with ED. A number of epidemiological data support an inverse relationship between sexual health and testosterone levels, and it is well accepted that testosterone deficiency is a good marker of sexual and physical frailty. However, several other hormones, including LH, prolactin, TSH, and FT4 are involved in sexual functioning and should be investigated in a proper work-out of ED. Existing guidelines provide information almost entirely focusing on late-onset hypogonadism and therapeutic strategies; this mini-review aims to provide a wider spectrum of the diagnostic endocrine work-out of ED patients unrevealing the complexity of conditions, overt or subclinical, which can affect ED.

Phosphodiesterase type 5 inhibitors as a treatment for erectile dysfunction: Current information and new horizons

INTRODUCTION

Over the past 15 years, the discovery and development of oral medications that selectively inhibit the enzyme phosphodiesterase type 5 (PDE5) have revolutionised the treatment of erectile dysfunction (ED). Currently, three PDE5 inhibitors are widely available clinically, i.e., sildenafil, vardenafil and tadalafil. New PDE5 inhibitors, including avanafil and udenafil, are now in clinical use in a few countries, and other compounds are under development.

METHODS

We describe the current use and future direction of PDE5 inhibitors in the treatment of ED.

RESULTS AND CONCLUSION

Each PDE5 inhibitor has an excellent and comparable efficacy and tolerability. These drugs are highly effective for ED of various causes, and are effective in preventing ED after radical prostatectomy. However, whilst being at least 60% effective, PDE5 inhibitors are still ineffective in at least 30% of patients, prompting current research into other pharmacological targets for ED.

A critical analysis of the role of testosterone in erectile function: from pathophysiology to treatment-a systematic review

CONTEXT

Androgen modulation of erectile function (EF) is widely accepted. However, the use of testosterone replacement therapy (TRT) in men with erectile dysfunction (ED) has generated an unprecedented debate.

OBJECTIVE

To summarize the relevant data on the incidence, diagnosis, and management of ED coexisting with hypogonadism and to develop a pathophysiology-based treatment algorithm.

EVIDENCE ACQUISITION

We reviewed the relevant medical literature, with a particular emphasis on original molecular studies, prospective observational data, and randomized controlled trials performed in the past 20 yr.

EVIDENCE SYNTHESIS

Testosterone modulates nearly every component involved in EF, from pelvic ganglions to smooth muscle and the endothelial cells of the corpora cavernosa. It also regulates the timing of the erectile process as a function of sexual desire, coordinating penile erection with sex. Epidemiologic studies confirm the significant overlap of hypogonadism and ED; however, most guidelines do not consider the differential diagnosis of hypogonadism or the relevance of subclinical disease. Various clinical tools can help the physician to assess and restore androgen levels in men with ED. Special attention is given to fertility-sparing treatments, due to the increasing number of older men desiring fatherhood. The simultaneous use of phosphodiesterase type 5 inhibitors (PDE5-Is) and TRT has recently been questioned. Originally proposed as a salvage therapy for nonresponders to PDE5-Is, this approach has been inappropriately transformed into a combination therapy. Clinical data are consistent when reinterpreted in the proper framework, whereas molecular evidence remains controversial.

CONCLUSIONS

A body of molecular and clinical evidence supports the use of TRT in hypogonadal patients with ED, although the benefit-risk ratio is uncertain in advanced age. Critical appraisal of this evidence enabled the development of a pathophysiology-oriented algorithm designed to avoid inappropriate treatments and support whether to start with TRT, PDE5-I only, or both. Apparently divergent findings are reconciled when TRT is correctly indicated. An improved diagnosis and individualized management is desirable in light of the many available options.