Cardiac Effects of Phosphodiesterase-5 Inhibitors: Efficacy and Safety

The Acid Sphingomyelinase Inhibitor Amitriptyline Ameliorates TNF-α-Induced Endothelial Dysfunction

PURPOSE

Inflammation associated endothelial cell (EC) dysfunction is key to atherosclerotic disease. Recent studies have demonstrated a protective role of amitriptyline in cardiomyocytes induced by hypoxia/reoxygenation. However, the mechanism by which amitriptyline regulates the inflammatory reaction in ECs remains unknown. Thus, the aim of this study was to investigate whether amitriptyline protects against inflammation in TNF-α-treated ECs.

METHODS

HUVECs were incubated with amitriptyline (2.5 μM) or TNF-α (20 ng/ml) for 24 h. EdU, tube formation, transwell, DHE fluorescence staining, and monocyte adhesion assays were performed to investigate endothelial function. Thoracic aortas were isolated from mice, and vascular tone was measured with a wire myograph system. The levels of ICAM-1, VCAM-1, MCP-1, phosphorylated MAPK and NF-κB were detected using western blotting.

RESULTS

Amitriptyline increased the phosphorylation of nitric oxide synthase (eNOS) and the release of NO. Amitriptyline significantly inhibited TNF-α-induced increases in ASMase activity and the release of ceramide and downregulated TNF-α-induced expression of proinflammatory proteins, including ICAM-1, VCAM-1, and MCP-1 in ECs, as well as the secretion of sICAM-1 and sVCAM-1. TNF-α treatment obviously increased monocyte adhesion and ROS production and impaired HUVEC proliferation, migration and tube formation, while amitriptyline rescued proliferation, migration, and tube formation and decreased monocyte adhesion and ROS production. Additionally, we demonstrated that amitriptyline suppressed TNF-α-induced MAPK phosphorylation as well as the activity of NF-κB in HUVECs. The results showed that the relaxation response of aortic rings to acetylcholine in the WT-TNF-α group was much lower than that in the WT group, and the sensitivity of aortic rings to acetylcholine in the WT-TNF-α group and WT-AMI-TNF-α group was significantly higher than that in the WT-TNF-α group.

CONCLUSION

These results suggest that amitriptyline reduces endothelial inflammation, consequently improving vascular endothelial function. Thus, the identification of amitriptyline as a potential strategy to improve endothelial function is important for preventing vascular diseases.

Exploring the Multifaceted Potential of Sildenafil in Medicine

Phosphodiesterase type 5 (PDE5) is pivotal in cellular signalling, regulating cyclic guanosine monophosphate (cGMP) levels crucial for smooth muscle relaxation and vasodilation. By targeting cGMP for degradation, PDE5 inhibits sustained vasodilation. PDE5 operates in diverse anatomical regions, with its upregulation linked to various pathologies, including cancer and neurodegenerative diseases. Sildenafil, a selective PDE5 inhibitor, is prescribed for erectile dysfunction and pulmonary arterial hypertension. However, considering the extensive roles of PDE5, sildenafil might be useful in other pathologies. This review aims to comprehensively explore sildenafil's therapeutic potential across medicine, addressing a gap in the current literature. Recognising sildenafil's broader potential may unveil new treatment avenues, optimising existing approaches and broadening its clinical application.

Safety profile and signal detection of phosphodiesterase type 5 inhibitors for erectile dysfunction: a Food and Drug Administration Adverse Event Reporting System analysis

Background

Phosphodiesterase type 5 inhibitors (PDE5Is) are generally well tolerated but have been associated with uncommon and significant adverse events (AEs).

Aim

This study aims to investigate and compare the characteristics of AEs associated with PDE5Is used for erectile dysfunction and identify any safety signals in a postmarketing surveillance database between 2010 and 2021.

Methods

A descriptive analysis was conducted for all AEs reported to the Food and Drug Administration Adverse Event Reporting System for 4 PDE5Is-avanafil, sildenafil, tadalafil, and vardenafil-indicated for erectile dysfunction between January 2010 and December 2021. The frequency of the most reported AEs and outcomes were identified. A disproportionality analysis based on proportional reporting ratio (PRR) and reporting odds ratio (ROR) was conducted for the most common and clinically important AEs to identify signals to gain insights into potential differences in safety profiles.

Outcomes

The outcome measures of the study are frequency of reported AEs and outcomes following AE.

Results

A total of 29 236 AEs were reported for PDE5Is during the study period. The most reported AE was "drug ineffective" with 7115 reports (24.3%). Eight safety signals were detected across the 4 drugs. Key signals were sexual disorders (PRR, 3.13 [95% CI, 2.69-3.65]; ROR, 3.24 [95% CI, 2.77-3.79]) and death (PRR, 3.17 [2.5-4.01]; ROR, 3.211 [2.52-4.06]) for sildenafil, priapism (PRR, 3.63 [2.11-6.24]; ROR, 3.64 [2.12-6.26]) for tadalafil, and drug administration error (PRR, 2.54 [1.84-3.52]; ROR, 2.6 [1.86-3.63]) for vardenafil. The most reported outcomes were other serious events with 6685 events (67.2%) and hospitalization with 1939 events (19.5%).

Clinical Implications

The commonly reported AEs and detected signals may guide clinicians in treatment decision making for men with erectile dysfunction.

Strengths and Limitations

This is the first comprehensive report and disproportionality analysis on all types of AEs associated with PDE5Is used for erectile dysfunction in the United States. The findings should be interpreted cautiously due to limitations in the Adverse Event Reporting System, which includes self-reports, duplicate and incomplete reports, and biases in reporting and selection. Therefore, establishing a causal relationship between the reported AEs and the use of PDE5Is is uncertain, and the data may be confounded by other medications and indications.

Conclusion

PDE5Is demonstrate significantly increased risks of reporting certain clinically important AEs. While these events are not common, it is imperative to continually monitor PDE5I use at the levels of primary care to national surveillance to ensure safe utilization.

Advancements in Phosphodiesterase 5 Inhibitors: Unveiling Present and Future Perspectives

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

Erectile dysfunction, phosphodiesterase-5 inhibitor use and risk of cardiovascular disease and mortality in people with diabetes: A systematic review and meta-analysis

BACKGROUND

Phosphodiesterase-5 inhibitors (PDE5-Is), used in the management of erectile dysfunction (ED), have potential cardioprotective benefits. The impact of PDE5-Is on reducing adverse cardiovascular outcomes in patients with diabetes mellitus (DM) and ED is uncertain. Using a systematic review and meta-analysis of observational cohort studies and randomised controlled trials (RCTs), we evaluated if (i) the association of PDE5-Is in people with ED and DM and their risk of cardiovascular disease (CVD) and mortality and (ii) ED confers an excess risk of CVD and mortality in patients with DM compared with no DM.

METHODS

Studies were identified from MEDLINE, Embase, the Cochrane Library, Web of Science citation search and search of bibliographies to April 2022. Study-specific risk ratios (RRs) with 95% confidence intervals (CIs) were pooled.

RESULTS

Eighteen unique studies reported on the cardiovascular impact of ED in patients with and without DM. In the general population, the RRs (95% CIs) of ED for composite CVD/MACE, all-cause mortality, CHD and stroke were 1.43 (1.31-1.55), 1.47 (1.31-1.65), 1.59 (1.39-1.82), and 1.34 (1.15-1.56), respectively. The respective estimates were 1.68 (1.15-2.45), 1.40 (0.90-2.18), 1.41 (1.24-1.61) and 1.32 (1.09-1.60) in the diabetes population. Interaction analyses suggested similar risk in both populations. Six studies reported the cardiovascular effects of PDE5-Is in people with ED and DM. Limited RCT data showed no significant differences in the risk of major adverse cardiac event (MACE), coronary heart disease (CHD) and all-cause mortality comparing PDE5-I use with non-use: RRs (95% CIs) of 3.47 (0.17-69.19), 1.31 (0.10-16.54) and 0.35 (0.12-1.05), respectively.

CONCLUSIONS

ED confers no excess risk of CVD and mortality in patients with DM compared with no DM. Limited and inadequately powered data shows no significant differences in the risk of adverse cardiovascular outcomes comparing use of PDE5-Is with non-use in patients with ED and DM. PROSPERO Registration: CRD42022324537.

Potential diabetic cardiomyopathy therapies targeting pyroptosis: A mini review

Pyroptosis is primarily considered a pro-inflammatory class of caspase-1- and gasdermin D (GSDMD)-dependent programmed cell death. Inflammasome activation promotes the maturation and release of interleukin (IL)-1β and IL-18, cleavage of GSDMD, and development of pyroptosis. Recent studies have reported that NLRP3 inflammasome activation-mediated pyroptosis aggravates the formation and development of diabetes cardiomyopathy (DCM). These studies provide theoretical mechanisms for exploring a novel approach to treat DCM-associated cardiac dysfunction. Accordingly, this review aims to summarize studies that investigated possible DCM therapies targeting pyroptosis and elucidate the molecular mechanisms underlying NLRP3 inflammasome-mediated pyroptosis, and its potential association with the pathogenesis of DCM. This review may serve as a basis for the development of potential pharmacological agents as novel and effective treatments for managing and treating DCM.

Pharmacological developments in antihypertensive treatment through nitric oxide-cGMP modulation

Treatment of hypertension until now has been directed at inhibition of vasoconstriction, of cardiac contractility and of blood volume regulation. Despite the arsenal of drugs available for this purpose, the control of target blood pressure is still a difficult goal to reach in outpatients. The nitric oxide-cyclic guanosine monophosphate signaling is one of the most important mediators of vasodilation. It might therefore be a potential and most welcome drug target for optimization of the treatment of hypertension. In this chapter we review the problems that can occur in this signaling system, the attempts that have been made to correct these problems, and those that are still under investigation. Recently developed, clinically safe medicines that are currently approved for other applications, such as myocardial infarction, await to be tested for essential systemic hypertension. We conclude that despite many years of research without translation, stimulation of nitric oxide-cyclic guanosine monophosphate is still a viable strategy in the prevention of the health risk posed by chronic hypertension.

Deep Learning-Based Electrocardiograph in Evaluating Radiofrequency Ablation for Rapid Arrhythmia

This study is aimed at analyzing the important role of deep learning-based electrocardiograph (ECG) in the efficacy evaluation of radiofrequency ablation in the treatment of tachyarrhythmia. In this study, 158 patients with rapid arrhythmia treated by radiofrequency ablation were divided into effective treatment group (142 cases) and ineffective treatment group (16 cases). ECG examination was performed on all patients, and the indicators of ECG examination were quantified by the deep learning-based convolutional neural network model. The indicators of ECG examination of the effective treatment group and the ineffective treatment group were compared. The results showed that compared with the ineffective treatment group, the end-systolic volume (ESV), end-diastolic volume (EDV), end-systolic volume index (ESVI), and end-diastolic volume index (EDVI) of the effective treatment group were significantly decreased, and the left ventricular ejection fraction (LVEF) was significantly increased (P < 0.05). After radiofrequency ablation, the ventricular rate of patients in the effective treatment group was significantly lower than that of the ineffective treatment group at 12 h and 24 h after treatment (P < 0.05). In addition, compared with patients in the ineffective treatment group, the QT dispersion of the ECG in the effective treatment group was significantly higher (P < 0.05). The accuracy, specificity, and sensitivity of ECG in evaluating the therapeutic effect of patients with tachyarrhythmia were 86.81%, 84.29%, and 77.27%, respectively. The area under the curve was determined as 0.798 according to the receiver operating characteristic (ROC) curve of the subjects. In summary, indicators of ECG examination based on deep learning can provide auxiliary reference information for the efficacy evaluation of radiofrequency ablation in the treatment of tachyarrhythmia.