Two Birds with One Stone: Regular Use of PDE5 Inhibitors for Treating Male Patients with Erectile Dysfunction and Cardiovascular Diseases

Cardiac Effects of Phosphodiesterase-5 Inhibitors: Efficacy and Safety

The coexistence of cardiovascular disease and erectile dysfunction is widespread, possibly owing to underlying endothelial dysfunction in both diseases. Millions of patients with cardiovascular disease are prescribed phosphodiesterase-5 (PDE5) inhibitors for the management of erectile dysfunction. Although the role of PDE5 inhibitors in erectile dysfunction therapy is well established, their effects on the cardiovascular system are unclear. Preclinical studies investigating the effect of PDE5 inhibitors on ischemia-reperfusion injury, pressure overload-induced hypertrophy, and chemotoxicity suggested a possible clinical role for each of these medications; however, attempts to translate these findings to the bedside have resulted in mixed outcomes. In this review, we explore the biologic preclinical effects of PDE5 inhibitors in mediating cardioprotection. We then examine clinical trials investigating PDE5 inhibition in patients with heart failure, coronary artery disease, and ventricular arrhythmias and discuss why the studies likely have yet to show positive results and efficacy with PDE5 inhibition despite no safety concerns.

Treating diabetes with combination of phosphodiesterase 5 inhibitors and hydroxychloroquine-a possible prevention strategy for COVID-19?

Type 2 diabetes (T2D) is one of the major risk factors for developing cardiovascular disease and the resultant devastating morbidity and mortality. The key features of T2D are hyperglycemia, hyperlipidemia, insulin resistance, and impaired insulin secretion. Patients with diabetes and myocardial infarction have worse prognosis than those without T2D. Moreover, obesity and T2D are recognized risk factors in developing severe form of COVID-19 with higher mortality rate. The current lines of drug therapy are insufficient to control T2D and its serious cardiovascular complications. Phosphodiesterase 5 (PDE5) is a cGMP specific enzyme, which is the target of erectile dysfunction drugs including sildenafil, vardenafil, and tadalafil. Cardioprotective effects of PDE5 inhibitors against ischemia/reperfusion (I/R) injury were reported in normal and diabetic animals. Hydroxychloroquine (HCQ) is a widely used antimalarial and anti-inflammatory drug and its hyperglycemia-controlling effect in diabetic patients is also under investigation. This review provides our perspective of a potential use of combination therapy of PDE5 inhibitor with HCQ to reduce cardiovascular risk factors and myocardial I/R injury in T2D. We previously observed that diabetic mice treated with tadalafil and HCQ had significantly reduced fasting blood glucose and lipid levels, increased plasma insulin and insulin-like growth factor-1 levels, and improved insulin sensitivity, along with smaller myocardial infarct size following I/R. The combination treatment activated Akt/mTOR cellular survival pathway, which was likely responsible for the salutary effects. Therefore, pretreatment with PDE5 inhibitor and HCQ may be a potentially useful therapy not only for controlling T2D but also reducing the rate and severity of COVID-19 infection in the vulnerable population of diabetics.

Isolation, bioassay and 3D-QSAR analysis of 8-isopentenyl flavonoids from Epimedium sagittatum maxim. as PDE5A inhibitors

BACKGROUND

As known, inhibition of phosphodiesterase 5 (PDE5) has the therapeutic effect on male erectile dysfunction (ED), and the processed folium of Epimedium sagittatum Maxim. (PFES) characterized by 8-isopentenyl flavonoids is a famous herb for treating ED. However, the main flavonoids inhibitory activities, structure-activity relationship (SAR) and signaling pathway have been not systematically studied so that its pharmacodynamic mechanism is unclear.

METHODS

We aimed to initially reveal the PFES efficacy mechanism for treating ED. For the first time, 6 main 8-isopentenyl flavonoids (1-6) from PFES were isolated and identified. Then based on HPLC detection, we proposed a novel method to screen inhibitors among them. We further analyze the three-dimensional quantitative structure-activity relationship (3D-QSAR) for those inhibitors.

RESULTS

The results were verified by cellular effects of the screened flavonoids. Among 6 compounds, Icariin: (1), 2-O''rhamnosylicaridide II (2) and Baohuoside I (3) were identified with significant activities (IC₅₀ = 8.275, 3.233, 5.473 μM). Then 3D-QSAR studies showed that the replacement of C8 with bulky steric groups as isopentenyl, C3 with positive charge groups and C4' with a hydrogen bond acceptor substituent could increase inhibitory effects. In contrast, the substitution of C7 with bulky steric groups or hydrophilic groups tended to decrease the efficacies. And compounds 1, 2, 3 could increase cGMP level and decrease cytoplasmic Ca²⁺ of rat corpus cavernosum smooth muscle cells (CCSMCs)by activating PKG.

CONCLUSION

8-isopentenyl flavonoids could be the main pharmacodynamic substances of PFES in the treatment for ED, and some had significant PDE5A1 inhibitory activities so as to activate cGMP/PKG/Ca²⁺ signaling pathway in CCSMCs, that was related to the substituents at the key sites such as C8, C3, C4' and C7 in the characteristic compounds.

Reno-protective effects of Phosphodiesterase 5 inhibitors

The kidneys are vital organs that play an important role in removing waste materials from the blood, electrolyte balance, blood pressure regulation, and red blood cell genesis. Kidney disease can be caused by various factors, including diabetes, ischemia/reperfusion injury, and nephrotoxic agents. Inflammation and oxidative stress play a key role in the progression and pathogenesis of kidney diseases. Acute kidney injury (AKI) and chronic kidney disease (CKD) are important health problems worldwide, as they are associated with a long-term hospital stay, and increased morbidity and mortality in high-risk patients. Current standard therapeutic options are not sufficient to delay or stop the loss of kidney function. Therefore, it is necessary to develop new therapeutic options. Phosphodiesterase 5 inhibitors (PDE5Is) are a currently available class of drugs that are used to treat erectile dysfunction and pulmonary hypertension in humans. However, recent evidence suggests that PDE5Is have beneficial renoprotective effects via a variety of mechanisms. In this review, the benefits of PDE5 inhibitors in clinical conditions associated with kidney disease, such as diabetic nephropathy, ischemia-reperfusion injury, and acute and chronic kidney injury, are summarized.

Anti-infection mechanism of phosphodiesterase-5 inhibitors and their roles in coronavirus disease 2019 (Review)

Coronavirus disease 2019 (COVID-19) has a variety of impacts on the human body. Severe acute respiratory syndrome coronavirus 2 is the pathogen that causes COVID-19. It invades human tissues through the receptor angiotensin-converting enzyme 2, resulting in an imbalance in the angiotensin II (AngII) level and upregulation of renin-angiotensin system/AngII pathway activity. Furthermore, the binding of AngII to its receptor leads to vasoconstriction, endothelial injury and intravascular thrombosis. In addition, COVID-19 may have adverse effects on male reproductive organs and a marked impact on male reproductive health. Phosphodiesterase-5 inhibitors (PDE5Is) may improve vascular endothelial function, promote testicular and systemic blood circulation and testosterone secretion and enhance epididymal function, as well as sperm maturation and capacitation. PDE5Is may also be of use in the treatment of infectious diseases by enhancing immunity and anti-inflammatory responses and improving vascular endothelial function. Based on the pharmacological mechanism of PDE5Is, they are of unique value in the fight against infectious diseases and may be effective in combination with direct antiviral drugs. The anti-infection mechanisms of PDE5Is and their roles in COVID-19 were reviewed in the present study.

Vardenafil in the Treatment of Male Erectile Dysfunction: A Systematic Review and Meta-Analysis

INTRODUCTION

We carried out this systemic review and meta-analysis of relevant randomized controlled trials to determine different dosage regimens of vardenafil in the treatment of male erectile dysfunction (ED).

METHODS

Using appropriate keywords, we searched PubMed, the Cochrane Library, and Embase for relevant literature before March 2020. We evaluated odds ratio (OR), weighted mean difference (WMD), and 95% confidence interval (95% CI) to assess the results of each study.

RESULTS

We included 14 studies with a total of 3221 patients. Compared with the placebo, vardenafil significantly increased International Erectile Function Index (IIEF) overall satisfaction (WMD 3.37, 95% CI 2.02-4.71), IIEF-erectile function (WMD 7.93, 95% CI 6.00-9.85), IIEF sexual desire (WMD 0.79, 95% CI 0.24-1.35), IIEF intercourse satisfaction (WMD 5.24, 95% CI 3.35-7.13), IIEF orgasmic function (WMD 3.81, 95% CI 2.26-5.35), Sexual Encounter Profile (SEP) Q2 (WMD 26.36, 95% CI 22.95-29.77), and SEP Q3 (WMD 35.18, 95% CI 31.89-38.48).

CONCLUSIONS

Vardenafil demonstrated significant efficacy in the treatment of ED, but the optimal dose and course of vardenafil remain to be established.

Evaluation of the Psychological Status, Infertility-Associated Factors, and Erectile Function in Patients with Timely Ovulatory Intercourse Failure in China: Evidence from a Cross-Sectional Study

Results

A total of 1128 patients were enrolled, and 264 of them (23.40%) suffered from TOIF. TOIF was positively associated with smoking, drinking, hypertension, diabetes, anxiety, unknown cause of infertility, lower semen concentration, lower frequency of intercourse, and decreased erectile function. The total IIEF-15 scores, erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction were significantly decreased in patients with TOIF.

Conclusion

TOIF is associated with lower semen concentration, anxiety, and other comorbidities such as hypertension and diabetes. Clinicians are required to focus on these associated factors in addition to improve the erectile function.

Erectile dysfunction and cardiovascular risk: a review of current findings

Introduction: A large body of evidence has clearly documented that erectile dysfunction (ED) represents not only a complication of cardiovascular (CV) diseases (CVD) but often an early sign of forthcoming CVD.Areas covered: All the available data from meta-analyses evaluating the association between ED and CV risk were collected and discussed. Similarly, all available meta-analyses investigating the significance of ED as a possible early marker for major adverse cardiovascular events (MACE) were analyzed. In addition, data originally obtained in a Florence cohort, dealing with a large series of patients seeking medical care for sexual dysfunction, will be also reported.Expert opinion: Available evidence indicates that ED represents a risk factor of CV mortality and morbidity. Not only conventional CV risk factors but also unconventional ones, derived from a perturbation of the relational and intrapsychic domains of ED, might play a possible role in CV risk stratification of ED subjects. Finally, penile doppler ultrasound can give important information on CV risk, especially in younger and low risk subjects. The presence of ED should become an opportunity - for the patient and for the physician - to screen for the presence of comorbidities improving not only sexual health but, more importantly, men's overall health.

Should All Men with Type 2 Diabetes Be Routinely Prescribed a Phosphodiesterase Type 5 Inhibitor?

Important health problems in men such as type 2 diabetes (T2DM), insulin resistance, erectile dysfunction, benign prostatic hyperplasia and depression have been shown to have to share common pathological processes, such as endothelial dysfunction and inflammation. This paper discusses the role of phosphodiesterase type 5 (PDE5) inhibitors, through beneficial effects on endothelial function and mediators of chronic inflammation and the possibility to treat or preventing these common conditions. We explore possible barriers to this approach, namely the lack of multiple product licences to treat each of these conditions and how these can be overcome by involving the patient in personalised decisions. We also discuss how opportunities are lost by patients with multiple medical conditions being referred to specialists, primarily interested in one specific problem, with little motivation to treat or prevent conditions outside their remit. We explore how these problems might be related to time and financial restraints or simply a lack of awareness of evidence published in journals related to other specialities. As specialists, we often pride ourselves on providing "personalised" or "patient centred" care, but we can only truly be doing so if we assess the specific needs of the patient across a range of conditions. As part of personalised care in T2DM, we routinely prescribe statins, angiotensin converting enzyme inhibitors and metformin, often with poor compliance. In this paper we explore whether the licensed daily PDE5 inhibitor tadalafil should be added routinely to this list as it will potentially improve and prevent bothersome symptoms and improve compliance with other medications.

STAT3 and STAT5 Targeting for Simultaneous Management of Melanoma and Autoimmune Diseases

Melanoma is a skin cancer which can become metastatic, drug-refractory, and lethal if managed late or inappropriately. An increasing number of melanoma patients exhibits autoimmune diseases, either as pre-existing conditions or as sequelae of immune-based anti-melanoma therapies, which complicate patient management and raise the need for more personalized treatments. STAT3 and/or STAT5 cascades are commonly activated during melanoma progression and mediate the metastatic effects of key oncogenic factors. Deactivation of these cascades enhances antitumor-immune responses, is efficient against metastatic melanoma in the preclinical setting and emerges as a promising targeting strategy, especially for patients resistant to immunotherapies. In the light of the recent realization that cancer and autoimmune diseases share common mechanisms of immune dysregulation, we suggest that the systemic delivery of STAT3 or STAT5 inhibitors could simultaneously target both, melanoma and associated autoimmune diseases, thereby decreasing the overall disease burden and improving quality of life of this patient subpopulation. Herein, we review the recent advances of STAT3 and STAT5 targeting in melanoma, explore which autoimmune diseases are causatively linked to STAT3 and/or STAT5 signaling, and propose that these patients may particularly benefit from treatment with STAT3/STAT5 inhibitors.