Side effects of using nitrates to treat heart failure and the acute coronary syndromes, unstable angina and acute myocardial infarction

Application of nitrates and NO-donors as a transdermal therapy for erectile dysfunction: a comprehensive review

INTRODUCTION

Erectile dysfunction (ED) is among the most prevalent urologic issues affecting men globally, with a notably high incidence rate. It significantly impacts the quality of life of patients and their sexual partners.

OBJECTIVES

Given the increasing prevalence of ED among men in recent years, numerous pharmacotherapies have been developed to address these conditions. However, systemic drug therapies for ED are often associated with significant challenges, including drug interactions and contraindications across a wide range of medical conditions. This has prompted researchers to focus on designing drugs and dosage forms that maintain efficacy while reducing side effects, interactions, and contraindications.

METHODS

Building on previous studies, this article investigates nitrates and NO-donors with a focus on their transdermal impact, strategies for enhancing therapeutic efficiency, potential local side effects, and the evaluation of various formulations.

RESULTS

In this regard, organic nitrates such as nitroglycerin and isosorbide dinitrate and NO donors comprising volatile alkyl nitrites, linsidomine, sodium nitroprusside, and L-arginine are among good candidates for transdermal formulations of ED treatment. In the current article, the topical effects of these compounds, both alone and in combination with other drugs, have been thoroughly examined, including aspects such as their mechanism of action, effectiveness, side effects, and contraindications.

CONCLUSION

Based on these findings, it appears that novel formulations with enhanced absorption of these compounds could play a significant role in the treatment of ED, either as a standalone therapy or as an adjunctive treatment. Currently, most of the data are from preclinical studies and future clinical research can reveal the precise efficacy of such transdermal formulations.

Revisiting nitrates use in pre-shock state of contemporary cardiogenic shock classification

Patients at each shock stage may behave and present differently with a spectrum of shock severity and adverse outcomes. Shock severity, shock aetiology, and several factors should be integrated in management decision-making. Although the contemporary shock stages classification provided a standardized shock severity assessment, individual agents or management strategy has not yet been studied in the context of each shock stage. The pre-shock state may comprise a wide range of presentations. Nitrate therapy has potential benefit in myocardial infarction and acute heart failure. Herein, this review aims to discuss the potential use of nitrate therapy in the context of the pre-shock state or stage B of the contemporary shock classification given its various presentations.

Nitric oxide — soluble guanylate cyclase — cyclic guanosine monophosphate signaling pathway in the pathogenesis of heart failure and search for novel therapeutic targets

Heart failure is a severe disease with an unfavorable prognosis, which requires intensification of therapy and the search for novel approaches to treatment. In this review, the physiological significance of soluble guanylate cyclase-related signaling pathway, reasons for decrease in its activity in heart failure and possible consequences are discussed. Pharmacological methods of stimulating the production of cyclic guanosine monophosphate using drugs with different mechanisms of action are considered. Data from clinical studies regarding their effectiveness and safety are presented. A promising approach is stimulation of soluble guanylate cyclase, which showed beneficial effects in preclinical studies, as well as in the recently completed phase III VICTORIA study.

Biodata Mining of Differentially Expressed Genes between Acute Myocardial Infarction and Unstable Angina Based on Integrated Bioinformatics

Acute coronary syndrome (ACS) is a complex syndrome of clinical symptoms. In order to accurately diagnose the type of disease in ACS patients, this study is aimed at exploring the differentially expressed genes (DEGs) and biological pathways between acute myocardial infarction (AMI) and unstable angina (UA). The GSE29111 and GSE60993 datasets containing microarray data from AMI and UA patients were downloaded from the Gene Expression Omnibus (GEO) database. DEG analysis of these 2 datasets is performed using the “limma” package in R software. DEGs were also analyzed using protein-protein interaction (PPI), Molecular Complex Detection (MCODE) algorithm, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Correlation analysis and “cytoHubba” were used to analyze the hub genes. A total of 286 DEGs were obtained from GSE29111 and GSE60993, including 132 upregulated genes and 154 downregulated genes. Subsequent comprehensive analysis identified 20 key genes that may be related to the occurrence and development of AMI and UA and were involved in the inflammatory response, interaction of neuroactive ligand-receptor, calcium signaling pathway, inflammatory mediator regulation of TRP channels, viral protein interaction with cytokine and cytokine receptor, human cytomegalovirus infection, and cytokine-cytokine receptor interaction pathway. The integrated bioinformatical analysis could improve our understanding of DEGs between AMI and UA. The results of this study might provide a new perspective and reference for the early diagnosis and treatment of ACS.

Therapeutic Efficacy and Safety of Safflower Injection in the Treatment of Acute Coronary Syndrome

Background

Safflower injection (SFI), a popular Chinese patent drug, is commonly used to treat acute coronary syndromes (ACSs) in China. The research seeks to scientifically estimate the clinical efficacy of SFI for ACS patients.

Methods

Eight electronic databases were retrieved for eligible research from the founding date to September 8, 2020. Odds ratio (OR) was adopted to assess the total effective rate, ECG improvement, and adverse reaction, and mean difference (MD) was used for assessing the hemorheology indexes as well as the LVEF.

Results

Sixteen randomized controlled trials involving 1620 sufferers with ACS were incorporated. The outcomes showed that, in comparison to conventional medication alone, SFI combined with conventional treatment remarkably enhanced the total effective rate (OR = 3.66, 95% CI [2.73, 4.90], P < 0.00001), ECG improvement (OR = 2.85, 95% CI [2.04, 3.99], P < 0.00001), and LVEF (MD = 5.13, 95% CI [3.73, 6.53], P < 0.00001). Moreover, SFI combined with conventional treatment significantly decreased hemorheology indexes including BV (MD = −0.95, 95% CI [−1.76, −0.13], P=0.02), HCT (MD = −2.37, 95% CI [−3.25, −1.50], P < 0.00001), FIB (MD = −0.44, 95% CI [−0.60, −0.29], P < 0.00001), and PAR (OR = −7.65, 95% CI [−10.16, −5.14], P < 0.00001). However, no notable contrast was observed to link the experimental and the control team for PV (MD = −0.42, 95% CI [−0.83, 0.00], P=0.05) and adverse reactions (OR = 0.59, 95% CI [0.13, 2.74], P=0.50).

Conclusion

Despite the limitations that existed in this meta-analysis, the outcomes demonstrated that SFI and conventional combined medication is an effective and relatively safe therapy for ACS sufferers.

Multimorbidity in Older Adults with Heart Failure

Multimorbidity is common among older adults with heart failure and creates diagnostic and management challenges. Diagnosis of heart failure may be difficult, as many conditions commonly found in older persons produce dyspnea, exercise intolerance, fatigue, and weakness; no singular pathognomonic finding or diagnostic test differentiates them from one another. Treatment may also be complicated, as multimorbidity creates high potential for drug-disease and drug-drug interactions in settings of polypharmacy. The authors suggest that management of multimorbid older persons with heart failure be patient, rather than disease-focused, to best meet patients' unique health goals and minimize risk from excessive or poorly-coordinated treatments.

Challenges with nitrate therapy and nitrate tolerance: prevalence, prevention, and clinical relevance

Nitrate therapy has been an effective treatment for ischemic heart disease for over 100 years. The anti-ischemic and exercise-promoting benefits of sublingually administered nitrates are well established. Nitroglycerin is indicated for the relief of an established attack of angina and for prophylactic use, but its effects are short lived. In an effort to increase the duration of beneficial effects, long-acting orally administered and topical applications of nitrates have been developed; however, following their continued or frequent daily use, patients soon develop tolerance to these long-acting nitrate preparations. Once tolerance develops, patients begin losing the protective effects of the long-acting nitrate therapy. By providing a nitrate-free interval, or declining nitrate levels at night, one can overcome or reduce the development of tolerance, but cannot provide 24-h anti-anginal and anti-ischemic protection. In addition, patients may be vulnerable to occurrence of rebound angina and myocardial ischemia during periods of absent nitrate levels at night and early hours of the morning, and worsening of exercise capacity prior to the morning dose of the medication. This has been a concern with nitroglycerin patches but not with oral formulations of isosorbide-5 mononitrates, and has not been adequately studied with isosorbide dinitrate. This paper describes problems associated with nitrate tolerance, reviews mechanisms by which nitrate tolerance and loss of efficacy develop, and presents strategies to avoid nitrate tolerance and maintain efficacy when using long-acting nitrate formulations.

Evaluating symptoms to improve quality of life in patients with chronic stable angina

Chronic stable angina (CSA) is a significant problem in the United States that can negatively impact patient quality of life (QoL). An accurate assessment of the severity of a patient's angina, the impact on their functional status, and their risk of cardiovascular complications is key to successful treatment of CSA. Active communication between the patient and their healthcare provider is necessary to ensure that patients receive optimal therapy. Healthcare providers should be aware of atypical symptoms of CSA in their patients, as patients may continue to suffer from angina despite the availability of multiple therapies. Patient questionnaires and symptom checklists can help patients communicate proactively with their healthcare providers. This paper discusses the prevalence of CSA, its impact on QoL, and the tools that healthcare providers can use to assess the severity of their patients' angina and the impact on QoL.

Caveolin as a potential drug target for cardiovascular protection

Caveolae and caveolin are key players in a number of disease processes. Current research indicates that caveolins play a significant role in cardiovascular disease and dysfunction. The far-reaching roles of caveolins in disease and dysfunction make them particularly notable therapeutic targets. In particular, caveolin-1 (Cav-1) and caveolin-3 (Cav-3) have been identified as potential regulators of vascular dysfunction and heart disease and might even confer cardiac protection in certain settings. Such a central role in vascular health therefore makes manipulation of Cav-1/3 function or expression levels clear therapeutic targets in a variety of cardiovascular related disease states. Here, we highlight the role of Cav-1 and Cav-3 in cardiovascular health and explore the potential of Cav-1 and Cav-3 derived experimental therapeutics.

Headache-type adverse effects of NO donors: vasodilation and beyond

Although nitrate therapy, used in the treatment of cardiovascular disorders, is frequently associated with side-effects, mainly headaches, the summaries of product characteristics of nitrate-containing medicines do not report detailed description of headaches and even do not highlight the possibility of nitrate-induced migraine. Two different types of nitrate-induced headaches have been described: (i) immediate headaches that develop within the first hour of the application, are mild or medium severity without characteristic symptoms for migraine, and ease spontaneously; and (ii) delayed, moderate or severe migraine-type headaches (occurring mainly in subjects with personal or family history of migraine), that develop 3-6 h after the intake of nitrates, with debilitating, long-lasting symptoms including nausea, vomiting, photo- and/or phono-phobia. These two types of headaches are remarkably different, not only in their timing and symptoms, but also in the persons who are at risk. Recent studies provide evidence that the two headache types are caused by different mechanisms: immediate headaches are connected to vasodilation caused by nitric oxide (NO) release, while migraines are triggered by other actions such as the release of calcitonin gene-related peptide or glutamate, or changes in ion channel function mediated by cyclic guanosine monophosphate or S-nitrosylation. Migraines usually need anti-attack medication, such as triptans, but these drugs are contraindicated in most medical conditions that are treated using nitrates. In conclusion, these data recommend the correction of summaries of nitrate product characteristics, and also suggest a need to develop new types of anti-migraine drugs, effective in migraine attacks, that could be used in patients with risk for angina pectoris.

An Implanted Closed-loop Chip System for Heart Rate Control: System Design and Effects in Conscious Rats

Objective

To evaluate the efficiency of an implanted chip system for the control of heart rate (HR).

Methods

The HR was recorded in six conscious Sprague-Dawley (SD) rats. An implanted chip system was designed to regulate the HR by stimulating the right cervical vagus nerve according to the feedback of real time HR. Each rat was subjected to 30-min regulation and 30-min recovery. The change of HR during the regulation period was compared with the control. The ECG was recorded during the experiment for 24 h.

Results

The ECG signals were successfully recorded during the experiment. The HR was significantly decreased during the period of regulation compared with control (-79.3 ±34.5, P < 0.01, n = 6) and then recovered to normal after regulation.

Conclusion

The described implanted chip system can regulate the HR to a designated set point.

The effects of nitroxyl (HNO) on soluble guanylate cyclase activity: interactions at ferrous heme and cysteine thiols

It has been previously proposed that nitric oxide (NO) is the only biologically relevant nitrogen oxide capable of activating the enzyme soluble guanylate cyclase (sGC). However, recent reports implicate HNO as another possible activator of sGC. Herein, we examine the affect of HNO donors on the activity of purified bovine lung sGC and find that, indeed, HNO is capable of activating this enzyme. Like NO, HNO activation appears to occur via interaction with the regulatory ferrous heme on sGC. Somewhat unexpectedly, HNO does not activate the ferric form of the enzyme. Finally, HNO-mediated cysteine thiol modification appears to also affect enzyme activity leading to inhibition. Thus, sGC activity can be regulated by HNO via interactions at both the regulatory heme and cysteine thiols.

NO-independent, haem-dependent soluble guanylate cyclase stimulators

The nitric oxide (NO) signalling pathway is altered in cardiovascular diseases, including systemic and pulmonary hypertension, stroke, and atherosclerosis. The vasodilatory properties of NO have been exploited for over a century in cardiovascular disease, but NO donor drugs and inhaled NO are associated with significant shortcomings, including resistance to NO in some disease states, the development of tolerance during long-term treatment, and non-specific effects such as post-translational modification of proteins. The development of pharmacological agents capable of directly stimulating the NO receptor, soluble guanylate cyclase (sGC), is therefore highly desirable. The benzylindazole compound YC-1 was the first sGC stimulator to be identified; this compound formed a lead structure for the development of optimized sGC stimulators with improved potency and specificity for sGC, including CFM-1571, BAY 41-2272, BAY 41-8543, and BAY 63-2521. In contrast to the NO- and haem-independent sGC activators such as BAY 58-2667, these compounds stimulate sGC activity independent of NO and also act in synergy with NO to produce anti-aggregatory, anti-proliferative, and vasodilatory effects. Recently, aryl-acrylamide compounds were identified independent of YC-1 as sGC stimulators; although structurally dissimilar to YC-1, they have a similar mode of action and promote smooth muscle relaxation. Pharmacological stimulators of sGC may be beneficial in the treatment of a range of diseases, including systemic and pulmonary hypertension, heart failure, atherosclerosis, erectile dysfunction, and renal fibrosis. An sGC stimulator, BAY 63-2521, is currently in clinical development as an oral therapy for patients with pulmonary hypertension. It has demonstrated efficacy in a proof-of-concept study, reducing pulmonary vascular resistance and increasing cardiac output from baseline. A full, phase 2 trial of BAY 63-2521 in pulmonary hypertension is underway.

The prince and the pauper. A tale of anticancer targeted agents

Cancer rates are set to increase at an alarming rate, from 10 million new cases globally in 2000 to 15 million in 2020. Regarding the pharmacological treatment of cancer, we currently are in the interphase of two treatment eras. The so-called pregenomic therapy which names the traditional cancer drugs, mainly cytotoxic drug types, and post-genomic era-type drugs referring to rationally-based designed. Although there are successful examples of this newer drug discovery approach, most target-specific agents only provide small gains in symptom control and/or survival, whereas others have consistently failed in the clinical testing. There is however, a characteristic shared by these agents: -their high cost-. This is expected as drug discovery and development is generally carried out within the commercial rather than the academic realm. Given the extraordinarily high therapeutic drug discovery-associated costs and risks, it is highly unlikely that any single public-sector research group will see a novel chemical "probe" become a "drug". An alternative drug development strategy is the exploitation of established drugs that have already been approved for treatment of non-cancerous diseases and whose cancer target has already been discovered. This strategy is also denominated drug repositioning, drug repurposing, or indication switch. Although traditionally development of these drugs was unlikely to be pursued by Big Pharma due to their limited commercial value, biopharmaceutical companies attempting to increase productivity at present are pursuing drug repositioning. More and more companies are scanning the existing pharmacopoeia for repositioning candidates, and the number of repositioning success stories is increasing. Here we provide noteworthy examples of known drugs whose potential anticancer activities have been highlighted, to encourage further research on these known drugs as a means to foster their translation into clinical trials utilizing the more limited public-sector resources. If these drug types eventually result in being effective, it follows that they could be much more affordable for patients with cancer; therefore, their contribution in terms of reducing cancer mortality at the global level would be greater.

Pharmacokinetics, pharmacodynamics, tolerability, and safety of the soluble guanylate cyclase activator cinaciguat (BAY 58-2667) in healthy male volunteers

Preclinical data indicate that the nitric oxide-independent soluble guanylate cyclase activator cinaciguat (BAY 58-2667), which is a new drug in development for patients with heart failure, induces vasodilation preferentially in diseased vessels. This study aimed to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of cinaciguat. Seventy-six healthy volunteers were included in this randomized, placebo-controlled study. Cinaciguat (50-250 microg/h) was administered intravenously for up to 4 hours in a maximum of 6 individuals per dose group. No serious adverse events were reported. Four-hour infusions (50-250 microg/h) decreased diastolic blood pressure and increased heart rate (all P values < .05) versus placebo, without significantly reducing systolic blood pressure (P between 0.07 and 0.56). At higher doses (150-250 microg/h), 4-hour infusions decreased mean arterial pressure and increased plasma cyclic guanosine monophosphate levels (all P values < .05). Pharmacokinetics showed dose-proportionality with low interindividual variability. Plasma concentrations declined below 1.0 microg/L within 30 minutes of cessation of infusion. Cinaciguat had potent cardiovascular effects reducing preload and afterload, warranting further investigation in patients with heart failure.