Comparative Effectiveness and Safety of Oral Phosphodiesterase Type 5 Inhibitors for Erectile Dysfunction: A Systematic Review and Network Meta-analysis

Standards for Clinical Trials in Male and Female Sexual Dysfunction: III. Unique Aspects of Clinical Trials in Male Sexual Dysfunction

This series of articles, Standards for Clinical Trials in Male and Female Sexual Dysfunction, began with the discussion of a common expected standard for clinical trial design in male and female sexual dysfunction, a common rationale for the design of phase I to IV clinical trials, and common considerations for the selection of study population and study duration in male and female sexual dysfunction. The second article in this series discussed fundamental principles in development, validation, and selection of patient- (and partner-) reported outcome assessment. The third and present article in this series discusses selected aspects of sexual dysfunction that are that are unique to male sexual dysfunctions and relevant to the conduct of clinical trials of candidate treatments for men.

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.

Intraoperative and postoperative feasibility and safety of total tubeless, tubeless, small-bore tube, and standard percutaneous nephrolithotomy: a systematic review and network meta-analysis of 16 randomized controlled trials

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is performed to treat relatively large renal stones. Recent publications indicate that tubeless and total tubeless (stentless) PCNL is safe in selected patients. We performed a systematic review and network meta-analysis to evaluate the feasibility and safety of different PCNL procedures, including total tubeless, tubeless with stent, small-bore tube, and large-bore tube PCNLs.

METHODS

PubMed, Cochrane Central Register of Controlled Trials, and EMBASE™ databases were searched to identify randomized controlled trials published before December 30, 2013. One researcher examined all titles and abstracts found by the searches. Two investigators independently evaluated the full-text articles to determine whether those met the inclusion criteria. Qualities of included studies were rated with Cochrane's risk-of-bias assessment tool.

RESULTS

Sixteen studies were included in the final syntheses including pairwise and network meta-analyses. Operation time, pain scores, and transfusion rates were not significantly different between PCNL procedures. Network meta-analyses demonstrated that for hemoglobin changes, total tubeless PCNL may be superior to standard PCNL (mean difference [MD] 0.65, 95% CI 0.14-1.13) and tubeless PCNLs with stent (MD -1.14, 95% CI -1.65--0.62), and small-bore PCNL may be superior to tubeless PCNL with stent (MD 1.30, 95% CI 0.27-2.26). Network meta-analyses also showed that for length of hospital stay, total tubeless (MD 1.33, 95% CI 0.23-2.43) and tubeless PCNLs with stent (MD 0.99, 95% CI 0.19-1.79) may be superior to standard PCNL. In rank probability tests, small-bore tube and total tubeless PCNLs were superior for operation time, pain scores, and hemoglobin changes.

CONCLUSIONS

For hemoglobin changes, total tubeless and small-bore PCNLs may be superior to other methods. For hospital stay, total tubeless and tubeless PCNLs with stent may be superior to other procedures.

Intraoperative and postoperative feasibility and safety of total tubeless, tubeless, small-bore tube, and standard percutaneous nephrolithotomy: a systematic review and network meta-analysis of 16 randomized controlled trials

Background

Percutaneous nephrolithotomy (PCNL) is performed to treat relatively large renal stones. Recent publications indicate that tubeless and total tubeless (stentless) PCNL is safe in selected patients. We performed a systematic review and network meta-analysis to evaluate the feasibility and safety of different PCNL procedures, including total tubeless, tubeless with stent, small-bore tube, and large-bore tube PCNLs.

Methods

PubMed, Cochrane Central Register of Controlled Trials, and EMBASE™ databases were searched to identify randomized controlled trials published before December 30, 2013. One researcher examined all titles and abstracts found by the searches. Two investigators independently evaluated the full-text articles to determine whether those met the inclusion criteria. Qualities of included studies were rated with Cochrane’s risk-of-bias assessment tool.

Results

Sixteen studies were included in the final syntheses including pairwise and network meta-analyses. Operation time, pain scores, and transfusion rates were not significantly different between PCNL procedures. Network meta-analyses demonstrated that for hemoglobin changes, total tubeless PCNL may be superior to standard PCNL (mean difference [MD] 0.65, 95% CI 0.14–1.13) and tubeless PCNLs with stent (MD -1.14, 95% CI -1.65–-0.62), and small-bore PCNL may be superior to tubeless PCNL with stent (MD 1.30, 95% CI 0.27–2.26). Network meta-analyses also showed that for length of hospital stay, total tubeless (MD 1.33, 95% CI 0.23–2.43) and tubeless PCNLs with stent (MD 0.99, 95% CI 0.19–1.79) may be superior to standard PCNL. In rank probability tests, small-bore tube and total tubeless PCNLs were superior for operation time, pain scores, and hemoglobin changes.

Conclusions

For hemoglobin changes, total tubeless and small-bore PCNLs may be superior to other methods. For hospital stay, total tubeless and tubeless PCNLs with stent may be superior to other procedures.

A Randomized, Placebo-Controlled, Double-Blind, Multi-Center Therapeutic Confirmatory Study to Evaluate the Safety and Efficacy of Avanafil in Korean Patients with Erectile Dysfunction

A multi-center, randomized, double-blind, placebo-controlled study was conducted with 158 subjects who were randomized to placebo or avanafil 50, 100, and 200 mg on demand for 8 weeks to evaluate the safety, tolerability, and efficacy of avanafil in the treatment of erectile dysfunction (ED) in Korean men. The primary outcome was the erectile function (EF) domain score of the International Index of Erectile Function (IIEF) questionnaire. Secondary outcomes included changes in the scores of IIEF questions 3 and 4 (IIEF Q3, Q4) from baseline, changes in all domain scores in the IIEF from baseline, Sexual Encounter Profile questions 2-5 (SEP2-5), the Global Efficacy Assessment Question (GEAQ), and the number of subjects whose EF domain score at the 8th week visit was ≥ 26. After 8 weeks of treatment, the dose groups except avanafil 50 mg scored significantly higher on the IIEF-EF domain from baseline than the placebo group. The changes from baseline in the avanafil group in IIEF Q3 (all doses) and Q4 (200 mg alone) were higher than the placebo group. The differences between avanafil and placebo groups were significant in SEP2 (100 and 200 mg) and SEP3-5 (200 mg). The differences in the GEAQ "Yes" response were also significant in the avanafil 100 and 200 mg groups. Regarding the ratio of normal EF at the end of the study, avanafil 200 mg differed significantly from the placebo. Most treatment-associated adverse events were mild and resolved spontaneously. This is a clinical trial study and was registered at www.ClinicalTrials.gov (Identifier: NCT02477436).

Effects of taking tadalafil 5 mg once daily on erectile function and total testosterone levels in patients with metabolic syndrome

We aimed to evaluate the efficacy of tadalafil 5 mg once-daily treatment on testosterone levels in patients with erectile dysfunction (ED) accompanied by the metabolic syndrome. A total of 40 men with metabolic syndrome were evaluated for ED in this study. All the patients received 5 mg tadalafil once a day for 3 months. Erectile function was assessed using the five-item version of the International Index of Erectile Function (IIEF) questionnaire. Serum testosterone, follicle-stimulating hormone and luteinising hormone levels were also evaluated, and blood samples were taken between 08.00 and 10.00 in the fasting state. All participants have three or more criteria of metabolic syndrome. At the end of 3 months, mean testosterone values and IIEF scores showed an improvement from baseline values (from 3.6 ± 0.5 to 5.2 ± 0.3, from 11.3 ± 1.9 to 19 ± 0.8 respectively). After the treatment, serum LH levels were decreased (from 5.6 ± 0.6 to 4.6 ± 0.5). There was significantly difference in terms of baseline testosterone and luteinising hormone values and IIEF scores (p < .05). Based on our findings, we recommend tadalafil 5 mg once daily in those men with erectile dysfunction especially low testosterone levels accompanied by metabolic syndrome.

A Perspective on Middle-Aged and Older Men With Functional Hypogonadism: Focus on Holistic Management

CONTEXT

Middle-aged and older men (≥50 years), especially those who are obese and suffer from comorbidities, not uncommonly present with clinical features consistent with androgen deficiency and modestly reduced testosterone levels. Commonly, such men do not demonstrate anatomical hypothalamic-pituitary-testicular axis pathology but have functional hypogonadism that is potentially reversible.

EVIDENCE ACQUISITION

Literature review from 1970 to October 2016.

EVIDENCE SYNTHESIS

Although definitive randomized controlled trials are lacking, evidence suggests that in such men, lifestyle measures to achieve weight loss and optimization of comorbidities, including discontinuation of offending medications, lead to clinical improvement and a modest increase in testosterone. Also, androgen deficiency-like symptoms and end-organ deficits respond to targeted treatments (such as phosphodiesterase-5 inhibitors for erectile dysfunction) without evidence that hypogonadal men are refractory. Unfortunately, lifestyle interventions remain difficult and may be insufficient even if successful. Testosterone therapy should be considered primarily for men who have significant clinical features of androgen deficiency and unequivocally low testosterone levels. Testosterone should be initiated either concomitantly with a trial of lifestyle measures, or after such a trial fails, after a tailored diagnostic work-up, exclusion of contraindications, and appropriate counseling.

CONCLUSIONS

There is modest evidence that functional hypogonadism responds to lifestyle measures and optimization of comorbidities. If achievable, these interventions may have demonstrable health benefits beyond the potential for increasing testosterone levels. Therefore, treatment of underlying causes of functional hypogonadism and of symptoms should be used either as an initial or adjunctive approach to testosterone therapy.

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.

Time of onset of vardenafil orodispersible tablet in a real-life setting - looking beyond randomized clinical trials

BACKGROUND

A rapid onset of action for phosphodiesterase type 5 inhibitors (PDE5is) emerged to be of clinical importance in men treated for erectile dysfunction (ED). Data from randomized clinical trials (RCTs) showed a rapid onset of action for vardenafil 10 mg orodispersible tablet (ODT). However, the effectiveness of vardenafil ODT has never been tested in a real-life setting. We assessed the efficacy and time to onset of action of vardenafil ODT in men seeking medical help for ED in the everyday real-life clinical practice.

RESEARCH DESIGN AND METHODS

Patients completed a baseline and follow-up International Index of Erectile Function (IIEF), along with a 8-item self-administered questionnaire about onset of action and overall treatment outcomes. Descriptive statistics tested efficacy rates, patient timing of drug intake and time to post-dosing onset of action.

RESULTS

Overall, 118(59.9%) patients used vardenafil ODT. Satisfactory erections for vaginal penetration were reported in 39(34.5%) and 26(21.8%), patients in =15 and =30, minutes post-dosing, respectively. Minimal Clinically Important Differences (MCIDs) criteria and Yang's criteria for responders were obtained in 80(67.8%) and 72(60.8%) patients.

CONCLUSIONS

This study showed that one in three patients had satisfactory erection for vaginal penetration in less than 15 min post-dosing in the real-life setting.

Applications of Higenamine in pharmacology and medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum has been used as local and traditional medicines in many asian regions for the treatment of various diseases such as collapse, syncope, painful joints, oedema, bronchial asthma et al. Higenamine, a plant-based alkaloid, was initially isolated from Aconitum and identified as the active cardiotonic component of Aconitum. It has been tested as a candidate of pharmacologic stress agent in the detection of coronary artery diseases (CADs) and now researchers have just accomplished the phase III clinical studies successfully in China. Besides, a large number of studies have revealed the various pharmacological properties and potentially multi-spectral medical applications of higenamine. However, to date, no comprehensive review on higenamine has been published.

AIM OF THE REVIEW

This present paper aims to compile a comprehensive update regarding the biochemistry, pharmacokinetic features, pharmacological activities, clinical and potential clinical uses and toxicities on higenamine with the ultimate objective of providing a guide for future research on this drug.

MATERIALS AND METHODS

The selection of relevant data was made through a search using the keyword "higenamine" in "Web of science", "Pubmed", and "China Knowledge Resource Integrated (CNKI)". Information was also acquired from local classic herbal literature, government reports and conference papers.

RESULTS

In addition to Aconitum, higenamine also exists in many other plants including Tinospora crispa, Nandina domestica T_HUNBERG, Gnetum Parvifolium C.Y. Cheng, sarum Heterotropoides_,Nelumbo nucifera_,N.nucifera. The pharmacokinetic studies conducted in animals and humans showed that higenamine conformed to a two-compartment pharmacokinetic model. Studies over the last four decades on higenamine have revealed its various pharmacological properties such as positive inotropic and chronotropic effect, activating slow channel effect, vascular and tracheal relaxation effect, anti-thrombotic, anti-apoptotic and anti-oxidative effect, anti-inflammatory and immunomodulatory effect. This phytochemical constituent has shown its potential therapeutic effects for diseases like heart failure, disseminated intravascular coagulation (DIC), shock, arthritis, asthma, ischemia/reperfusion (I/R) injuries and erectile dysfunction.

CONCLUSIONS

Extensive basic and clinical studies on higenamine showed valuable therapeutic effects on different disorders. However, the underlying mechanisms of higenamine have not been established. Therefore, the safety, tolerability and efficacy of higenamine are as yet, not fully understood. Additionally, some of the studies were small sample-sized and unreliable. To sum up, there is a need for deeper investigation in the mechanisms of higenamine action, as well as well-designed preclinical and clinical trials studies to test the safety and clinical value of the drug.

When "Chems" Meet Sex: A Rising Phenomenon Called "ChemSex"

BACKGROUND

The term "chemsex" was coined to indicate the voluntary intake of psychoactive and non psychoactive drugs in the context of recreational settings to facilitate and/or to enhance sexual intercourses mostly among men who have sex with other men (MSM).

OBJECTIVE

The authors aimed to review the mechanisms of action, the toxicity and the pattern of use and abuse of substances involved in "chemsex" practice together with the sociocultural background underlying it and the health-related consequences that they may have.

RESULTS

Gamma-hydroxybutyrate, gamma-butyrolactone,1,4-butanediol, mephedrone, methamphetamine, sildenafil, tadalafil, vardenafil and alkyl nitrites have been described in their role of "chemsex drugs" including pharmacological action and in their implication to impair capacities to chose sexual partners and consensual sex. Moreover, it has been demonstrated that sexual activity over protracted length of time under the influence of chemsex drugs can result in rectal trauma or penile abrasions and a significant increase of the risk of transmission of sexual transmitted diseases, especially in case of condomless intercourses, which are frequent in this context, representing therefore a serious health threat.

CONCLUSION

One of the major problems to establish health policy priority interventions for chemsex is the lack of available epidemiological data on the issue. Finally, social actions should be taken in order to break down the barriers that currently exist among chemsex drug users in accessing services, including the shame and stigma often associated with drug use. In conclusion, more specific resources to face high risks of infections and HIV transmission are required in bisexual and homosexual individuals having SUID: sex under the influence of drugs.

From Age-Related Cognitive Decline to Alzheimer's Disease: A Translational Overview of the Potential Role for Phosphodiesterases

Phosphodiesterase inhibitors (PDE-Is) are pharmacological compounds enhancing cAMP and/or cGMP signaling. Both these substrates affect neural communication by influencing presynaptic neurotransmitter release and postsynaptic intracellular pathways after neurotransmitter binding to its receptor. Both cAMP and cGMP play an important role in a variety of cellular functions including neuroplasticity and neuroprotection. This chapter provides a translational overview of the effects of different classes of PDE-Is on cognition enhancement in age-related cognitive decline and Alzheimer's disease (AD). The most effective PDE-Is in preclinical models of aging and AD appear to be PDE2-Is, PDE4-Is and PDE5-Is. Clinical studies are relatively sparse and so far PDE1-Is and PDE4-Is showed some promising results. In the future, the demonstration of clinical proof of concept and the generation of isoform selective PDE-Is are the hurdles to overcome in developing safe and efficacious novel PDE-Is for the treatment of age-related cognitive decline and cognitive dysfunction in AD.

Advances in stem cell research for the treatment of male sexual dysfunctions

PURPOSE OF REVIEW

To summarize recent literature on basic stem cell research in erectile dysfunction in cavernous nerve injury, aging, diabetes, and Peyronie's disease and to provide a perspective on clinical translation of these cellular therapies.

RECENT FINDINGS

Stem cell research has been concentrated on mesenchymal stem (stromal) cells from bone marrow and adipose tissue. Application of both cell types has produced positive effects on erectile function in various animal models of erectile dysfunction. In acute animal models, such as cavernous nerve injury-induced erectile dysfunction and chemically induced Peyronie's disease, engraftment and differentiation have not been observed, and stem cells are believed to interact with the host tissue in a paracrine fashion, whereas in chronic disease models some evidence suggests both engraftment and paracrine factors may support improved function. Clinical trials are now investigating therapeutic efficacy of cellular therapy, whereas the first safety studies in humans have recently been published.

SUMMARY

Evidence from preclinical studies has established stem cells as a potential curative treatment for erectile dysfunction and early phase clinical trials are currently performed.

A meta-regression evaluating the effectiveness and prognostic factors of oral phosphodiesterase type 5 inhibitors for the treatment of erectile dysfunction

The effectiveness of phosphodiesterase type 5 inhibitors (PDE5-Is) for erectile dysfunction (ED) varies considerably among trials, but available studies investigating the factors that affect the effectiveness are few and findings are not consistent. A systematic search was performed in PubMed, Cochrane Library, and EMBASE to identify randomized controlled trials comparing PDE5-Is with placebo for the treatment of ED. The methodological quality of included studies was assessed by the Cochrane Collaboration's tool for assessing risk of bias. The associations between prespecified study-level factors and effectiveness were tested by a random effects meta-regression model. This study included 93 trials with 26 139 patients. When all PDE5-Is were grouped together, Caucasian ethnicity was associated with 15.636% (95% confidence interval [CI]: 0.858% to 32.579%) increase in risk ratio (RR) for Global Assessment Questionnaire question-1 (GAQ-1), and 1.473 (95% CI: 0.406 to 2.338) score increase in mean difference (MD) for posttreatment International Index of Erectile Function-Erectile Function domain score (IIEF-EF), compared to Asian ethnicity. A one-score increase in baseline IIEF-EF was associated with −5.635% (95% CI: −9.120% to −2.017%) reduction in RR for GAQ-1, and −0.229 (95% CI: −0.425 to −0.042) score decrease in MD for posttreatment IIEF-EF. In conclusion, PDE5-Is are more effective in Caucasians than Asians, and in patients with more severe ED.

[Efficacy and tolerance of PDE-5 in the treatment of erectile dysfunction in schizophrenic patients: A literature review]

INTRODUCTION

Sexual dysfunction is an important public health problem in men and is associated with reduced quality of life. It is more common in patients with schizophrenia. It is well-established that antipsychotic drugs cause sexual dysfunction with consequences on the quality of life of patients, adherence to treatment, and public health costs. Phosphodiesterase type 5 inhibitors (PDE5 inhibitors) are indicated for the management of erectile dysfunction. However, there is little information on such treatment in schizophrenic patients. This literature review aimed to summarize the current data on the efficacy and tolerability of PDE-5 inhibitors in the erectile dysfunction in schizophrenic patients.

MATERIAL AND METHODS

PubMed, PsycInfo and Cochrane databases were searched for studies published until August 2014.

RESULTS

Only 6 studies met the inclusion criteria. Three were randomized, double-blind, cross-over, placebo-controlled trials and three were open studies. Various scales were used to measure erectile and orgasmic function, desire, satisfaction during intercourse, overall satisfaction, quality of life and intensity of schizophrenic symptoms. In the 3 randomized studies (one with sildenafil 25-50 mg, one with lodenafil carbonate 80 mg/j and the last one with tadalafil 10 mg), the rate of participants who completed the trial was high (around 95 %). All three included patients with schizophrenia or schizophrenia spectrum disorders. Patients reported significant improvement on sexual dysfunction. However, no statistical difference was reported between lodenafil and placebo, on different scales, suggesting a very important placebo effect in patients with schizophrenia. All three found a good tolerance of PDE-5 inhibitors. Side effects were rare and were mainly nasal congestion, headaches, nausea and dizziness. There were no major side effects or drug interactions. Considering the 3 open studies, 2 involved sildenafil and one tadalafil. All concluded in improved erectile and orgasmic function, desire, satisfaction during intercourse, overall satisfaction, and even the quality of life when it was studied. However, very few patients were included.

DISCUSSION

Little data are available on the use of PDE5 inhibitors in schizophrenic patients. The 6 studies included few patients which reduces the power and the scope of their conclusions. There is also an important bias due to the use of self-questionnaires. The methodologies of the studies differ in many aspects which limits the comparability. Inclusion and exclusion criteria, drugs used and scales varied among the studies. However, the management of erectile disorder seems to be a consistent target in an integrative approach for the overall well-being of schizophrenic patients. PDE-5 inhibitors appear to be safe and could improve erectile function in schizophrenic patients.

CONCLUSION

In total, the current data suggest efficiency and good tolerance of the use of PDE-5 inhibitors in schizophrenic patients with erectile dysfunction. However, further studies focusing on PDE-5 inhibitors are needed to more deeply assess their efficacy and safety in patients with schizophrenia.

Effects of tadalafil treatment combined with physical activity in patients with low onset hypogonadism: results from a not-randomized single arm phase 2 study

PURPOSE

To investigate a possible relation between penile Doppler ultrasound examination (PDUE) parameters and efficacy of chronic therapy with tadalafil (TAD) combined with a protocol of aerobic physical activity (PA) in patients with late onset hypogonadism (LOH).

METHODS

The study evaluated 30 patients consecutively enrolled with LOH and erectile dysfunction which present contraindication to hormonal replacement therapy for concomitant prostate disease. These patients were subjected to a combined protocol with phosphodiesterase V selective inhibitors (TAD 5 mg daily) and aerobic PA.

RESULTS

After three months, we observed significant improvements in erectile function [IIEF-5, median (IQR) = 13.0 (7.0-18.0) versus 6.0 (5.0-6.75); p < 0.01] and of the main metabolic [homeostatic model assessment index, median (IQR) = 2.5 (1.62-3.37) versus 3.0 (2.0-3.75); p < 0.01; body mass index, median (IQR) = 27.0 (24.0-28.75) versus 27.5 (24.0-29.5)] and vascular parameters [peak systolic velocity, median (IQR) = 29.5 (24.25-31.0) versus 28.0 (23.0-24.25); acceleration time, median (IQR) = 114 (105.25-134.0) versus 115.0 (106.5-134.0)], assessed by PDUE.

CONCLUSION

PA in association with phosphodiesterase V inhibitors could compensate the effects of hypogonadism on erectile function and facilitate the clinical response to these drugs even in the absence of adequate serum concentrations of total testosterone.

Phosphodiesterase type-5 inhibitor use in type 2 diabetes is associated with a reduction in all-cause mortality

Objective

Experimental evidence has shown potential cardioprotective actions of phosphodiesterase type-5 inhibitors (PDE5is). We investigated whether PDE5i use in patients with type 2 diabetes, with high-attendant cardiovascular risk, was associated with altered mortality in a retrospective cohort study.

Research design and methods

Between January 2007 and May 2015, 5956 men aged 40–89 years diagnosed with type 2 diabetes before 2007 were identified from anonymised electronic health records of 42 general practices in Cheshire, UK, and were followed for 7.5 years. HRs from multivariable survival (accelerated failure time, Weibull) models were used to describe the association between on-demand PDE5i use and all-cause mortality.

Results

Compared with non-users, men who are prescribed PDE5is (n=1359) experienced lower percentage of deaths during follow-up (19.1% vs 23.8%) and lower risk of all-cause mortality (unadjusted HR=0.69 (95% CI: 0.64 to 0.79); p<0.001)). The reduction in risk of mortality (HR=0.54 (0.36 to 0.80); p=0.002) remained after adjusting for age, estimated glomerular filtration rate, smoking status, prior cerebrovascular accident (CVA) hypertension, prior myocardial infarction (MI), systolic blood pressure, use of statin, metformin, aspirin and β-blocker medication. PDE5i users had lower rates of incident MI (incidence rate ratio (0.62 (0.49 to 0.80), p<0.0001) with lower mortality (25.7% vs 40.1% deaths; age-adjusted HR=0.60 (0.54 to 0.69); p=0.001) compared with non-users within this subgroup.

Conclusion

In a population of men with type 2 diabetes, use of PDE5is was associated with lower risk of overall mortality and mortality in those with a history of acute MI.

The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review.

Comparison of High, Intermediate, and Low Frequency Shock Wave Lithotripsy for Urinary Tract Stone Disease: Systematic Review and Network Meta-Analysis

OBJECTIVES

To perform a systematic review and network meta-analysis of randomized controlled trials (RCTs) to determine the optimal shock wave lithotripsy (SWL) frequency range for treating urinary stones, i.e., high-frequency (100-120 waves/minute), intermediate-frequency (80-90 waves/minute), and low-frequency (60-70 waves/minute) lithotripsy.

MATERIALS AND METHODS

Relevant RCTs were identified from electronic databases for meta-analysis of SWL success and complication rates. Using pairwise and network meta-analyses, comparisons were made by qualitative and quantitative syntheses. Outcome variables are provided as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Thirteen articles were included in the qualitative and quantitative synthesis using pairwise and network meta-analyses. On pairwise meta-analyses, comparable inter-study heterogeneity was observed for the success rate. On network meta-analyses, the success rates of low- (OR 2.2; 95% CI 1.5-2.6) and intermediate-frequency SWL (OR 2.5; 95% CI 1.3-4.6) were higher than high-frequency SWL. Forest plots from the network meta-analysis showed no significant differences in the success rate between low-frequency SWL versus intermediate-frequency SWL (OR 0.87; 95% CI 0.51-1.7). There were no differences in complication rate across different SWL frequency ranges. By rank-probability testing, intermediate-frequency SWL was ranked highest for success rate, followed by low-frequency and high-frequency SWL. Low-frequency SWL was also ranked highest for low complication rate, with high- and intermediate-frequency SWL ranked lower.

CONCLUSIONS

Intermediate- and low-frequency SWL have better treatment outcomes than high-frequency SWL when considering both efficacy and complication.

Development of a New Radiofluorinated Quinoline Analog for PET Imaging of Phosphodiesterase 5 (PDE5) in Brain

Phosphodiesterases (PDEs) are enzymes that play a major role in cell signalling by hydrolysing the secondary messengers cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP) throughout the body and brain. Altered cyclic nucleotide-mediated signalling has been associated with a wide array of disorders, including neurodegenerative disorders. Recently, PDE5 has been shown to be involved in neurodegenerative disorders such as Alzheimer's disease, but its precise role has not been elucidated yet. To visualize and quantify the expression of this enzyme in brain, we developed a radiotracer for specific PET imaging of PDE5. A quinoline-based lead compound has been structurally modified resulting in the fluoroethoxymethyl derivative ICF24027 with high inhibitory activity towards PDE5 (IC50 = 1.86 nM). Radiolabelling with fluorine-18 was performed by a one-step nucleophilic substitution reaction using a tosylate precursor (RCY(EOB) = 12.9% ± 1.8%; RCP > 99%; SA(EOS) = 70-126 GBq/μmol). In vitro autoradiographic studies of [(18)F]ICF24027 on different mouse tissue as well as on porcine brain slices demonstrated a moderate specific binding to PDE5. In vivo studies in mice revealed that [(18)F]ICF24027 was metabolized under formation of brain penetrable radiometabolites making the radiotracer unsuitable for PET imaging of PDE5 in brain.

Erectile dysfunction and coronary heart disease

PURPOSE OF REVIEW

This narrative review discusses the associations of erectile dysfunction with coronary heart disease (CHD) morbidity and mortality, all-cause death and CHD risk factors. Treatment strategies for erectile dysfunction are also mentioned.

RECENT FINDINGS

Erectile dysfunction shares common pathways and risk factors with vascular diseases. Erectile dysfunction has been reported to independently predict CHD events, thus highlighting its role as a marker of early atherosclerosis. Erectile dysfunction prevalence may be followed by the presentation of CHD symptoms in 2-3 years, and a CHD event may occur in 3-5 years. Furthermore, erectile dysfunction has been associated with stroke, peripheral artery disease, diabetes and chronic kidney disease as well as with several CHD risk factors including hypertension, dyslipidaemia, smoking, obesity, metabolic syndrome, hyperuricaemia, arterial stiffness and obstructive sleep apnea syndrome. On the basis of these data, erectile dysfunction may be regarded as a part of polyvascular disease.

SUMMARY

Patients with erectile dysfunction are at an increased risk for CHD morbidity and/or mortality as well as for all-cause death. Clinicians should monitor patients with erectile dysfunction by assessing their vascular risk and preventing or adequately treating CHD risk factors. In this context, lifestyle interventions should be recommended in addition to drug treatment to attain better outcomes.

Erectile dysfunction

Erectile dysfunction is a multidimensional but common male sexual dysfunction that involves an alteration in any of the components of the erectile response, including organic, relational and psychological. Roles for nonendocrine (neurogenic, vasculogenic and iatrogenic) and endocrine pathways have been proposed. Owing to its strong association with metabolic syndrome and cardiovascular disease, cardiac assessment may be warranted in men with symptoms of erectile dysfunction. Minimally invasive interventions to relieve the symptoms of erectile dysfunction include lifestyle modifications, oral drugs, injected vasodilator agents and vacuum erection devices. Surgical therapies are reserved for the subset of patients who have contraindications to these nonsurgical interventions, those who experience adverse effects from (or are refractory to) medical therapy and those who also have penile fibrosis or penile vascular insufficiency. Erectile dysfunction can have deleterious effects on a man's quality of life; most patients have symptoms of depression and anxiety related to sexual performance. These symptoms, in turn, affect his partner's sexual experience and the couple's quality of life. This Primer highlights numerous aspects of erectile dysfunction, summarizes new treatment targets and ongoing preclinical studies that evaluate new pharmacotherapies, and covers the topic of regenerative medicine, which represents the future of sexual medicine.

A review of the efficacy and safety of mirodenafil in the management of erectile dysfunction

Erectile dysfunction (ED) is a common disorder that can jeopardize quality of life and the partnership of patients and their sexual partners. The advent of oral phosphodiesterase type 5 inhibitors (PDE5Is) has revolutionized a treatment for ED, and they are recognized as the first-line therapy for ED, regardless of its etiology. Mirodenafil, a second-generation PDE5I, has biochemical profiles such as high affinity for PDE5 and high selectivity for PDE5 over other PDE isoforms, compared to other existing PDE5Is such as sildenafil, vardenafil and tadalafil. Available evidence has suggested that doses of 50 and 100 mg mirodenafil effectively improve ED [with improvements in the erectile function domain of the International Index of Erectile Function (IIEF-EF) scores, positive responses to questions 2 of the Sexual Encounter Profiles (SEP2) and questions 3 of the Sexual Encounter Profiles (SEP3): 7.6-11.6 points, 27.72-38.98% and 44.20-67.33%, respectively] in a broad range of patient populations with ED of a variety of underlying etiologies, severities and ages, without any serious treatment-related adverse effects. In the treatment of diabetic ED, a traditionally difficult-to-treat population, 100 mg mirodenafil has been reported to offer favorable efficacy (with improvements in the IIEF-EF scores, and positive responses to the SEP2 and the SEP3: 9.3 points, 36.1% and 61.8%, respectively) and tolerability (mild adverse effects of less than 19.6%), which are comparable with results from clinical studies on other PDE5Is. Mirodenafil appears to be effective, safe and well tolerated in men with both ED and hypertension or lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) who are taking concomitant antihypertensive medications or α1-blockers. Furthermore, recent evidence has indicated that mirodenafil may be a potential option for chronic dosing in the treatment of ED despite its short half-life (T 1/2). Most of the available clinical studies have reported that adverse effects (up to 53.7%) caused by 50 and 100 mg mirodenafil are mild or moderate in severity, with headache (1.8-14.8%) and flushing (6.7-24.1%) being the most common. Due to the pharmacodynamic profiles of mirodenafil, its tolerability is expected to be somewhat better than those of the other PDE5Is. However, further well designed studies with larger cohorts of different ethnicities, flexible dosing schedules and long-term follow up are necessary to confirm the favorable efficacy and tolerability profiles of mirodenafil for the treatment of ED.

Tadalafil 5 mg once daily for the treatment of erectile dysfunction during a 6-month observational study (EDATE): impact of patient characteristics and comorbidities

BACKGROUND

To explore the impact of patient-characteristics and relevant comorbidities on treatment continuation rates, effectiveness, and satisfaction in patients with erectile dysfunction (ED) who started or switched to tadalafil 5 mg once daily (TAD-OaD) at baseline.

METHODS

In the EDATE observational study, phosphodiesterase-type-5 (PDE5)-inhibitor pretreated or naïve ED patients who started or switched to TAD-OaD were prospectively followed for 6 months. Time to discontinuation of TAD-OaD was estimated using the Kaplan-Meier product-limit method at Months 2, 4, and 6 in subgroups stratified by age (18 - 65 years and >65 years), PDE5-inhibitor pretreatment, ED-severity (mild, moderate, severe), and presence or absence of relevant comorbidities (BPH, diabetes, CVD, hypertension, dyslipidemia). LSmean change from baseline in International Index of Erectile Function (IIEF) and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) scores and associated 95 % CIs were assessed using a mixed-model for repeated measures. Visit, ED etiology, and subgroups were included as fixed-effects.

RESULTS

Overall, 778 patients received prescriptions for initiating or switching to TAD-OaD at baseline. At Month 2, >90 % of patients remained on TAD-OaD, except those aged >65 years (86.7 %) and patients with severe ED (89.0 %). More than 80 % of patients in all subgroups, except those aged >65 years (75.0 %), continued TAD-OaD at Month 6. There was a significant LSmean negative effect on IIEF- EF domain-score improvement for BPH (LSmean effect [95 % CI]: -2.77 [-4.98, -0.55], p = 0.014), previous PDE5-inhibitor treatment (-2.13 [-3.33,-0.94], p < 0.001), and mild vs moderate ED (-2.00 [-3.54,-0.46], p = 0.011); the latter possibly linked with a bigger treatment-effect in those with more severe ED at baseline. The LSmean effect on change in IIEF-EF was significantly positive for diabetes (2.28 [0.64,3.92], p = 0.007), most likely because those with diabetes had more severe ED at baseline. For all other parameters, no statistically significant LSmean effects in IIEF-EF changes were observed. No comorbidity or baseline-characteristic except age (18 - 65 years vs >65 years: 11.25 [2.96,19.54], p = 0.008) affected changes in EDITS.

CONCLUSIONS

Under routine clinical conditions, treatment continuation rate or satisfaction does not seem to be significantly affected by the presence of comorbidities in men who choose ED-treatment with TAD-OaD. The magnitude of treatment effectiveness was affected by certain baseline characteristics and comorbid conditions.

TRIAL REGISTRATION

The study (H6D-EW-LVIU) is registered in the German VfA Registry of Non-Interventional Studies (Verband Forschender Arzneimittelhersteller) since 06 December 2011; available at: http://www.vfa.de/de/arzneimittel-forschung/datenbanken-zu-arzneimitteln/nisdb/nis-details/_741 .

Comparative effectiveness and tolerance of treatments for Helicobacter pylori: systematic review and network meta-analysis

OBJECTIVE

To determine the most efficacious treatment for eradication of Helicobacter pylori with the lowest likelihood of some common adverse events among pre-recommended and newer treatment regimens.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Cochrane Library, PubMed, and Embase without language or date restrictions.

STUDY SELECTION

Full text reports of randomised controlled trials that compared different eradication treatments for H pylori among adults.

RESULTS

Of the 15,565 studies identified, 143 were eligible and included. Data on 14 kinds of treatments were available. Of 91 possible comparisons for the efficacy outcome, 34 were compared directly and the following treatments performed better: seven days of concomitant treatment (proton pump inhibitor and three kinds of antibiotics administered together), 10 or 14 days of concomitant treatment, 10 or 14 days of probiotic supplemented triple treatment (standard triple treatment which is probiotic supplemented), 10 or 14 days of levofloxacin based triple treatment (proton pump inhibitor, levofloxacin, and antibiotic administered together), 14 days of hybrid treatment (proton pump inhibitor and amoxicillin used for seven days, followed by a proton pump inhibitor, amoxicillin, clarithromycin, and 5-nitroimidazole for another seven days), and 10 or 14 days of sequential treatment (five or seven days of a proton pump inhibitor plus amoxicillin, followed by five or seven additional days of a proton pump inhibitor plus clarithromycin and 5-nitroimidazole or amoxicillin). In terms of tolerance, all treatments were considered tolerable, but seven days of probiotic supplemented triple treatment and seven days of levofloxacin based triple treatment ranked best in terms of the proportion of adverse events reported.

CONCLUSION

Comparison of different eradication treatments for H pylori showed that concomitant treatments, 10 or 14 days of probiotic supplemented triple treatment, 10 or 14 days of levofloxacin based triple treatment, 14 days of hybrid treatment, and 10 or 14 days of sequential treatment might be better alternatives for the eradication of H pylori.

Association Between Dosage Frequency and the Treatment Outcomes of Sildenafil in Young and Middle-aged Men With Erectile Dysfunction: A Chinese, Multicenter, Observational Study

OBJECTIVE

To evaluate the correlation between the dosage frequency of sildenafil and its treatment outcomes in men with erectile dysfunction (ED).

METHODS

Data were from a 4-week, multicenter, observational study of men (1699), between 18 and 60 years of age, with a clinical diagnosis of ED defined as the Sexual Health Inventory for Men (SHIM) score ≤21. The erectile function and quality of sexual life were evaluated at the baseline and the endpoint of sildenafil treatment (after 4 weeks) by using SHIM, Self-Esteem and Relationship Questionnaire, 36-Item Short Form Health Survey, Erection Hardness Score, and the global efficacy question.

RESULTS

Nine hundred thirty-five patients were enrolled in the ≤1 weekly, 573 in the 2-3 weekly, and 158 in the 4-7 weekly dosage frequency cohorts. After 4 weeks of treatment, a higher dosage frequency of sildenafil was associated with a better SHIM, Self-Esteem and Relationship Questionnaire, and 36-Item Short Form Health Survey score improvement (all P <.0001). Hyperlipidemia is a poor prognostic factor (odds ratio, 3.59; P = .04), whereas hypertension (odds ratio, 0.25; P <.01) and coronary heart disease (odds ratio, 0.56; P = .05) are sensitive to sildenafil treatment.

CONCLUSION

Higher dosage frequency of sildenafil is associated with a better improvement of sexual function and quality of life of men with ED, and the concomitant treatment of hyperlipidemia is recommended.

Comparative Effectiveness and Safety of Monodrug Therapies for Lower Urinary Tract Symptoms Associated With Benign Prostatic Hyperplasia: A Network Meta-analysis

A wide array of drugs are available for the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), but the evidence for the comparative effectiveness is controversial.The objective of this study is to evaluate the comparative effectiveness and safety of monodrug therapies for BPH.Data sources are MEDLINE, EMBASE, and the Cochrane Library.We included randomized controlled trials that compared α-blockers, 5-alpha reductase inhibitors (5ARIs), muscarinic receptor antagonists (MRAs), phosphodiesterase-5 inhibitor (PDE5-Is), or placebo for the treatment of BPH.Comparative effectiveness and safety were pooled by both traditional meta-analysis and network meta-analysis. Summary effect size was calculated as mean difference (MD) and relative risk (RR), together with the 95% confidence intervals (CIs).This study included 58,548 participants from 124 trials in total. When compared with placebo, α-blockers, 5ARIs, and PDE5-Is reduced International Prostate Symptom Score (IPSS) by -1.35 to -3.67 points and increased peak urinary flow rate (PUF) by -0.02 to 1.95 mL/s, with doxazosin (IPSS: MD, -3.67[-4.33 to -3.02]; PUF: MD, 1.95[1.61 to 2.30]) and terazosin (IPSS: MD, -3.37 [-4.24 to -2.50]; PUF: MD, 1.21[0.74 to 1.66]) showing the greatest improvement. The improvement in the IPSS was comparable among tamsulosin, alfuzosin, naftopidil, silodosin, dutasteride, sildenafil, vardenafil, and tadalafil. The incidence of total adverse events and withdraws due to adverse events were generally comparable among various agents.In conclusion, α-blockers, 5ARIs, and PDE5-Is are effective for BPH, with doxazosin and terazosin appearing to be the most effective agents. Drug therapies for BPH are generally safe and well-tolerated, with no major difference regarding the overall safety profile.

The beneficial effect of alpha-blockers for ureteral stent-related discomfort: systematic review and network meta-analysis for alfuzosin versus tamsulosin versus placebo

Background

This study was carried out a network meta-analysis of evidence from randomized controlled trials (RCTs) to evaluate stent-related discomfort in patients with alfuzosin or tamsulosin versus placebo.

Methods

Relevant RCTs were identified from electronic databases. The proceedings of appropriate meetings were also searched. Seven articles on the basis of RCTs were included in our meta-analysis. Using pairwise and network meta-analyses, comparisons were made by qualitative and quantitative syntheses. Evaluation was performed with the Ureteric Stent Symptoms Questionnaire to assess the urinary symptom score (USS) and body pain score (BPS).

Results

One of the seven RCTs was at moderate risk of bias for all quality criteria; two studies had a high risk of bias. In the network meta-analysis, both alfuzosin (mean difference [MD];−4.85, 95 % confidence interval [CI];−8.53–−1.33) and tamsulosin (MD;−8.84, 95 % CI;−13.08–−4.31) showed lower scores compared with placebo; however, the difference in USS for alfuzosin versus tamsulosin was not significant (MD; 3.99, 95 % CI;−1.23–9.04). Alfuzosin (MD;−5.71, 95 % CI;−11.32–−0.52) and tamsulosin (MD;−7.77, 95 % CI;−13.68–−2.14) showed lower scores for BPS compared with placebo; however, the MD between alfuzosin and tamsulosin was not significant (MD; 2.12, 95 % CI;−4.62–8.72). In the rank-probability test, tamsulosin ranked highest for USS and BPS, and alfuzosin was second.

Conclusion

The alpha-blockers significantly decreased USS and BPS in comparison with placebo. Tamsulosin might be more effective than alfuzosin.

Risk-benefit assessment of oral phosphodiesterase type 5 inhibitors for treatment of erectile dysfunction: a multiple criteria decision analysis

BACKGROUND

Erectile dysfunction (ED) is a common male sexual disorder worldwide. Three oral phosphodiesterase type 5 inhibitors (PDE5Is) - sildenafil, tadalafil and vardenafil - are available for treatment of ED. This study quantitatively evaluated the therapeutic efficacy and safety of these medications to assist treatment decision making.

METHODS

We used multiple criteria decision analysis (MCDA) to assess the totality of risk-benefit of PDE5Is. We created two models: (i) the overall model included 'overall improvement in erections' and 'any adverse events' and (ii) the detailed model included 'erectile function domain', 'ability for sexual intercourse', 'duration of erection last', 'serious adverse events', 'headache', 'flushing' and 'dyspepsia'. We calculated a synthetic utility for each drug accounting for all of its benefits and risks.

RESULTS

Considering the overall risk-benefit, vardenafil had the highest synthetic utility among three medications; in the order of synthetic utilities: vardenafil (0.568), tadalafil (0.478) and sildenafil (0.437). However, when specific risk and benefit criteria were assessed, tadalafil had the highest synthetic utility (0.602) according to the conjoint evaluation (synthetic utility for vardenafil is 0.491 and sildenafil is 0.442, respectively). The sensitivity analysis based on the uncertainties of weight on risks of any adverse events (including serious adverse events and headache) suggested our results were robust.

CONCLUSIONS

This study provides a useful approach that comprehensively and systematically assesses and compares the risk-benefit of several treatment alternatives. Our study not only rank treatment alternatives by synthetic utilities based on the risk-benefit balance but also compare specific risk and benefit criteria between these medicines. Our results provide valuable evidence that can guide clinicians and patients in making treatment decisions.

Phosphodiesterase 5 inhibitors for the treatment of erectile dysfunction: a trade-off network meta-analysis

CONTEXT

Erectile dysfunction (ED) is a major health care problem worldwide and phosphodiesterase 5 inhibitors (PDE5Is) are the pharmacological treatment of choice. However, the optimal PDE5I for ED treatment is not known.

OBJECTIVE

To investigate trade-offs between efficacy and adverse events for various PDE5Is in treating ED.

EVIDENCE ACQUISITION

A review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. Medline, Scopus, reference lists of relevant articles, and systematic reviews were searched. Eligible studies were randomized controlled trials comparing at least one PDE5I for treating ED with placebo or another PDE5I.

EVIDENCE SYNTHESIS

We included 82 trials (47 626 patients) for efficacy analysis and 72 trials (20 325 patients) for adverse event analysis. In the trade-off analysis of starting dosages, sildenafil 50mg had the greatest efficacy but also had the highest rate of overall adverse events. Tadalafil 10mg had intermediate efficacy but had the lowest overall rate of all adverse events. Vardenafil 10mg and avanafil 100mg had similar overall adverse events than sildenafil 50mg but a markedly lower global efficacy. Udenafil 100mg had similar global efficacy to that of tadalafil 10mg but its overall adverse event rates were higher.

CONCLUSIONS

This is the first trade-off analysis of the different PDE5Is currently available. For individuals who prioritize high efficacy, sildenafil 50mg appears to be the treatment of choice. Men wishing to optimize tolerability should take tadalafil 10mg or switch to udenafil 100mg in the case of insufficient efficacy.

PATIENT SUMMARY

For patients with erectile dysfunction who wish to prioritize high efficacy, sildenafil 50mg appears to be the treatment of choice. Men who wish to optimize tolerability should take tadalafil 10mg or switch to udenafil 100mg in the case of insufficient efficacy.

Efficacy and safety of phosphodiesterase type 5 (PDE5) inhibitors in treating erectile dysfunction after bilateral nerve-sparing radical prostatectomy

We carried out a systematic review and meta-analysis to assess the efficacy and safety of phosphodiesterase type 5 (PDE5) inhibitors for treating erectile dysfunction (ED) after bilateral nerve-sparing radical prostatectomy (BNSRP). A literature review was performed to identify all published randomised double-blind, placebo-controlled trials of PDE5 inhibitors for the treatment of ED after BNSRP. The search included the following databases: MEDLINE, EMBASE and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated. Six publications involving a total of 1678 patients were used in the analysis, including six RCTs that compared PDE5 inhibitors (tadalafil, sildenafil, avanafil and vardenafil) with placebo. Co-primary efficacy end points: International Index of Erectile Function-Erectile Function (IIEF-EF) domain score [the standardised mean difference (SMD) = 4.04, 95% confidence interval (CI) = 2.87-5.22, P < 0.00001]; successful vaginal penetration (SEP2) [the odds ratio (OR) = 14.87, 95%CI = 4.57-48.37, P < 0.00001]; and successful intercourse (SEP3) (OR = 47, 95%CI = 3-13.98, P < 0.00001) indicated that PDE5 inhibitors was more effective than the placebo. Specific adverse events with PDE5 inhibitors included headache (12.08%), dyspepsia (6.76%) and flushing (6.52%), which were significantly less likely to occur with placebo. This meta-analysis indicates that PDE5 inhibitors to be an effective and well-tolerated treatment for ED after BNSRP.

Does alprostadil cream hit the spot?

Alprostadil, a prostaglandin, has been marketed for many years as a urethral stick and an intracavernous injection for the treatment of erectile dysfunction.(1) It is now available in the form of a cream (Vitaros-Takeda). Adverts for the product declare: "Sex with no pills, pellets or needles. Spot on." In this article, we consider the evidence for alprostadil cream, and its place in the management of erectile dysfunction.

An open-label, multicenter, randomized, crossover study comparing sildenafil citrate and tadalafil for treating erectile dysfunction in Chinese men naïve to phosphodiesterase 5 inhibitor therapy

The study was to compare treatment preference, efficacy, and tolerability of sildenafil citrate (sildenafil) and tadalafil for treating erectile dysfunction (ED) in Chinese men naοve to phosphodiesterase 5 (PDE5) inhibitor therapies. This multicenter, randomized, open-label, crossover study evaluated whether Chinese men with ED preferred 20-mg tadalafil or 100-mg sildenafil. After a 4 weeks baseline assessment, 383 eligible patients were randomized to sequential 20-mg tadalafil per 100-mg sildenafil or vice versa for 8 weeks respectively and then chose which treatment they preferred to take during the 8 weeks extension. Primary efficacy was measured by Question 1 of the PDE5 Inhibitor Treatment Preference Questionnaire (PITPQ). Secondary efficacy was analyzed by PITPQ Question 2, the International Index of Erectile Function (IIEF) erectile function (EF) domain, sexual encounter profile (SEP) Questions 2 and 3, and the Drug Attributes Questionnaire. Three hundred and fifty men (91%) completed the randomized treatment phase. Two hundred and forty-two per 350 (69.1%) patients preferred 20-mg tadalafil, and 108/350 (30.9%) preferred 100-mg sildenafil (P < 0.001) as their treatment in the 8 weeks extension. Ninety-two per 242 (38%) patients strongly preferred tadalafil and 37/108 (34.3%) strongly the preferred sildenafil. The SEP2 (penetration), SEP3 (successful intercourse), and IIEF-EF domain scores were improved in both tadalafil and sildenafil treatment groups. For patients who preferred tadalafil, getting an erection long after taking the medication was the most reported reason for tadalafil preference. The only treatment-emergent adverse event reported by > 2% of men was headache. After tadalafil and sildenafil treatments, more Chinese men with ED naοve to PDE5 inhibitor preferred tadalafil. Both sildenafil and tadalafil treatments were effective and safe.

A comparison of the available phosphodiesterase-5 inhibitors in the treatment of erectile dysfunction: a focus on avanafil

BACKGROUND

Numerous pathways can lead to erectile dysfunction (ED) in patients, with some patients having multiple causes. Regardless of the etiology, ED has been successfully treated in many patients with the advent of oral phosphodiesterase-5 inhibitors (PDE5Is). With the release of avanafil, there are currently four PDE5I options available, and choosing between them should be based on patient-specific considerations and preferences.

OBJECTIVE

To review the treatment of ED with PDE5Is, taking into account the effectiveness, safety, and patient satisfaction of these agents, as well as avanafil's place in therapy.

METHODS

A PubMed search was completed to find articles published in English studying patient satisfaction and adherence to ED medication. Additional searches looked specifically for any data regarding the use of avanafil.

RESULTS

ED is effectively treated in most patients with PDE5Is, with the most common side effects from the medications being headache, flushing, and visual disturbances. Patients have identified many different factors, such as efficacy, side effects, duration of action, and daily use, in determining overall satisfaction and the right medication for them. While avanafil does not have any patient satisfaction trials to date, it has been proven to be a safe and effective treatment for ED with possibly the fastest onset of action and fewer visual disturbances than its competitors.

CONCLUSION

Avanafil along with the other PDE5Is has shown to be a safe and effective oral treatment for ED, with avanafil's possible place in therapy for patients who want an on-demand option or as an alternative in patients who experience visual disturbances with the other agents.

Eight challenges faced by general practitioners caring for patients after an acute coronary syndrome

The general practitioner is essential in the management of the patient who has recently been discharged from hospital following an acute coronary syndrome (ACS), particularly as duration of hospital stay is shorter than in previous decades. GPs caring for patients after an ACS face numerous challenges. Often, the first of these is insufficient or delayed documentation from the discharging hospital, although electronic discharge summaries are alleviating this problem. Post-ACS patients often have comorbidities, and GPs play a key role in managing these. Patients taking dual antiplatelet therapy who need surgery, and post-ACS patients with atrial fibrillation, require particular care from GPs. Patients will often approach their GP for advice on the safety of other drugs, such as smoking cessation medication, and phosphodiesterase type 5 inhibitors for erectile dysfunction. For patients complaining of persistent lethargy after an ACS, GPs must consider several differential diagnoses, including depression, hypotension, hypovolaemia, and side effects of β-blockers. GPs play an important ongoing role in ensuring that target cholesterol levels are reached with statin therapy; this includes ensuring long-term adherence. They may also need to advise patients who want to stop statin therapy, usually due to perceived side effects. Many of these challenges can be met with improved and respectful communication between the hospital, the treating cardiologist and the GP. The patient needs to be closely involved in the decision-making process, particularly when balancing the risks of bleeding versus thrombosis.

Nebivolol potentiates the efficacy of PDE5 inhibitors to relax corpus cavernosum and penile arteries from diabetic patients by enhancing the NO/cGMP pathway

INTRODUCTION

The efficacy of oral pharmacotherapy for erectile dysfunction (ED) (i.e., type 5 phosphodiesterase[PDE5] inhibitors) is significantly reduced in diabetic patients. Nebivolol is a selective β1-blocker used for treatinghy pertension that has been shown to increase the efficacy of sildenafil to reverse ED in diabetic rats.

AIM

To evaluate the effects of nebivolol on the efficacy of the PDE5 inhibitors, sildenafil, tadalafil, and vardenafil to relax human corpus cavernosum (HCC) and vasodilate human penile resistance arteries (HPRA) from diabetic patients with ED (DMED). The influence of nebivolol on the capacity of these three PDE5 inhibitors to stimulate cyclic guanosine monophosphate (cGMP) production in HCC was also evaluated.

METHODS

HCC and HPRA were obtained from organ donors without ED (NEND; n = 18) or patients with diabetes undergoing penile prosthesis implantation (DMED; n = 19). Relaxations of HCC strips and HPRA to sildenafil,tadalafil, and vardenafil were evaluated in organ chambers and wire myographs. cGMP content in HCC was determined by ether extraction and quantification by ELISA.

MAIN OUTCOME MEASURES

Effects of nebivolol on PDE5 inhibitor-induced relaxation of HCC, vasodilation ofHPRA and cGMP accumulation in HCC.

RESULTS

Treatment with nebivolol (1 μM) significantly potentiated sildenafil-, tadalafil- and vardenafil-induced relaxations of HCC and vasodilations of HPRA from both NEND and DMED. Enhancement of relaxant capacity by nebivolol resulted in reversion of the impairment of PDE5 inhibition-induced responses in DMED and it was accompanied by enhancing the ability of PDE5 inhibitors to increase cGMP in HCC restoring reduced cGMP levelsin HCC from DMED.

CONCLUSIONS

Nebivolol potentiated the capacity of PDE5 inhibitors to relax vascular structures of erectile tissue from diabetic patients by enhancing the nitric oxide (NO)/cGMP pathway in these tissues. These effects suggest a potential therapeutic utility of nebivolol as an adjunct to PDE5 inhibitors for the treatment of ED associated with diabetes.

Cyclic nucleotide phosphodiesterases: important signaling modulators and therapeutic targets

By catalyzing hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), cyclic nucleotide phosphodiesterases are critical regulators of their intracellular concentrations and their biological effects. As these intracellular second messengers control many cellular homeostatic processes, dysregulation of their signals and signaling pathways initiate or modulate pathophysiological pathways related to various disease states, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication, chronic obstructive pulmonary disease, and psoriasis. Alterations in expression of PDEs and PDE-gene mutations (especially mutations in PDE6, PDE8B, PDE11A, and PDE4) have been implicated in various diseases and cancer pathologies. PDEs also play important role in formation and function of multimolecular signaling/regulatory complexes, called signalosomes. At specific intracellular locations, individual PDEs, together with pathway-specific signaling molecules, regulators, and effectors, are incorporated into specific signalosomes, where they facilitate and regulate compartmentalization of cyclic nucleotide signaling pathways and specific cellular functions. Currently, only a limited number of PDE inhibitors (PDE3, PDE4, PDE5 inhibitors) are used in clinical practice. Future paths to novel drug discovery include the crystal structure-based design approach, which has resulted in generation of more effective family-selective inhibitors, as well as burgeoning development of strategies to alter compartmentalized cyclic nucleotide signaling pathways by selectively targeting individual PDEs and their signalosome partners.