Phosphodiesterase type 5 inhibitors improve endothelial function and may benefit cardiovascular conditions

UPLC-MS/MS-Based Target Screening of 90 Phosphodiesterase Type 5 Inhibitors in 5 Dietary Supplements

The aim of individuals consuming health supplements is to attain a robust state through nutritional regulation. However, some unscrupulous manufacturers, motivated by profit, fraudulently incorporate drugs or unauthorized components with therapeutic effects into the product for instant product performance enhancement. The long-term use of these products may inadvertently inflict harm on human health and fail to promote nutritive healthcare. The illegal inclusion of these substances is prevalent in kidney-tonifying and sexuality-enhancing products. Developing effective analytical methods to identify these products and screen for illegal added ingredients can effectively prevent such products from reaching and remaining on the market. A target screening method for the detection and quantification of 90 phosphodiesterase type 5 inhibitors (PDE-5is) in 5 kinds of health products was developed and validated. The type of dietary supplements varied from tablets, capsules, and protein powder to wine and beverages. Sample preparation was completed with a one-step liquid phase extraction. The screening process of 90 PDE-5is was done efficiently within 25 min by ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) using the dynamic multiple reaction monitoring (dMRM) technique. The LODs of 90 PDE-5is were detected at levels ranging from 25 to 85 ng/g or ng/mL. This novel targeting methodology was effective and can be applied to routine market supervision. Among 286 batches of samples, 8 batches were found to be positive. Three kinds of PDE-5is were first detected in healthy products. The screening method demonstrated herein will be a promising and powerful tool for rapid screening of PDE-5is.

Endothelial Function in Pulmonary Arterial Hypertension: From Bench to Bedside

Pulmonary arterial hypertension is a complex pathology whose etiology is still not completely well clarified. The pathogenesis of pulmonary arterial hypertension involves different molecular mechanisms, with endothelial dysfunction playing a central role in disease progression. Both individual genetic predispositions and environmental factors seem to contribute to its onset. To further understand the complex relationship between endothelial and pulmonary hypertension and try to contribute to the development of future therapies, we report a comprehensive and updated review on endothelial function in pulmonary arterial hypertension.

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.

Effect of phosphodiesterase type 5 inhibitors on major adverse cardiovascular events and overall mortality in a large nationwide cohort of men with erectile dysfunction and cardiovascular risk factors: A retrospective, observational study based on healthcare claims and national death index data

BACKGROUND

Treatment with phosphodiesterase type 5 inhibitors (PDE-5is) is effective in treating erectile dysfunction (ED).

AIM

The objective of this study was to determine the effect of PDE-5is on the incidence of major adverse cardiovascular (CV) events (MACE; composite outcome of CV death, hospitalization for myocardial infarction, coronary revascularization, stroke, heart failure, and unstable angina pectoris) and overall mortality.

METHODS

A retrospective observational cohort study was conducted in a large US claims database in men with ≥1 diagnosis of ED without prior MACE within 1 year, from January 1, 2006, to October 31, 2020. The exposed group had ≥1 claim for PDE-5i and the unexposed group had no claims for PDE-5i, and the groups were matched up to 1:4 on baseline risk variables.

OUTCOME

The primary outcome was MACE and the secondary outcomes were overall mortality and individual components of MACE, determined by multivariable Cox proportional hazard modeling.

RESULTS

Matched plus multivariable analyses showed that MACE was lower by 13% in men exposed (n = 23 816) to PDE-5is (hazard ratio [HR] 0.87; 95% CI 0.79-0.95; P = .001) vs nonexposure (n = 48 682) over mean follow-up periods of 37 and 29 months, respectively, with lower incidence of coronary revascularization (HR 0.85; 95% CI 0.73-0.98; P = .029), heart failure (HR 0.83; 95% CI 0.72-0.97; P = .016), unstable angina (HR 0.78; 95% CI 0.64-0.96; P = .021), and CV death (HR 0.61; 95% CI 0.41-0.90; P = .014) with PDE-5i exposure. Phosphodiesterase type 5 inhibitor-exposed men had a 25% lower incidence of overall mortality (HR 0.75; 95% CI 0.65-0.87; P < .001). Men without coronary artery disease (CAD) but with CV risk factors at baseline showed a similar pattern. In the main study cohort, men in the highest quartile of PDE-5i exposure had the lowest incidence of MACE (HR 0.45; 95% CI 0.37-0.54; P < .001) and overall mortality (HR 0.51; 95% CI 0.37-0.71; P < .001) vs the lowest exposure quartile. In a subgroup with baseline type 2 diabetes (n = 6503), PDE-5i exposure was associated with a lower MACE risk (HR 0.79; 95% CI 0.64-0.97; P = .022).

CLINICAL IMPLICATIONS

PDE-5is may have cardioprotective effects.

STRENGTHS AND LIMITATIONS

Strengths are the large numbers of participants and consistency of the data; limitations include the retrospective nature of the study and unknown confounders.

CONCLUSIONS

In a large population of US men with ED, PDE-5i exposure was associated with lower incidence of MACE, CV death, and overall mortality risk compared to non-exposure. Risk reduction correlated with PDE-5i exposure level.

Tadalafil ameliorates memory deficits, oxidative stress, endothelial dysfunction and neuropathological changes in rat model of hyperhomocysteinemia induced vascular dementia

AIM

The present study investigates the potential of Tadalafil, a phosphodiesterase-5 inhibitor, in a rat model of hyperhomocysteinemia induced vascular dementia.

METHODS

Hyperhomocysteinemia induced vascular dementia in Wistar rats was produced by administering l-Methionine (1.7 g/kg/day; p.o.×8 weeks). Learning and memory was assessed by employing Morris water maze (MWM) test. Endothelial dysfunction was assessed through acetylcholine-induced endothelial-dependent vasorelaxation and serum nitrite levels. Various other biochemical and histopathological estimations were also performed.

RESULTS

l-Methionine produced significant impairment in acetylcholine-induced endothelium-dependent vasorelaxation and a decrease in serum nitrite levels indicating endothelial dysfunction. Further, these animals performed poorly on Morris water maze, depicting impairment of learning and memory. There was a significant rise in brain oxidative stress level (indicated by an increase in brain thiobarbituric acid reactive species and a decrease in reduced glutathione levels). Increase in brain acetylcholinesterase activity; brain myeloperoxidase activity and brain neutrophil infiltration (a marker of inflammation) were also observed. Tadalafil (5 and 10 mg/kg, p.o.)/Donepezil (0.5 mg/kg, i.p., serving as standard) treatment ameliorated l-Methionine induced endothelial dysfunction; memory deficits; biochemical and histopathological changes in a significant manner.

CONCLUSIONS

It may be concluded that tadalafil has shown efficacy in the rat model of l-Methionine induced vascular dementia and that phosphodiesterase-5 can be considered as an important therapeutic target for the treatment of vascular dementia.

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.

Established and emerging therapeutic uses of PDE type 5 inhibitors in cardiovascular disease

PDE type 5 inhibitors (PDE5Is), such as sildenafil, tadalafil and vardenafil, are a class of drugs used to prolong the physiological effects of NO/cGMP signalling in tissues through the inhibition of cGMP degradation. Although these agents were originally developed for the treatment of hypertension and angina, unanticipated side effects led to advances in the treatment of erectile dysfunction and, later, pulmonary arterial hypertension. In the last decade, accumulating evidence suggests that PDE5Is may confer a wider range of clinical benefits than was previously recognised. This has led to a broader interest in the cardiovascular therapeutic potential of PDE5Is, in conditions such as hypertension, myocardial infarction, stroke, peripheral arterial disease, chronic kidney disease and diabetes mellitus. Here, we review the pharmacological properties and established licensed uses of this class of drug, along with emerging therapeutic developments and possible future indications.

Ameliorative Effect of Phosphodiesterase-5 Inhibitor in Rat Model of Vascular Dementia

Introduction:

Cerebral hypoperfusion has been considered as major risk factor for Vascular Dementia (VaD). The present study shows the potential of Tadalafil, a phosphodiesterase-5 inhibitor, in bilateral common carotid artery occlusion (BCCAo) induced VaD in rats.

Materials and Methods:

BCCAo procedure was performed under anesthesia in wistar rats to induce VaD. Morris Water-Maze (MWM) parameter was employed on 7th day post-surgery to determine learning and memory. Escape latency time, time spent in target quadrant, Path length and average swim speed taken as important parameters in MWM. Endothelial dysfunction was assessed in isolated aorta by observing endothelial dependent vasorelaxations and levels of serum nitrite. Various biochemical and histopathological estimations were also performed.

Results:

BCCAo produced significant impairment in endothelium dependent vasorelaxation and a decrease in serum nitrite levels indicating endothelial dysfunction. Further poor performance on MWM represents impairment of learning and memory. There was a significant rise in brain oxidative stress level (indicated by increase in brain thiobarbituric acid reactive species and decrease in reduced glutathione levels). Increase in brain acetylcholinesterase activity; brain myloperoxidase activity and brain neutrophil infiltration (as marker of inflammation) were also observed. Treatment of Tadalafil (5 & 10 mg/kg, p. o.)/Donepezil (0. 5 mg/kg, i.p., serving as standard) ameliorated BCCAo induced endothelial dysfunction; memory deficits; biochemical and histopathological changes in a significant manner.

Conclusion:

It may be concluded that Tadalafil has shown efficacy in rat model of BCCAo induced VaD and that phosphodiesterase-5 can be considered as an important therapeutic target for the treatment of VaD.

Effect of prolonged treatment with phosphodiesterase-5-inhibitors on endothelial dysfunction in vascular diseases and vascular risk conditions: A systematic review analysis and meta-analysis of randomized double-blind placebo-controlled trials

OBJECTIVE

To challenge the argument that continuous use of phosphodiesterase-5-selective inhibitors may reduce endothelial cell dysfunction in patients with vascular diseases or vascular risk conditions.

DESIGN

This study included systematic reviews and meta-analysis of randomized double-blind placebo-controlled trials dealing with the prolonged use of phosphodiesterase-5-selective inhibitors. The risk of bias and quality of trials were assessed by the Cochrane algorithm. Fixed or random effect models, standardised mean differences and heterogeneity were estimated in the study.

DATA SOURCES

Systematic search for randomized double-blind placebo-controlled trials was done in PubMed, Scopus, CINAHL, Science direct and the Cochrane Library.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomized double-blind placebo-controlled trials reporting measures of endothelial cell dysfunction and/or endothelial cell activation were included.

RESULTS

On the whole, 469 subjects were allocated to the phosphodiesterase-5-selective inhibitor group, while 463 were assigned to the placebo group in 13 randomized double-blind placebo-controlled trials. Flow-mediated dilation of the brachial artery was found to improve after the administration of phosphodiesterase-5-selective inhibitors (P < 0.0001). The results were questioned by the elevated and uncorrectable heterogeneity (I²  = 92%) and the asymmetry of the funnel plot suggested a publication bias. Phosphodiesterase-5-selective inhibitors have no effect on endothelial cell dysfunction, as assessed in the resistance vessels by digital arterial tonometry. The blood level of endothelin-1 was observed to be decreased in phosphodiesterase-5-selective inhibitors arm (P = 0.03), although the effect disappeared once the publication bias and heterogeneity were corrected. The effect of phosphodiesterase-5-selective inhibitors on biomarkers of endothelial cell activation was found to be inconsistent.

CONCLUSIONS

The results on the benefits of a prolonged use of phosphodiesterase-5-selective inhibitors, with the objective of lowering endothelial cell dysfunction in patients with vascular diseases or vascular risk conditions are not convincing. This is because of the overall low quality of evidence, giving an unclear scientific support to this treatment. Systematic review registration: PROSPERO registration: CRD42017055399.

Sildenafil improves vascular endothelial function in patients with cystic fibrosis

Cystic fibrosis (CF), characterized by defective CFTR function, is associated with multiple systemic complications, including vascular dysfunction. Sildenafil, a phosphodiesterase type 5 inhibitor, not only enhances nitric oxide (NO) metabolism but has been shown to improve CFTR functionality as well. Thus, sildenafil has been proposed as a therapy to improve vascular health in CF; however, its potential therapeutic role has yet to be determined. We sought to investigate the effect of sildenafil on endothelial function in patients with CF. Patients with CF completed a randomized, double-blind, placebo-controlled, crossover study with an acute dose of sildenafil (50 mg) or placebo followed by a 4-wk open-label extension with sildenafil (20 mg/day). Flow-mediated dilation (FMD) was used to evaluate endothelial function before and after treatments. In addition, phosphorylated endothelial NO synthase (pNOS3) and total NOS3 protein expression was determined from endothelial cells that were exposed to plasma from the patients before and after 4 wk of sildenafil treatment. No changes ( P ≥ 0.110) in endothelial function were observed after the acute dose of sildenafil. However, FMD significantly ( P = 0.029) increased after 4 wk of treatment (∆FMD: 1.5 ± 2.2%). Moreover, pNOS3 protein expression significantly ( P = 0.013) increased after 4 wk of treatment (∆pNOS3: 0.31 ± 0.39 arbitrary units) and was associated ( r = 0.593, P = 0.033) with the change in FMD. These data suggest that 4 wk of sildenafil treatment can improve vascular endothelial function in patients with CF, likely through an increase in NOS3 phosphorylation. NEW & NOTEWORTHY Findings from the present study demonstrate, for the first time, significant improvement of endothelial function in patients with cystic fibrosis treated with sildenafil that is associated with greater phosphorylation of endothelial nitric oxide synthase. These results support the use of sildenafil as a potential novel therapy for this patient population.

Penile microvascular endothelial function in hypertensive patients: effects of acute type 5 phosphodiesterase inhibition

The primary aim of this study was to evaluate penile endothelial microvascular function in patients with primary arterial hypertension and age-matched normotensive subjects using laser speckle contrast imaging (LSCI). Additionally, we analyzed the acute penile microvascular effects induced by oral phosphodiesterase type 5 inhibitor (sildenafil; SIL) administration. Endothelium-dependent microvascular reactivity was evaluated in the penises and forearms of hypertensive patients (aged 58.8±6.6 years, n=34) and age-matched healthy volunteers (n=33) at rest and 60 min following oral SIL (100 mg) administration. LSCI was coupled with cutaneous acetylcholine (ACh) iontophoresis using increasing anodal currents. Basal penile cutaneous vascular conductance (CVC) values were not significantly different between control subjects and hypertensive individuals. Penile CVC values increased significantly after SIL administration in control (P<0.0001) and hypertensive (P<0.0001) subjects. Peak CVC values were not different between the two groups during penile ACh iontophoresis before SIL administration (P=0.2052). Peak CVC values were higher in control subjects than in hypertensive subjects after SIL administration (P=0.0427). Penile endothelium-dependent microvascular function is, to some extent, preserved in patients presenting with primary arterial hypertension under effective anti-hypertensive treatment. LSCI may be a valuable non-invasive tool for the evaluation of penile vascular responses to phosphodiesterase type 5 inhibitor.

Nucleic Acid Delivery for Endothelial Dysfunction in Cardiovascular Diseases

Endothelial dysfunction has been implicated in the pathophysiology of multiple cardiovascular diseases and involves components of both innate and acquired immune mechanisms. Identifying signature patterns and targets associated with endothelial dysfunction can help in the development of novel nanotherapeutic platforms for treatment of vascular diseases. This review discusses nucleic acid-based regulation of endothelial function and the different nucleic acid-based nanotherapeutic approaches designed to target endothelial dysfunction in cardiovascular disorders.

Therapeutic implications from the pathogenesis of Raynaud's phenomenon

INTRODUCTION

Raynaud's phenomenon (RP) can be either primary (idiopathic) or secondary to a number of different diseases/conditions, when vasopasm can be superimposed upon structural vascular abnormality or a hyperviscosity state and may then lead to severe ischaemia with tissue damage. Treatment must be tailored to the individual. Areas covered: This review discusses how increased understanding of the pathogenesis of RP has driven and is driving new approaches to therapy, and how we are now better able to predict which patients presenting with RP are likely to have an underlying disease requiring specific intervention. Medline searches (1946 to August 2016) were conducted for 'Raynaud's' in combination with relevant terms including different drugs. All papers identified were English language, with abstracts. Expert commentary: Randomised controlled trials of RP present particular challenges. The major aim must continue to be development of safe, effective treatments for patients across the spectrum of RP.

Atorvastatin and sildenafil decrease vascular TGF-β levels and MMP-2 activity and ameliorate arterial remodeling in a model of renovascular hypertension

Imbalanced matrix metalloproteinase (MMP)-2 activity and transforming growth factor expression (TGF-β) are involved in vascular remodeling of hypertension. Atorvastatin and sildenafil exert antioxidant and pleiotropic effects that may result in cardiovascular protection. We hypothesized that atorvastatin and sildenafil alone or in association exert antiproliferative effects by down-regulating MMP-2 and TGF-β, thus reducing the vascular hypertrophy induced by two kidney, one clip (2K1C) hypertension.

Sham and 2K1C rats were treated with oral atorvastatin 50 mg/kg, sildenafil 45 mg/kg, or both, daily for 8 weeks. Blood pressure was monitored weekly. Morphologic changes in the aortas were studied. TGF-β levels were determined by immunofluorescence. MMP-2 activity and expression were determined by in situ zymography, gel zymography, Western blotting, and immunofluorescence. The effects of both drugs on proliferative responses of aortic smooth muscle cells to PDGF and on on MMP-2 activity in vitro were determined. Atorvastatin, sildenafil, or both drugs exerted antiproliferative effects in vitro. All treatments attenuated 2K1C-induced hypertension and prevented the increases in the aortic cross-sectional area and media/lumen ratio in 2K1C rats. Aortas from 2K1C rats showed higher collagen deposition, TGF-β levels and MMP-2 activity and expression when compared with Sham-operated animals. Treatment with atorvastatin and/or sildenafil was associated with attenuation of 2K1C hypertension-induced increases in these pro-fibrotic factors. However, these drugs had no in vitro effects on hr-MMP-2 activity.

Atorvastatin and sildenafil was associated with decreased vascular TGF-β levels and MMP-2 activity in renovascular hypertensive rats, thus ameliorating the vascular remodeling. These novel pleiotropic effects of both drugs may translate into protective effects in patients.

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Atorvastatin and sildenafil exert antioxidant and other pleotropic effects.

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Imbalanced MMP-2 activity and TGF-β expression promote vascular remodeling in hypertension.

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Atorvastatin and sildenafil exerted antiproliferative effects in vitro.

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Both drugs prevented hypertension-induced increases pro-fibrotic factors.

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These additional pleiotropic effects may translate into protective effects in patients.

Therapy of endocrine disease. Effects of chronic use of phosphodiesterase inhibitors on endothelial markers in type 2 diabetes mellitus: a meta-analysis

OBJECTIVE

Diabetes mellitus (DM) is associated with endothelial dysfunction, reducing nitric oxide-dependent vasodilation, and increasing production of pro-inflammatory factors, leading to an increased risk of long-term cardiovascular disease. As the effects of phosphodiesterase 5 inhibitors (PDE5i) on endothelial function have not been systematically investigated, we conducted a meta-analysis of available randomized clinical trials (RCTs).

DESIGN

A thorough search of the literature was carried out. Relevant studies were considered according to RCT study design, enrollment of men with type 2 DM, chronic administration of PDE5i, and evaluation of endothelial function through both hemodynamic and endothelial inflammation-related parameters.

RESULTS

Fifteen studies fulfilled the eligibility criteria but only six RCTs met the inclusion criteria and were analyzed for 476 diabetic men, 239 randomized to Sildenafil, and 237 to placebo respectively. Four RCTs evaluated flow-mediated dilation (FMD), demonstrating a weighted mean increase of 2.19% (95% CI 0.48 to 3.90). This result showed a high heterogeneity (I(2): 98%). Thus, a further sub-group meta-analysis was performed and this analysis confirmed a significant, Sildenafil-related FMD improvement. Sildenafil improved endothelin 1 and high sensitivity C-reactive protein by ∼-0.94 pg/ml and -0.36 mg/l, respectively, not reaching statistical significance (P=0.69 and P=0.22 respectively). Finally, Sildenafil administration significantly reduced serum levels of interleukin 6 (IL6, -0.82 pg/ml; 95% CI -1.58 to -0.07).

CONCLUSION

This meta-analysis suggests a beneficial effect of chronic PDE5i administration on endothelial function. Chronic Sildenafil administration seems to improve hemodynamic (FMD) and serum pro-inflammatory makers (IL6) in diabetic men. Larger studies are needed to confirm the effects of chronic PDE5i on endothelial function.

Serum High-Sensitivity C-Reactive Protein Levels and Response to 5 mg Tadalafil Once Daily in Patients With Erectile Dysfunction and Diabetes

Purpose

We studied the relative importance of high-sensitivity C-reactive protein (hs-CRP) concentrations in patients with erectile dysfunction (ED) and diabetes and determined whether the hs-CRP level predicts the response to treatment with 5 mg tadalafil once daily.

Materials and Methods

We enrolled 102 men (aged 40-60 years) with diabetes and ED. All patients completed the International Index of Erectile Function (IIEF) questionnaire and were given 5 mg tadalafil daily. The IIEF and serum hs-CRP levels in patients and healthy controls and in patient responders and nonresponders to 5 mg tadalafil once daily were compared.

Results

Median age was 53.2 years (range, 45 to 62 years) in patients and 55.6 years (range, 47 to 64 years) in healthy controls (p=0.158). The median duration of diabetes was 54.3 months (range, 34 to 70 months). The median IIEF and hs-CRP level were 12.1 (range, 5 to 20) and 0.21 mg/dL (range, 0.05 to 0.6 mg/dL) in patients and 28.2 (range, 13 to 31) and 0.09 mg/dL (range, 0.04 to 0.2 mg/dL) in the controls, respectively (pIIEF=0.000, pCRP=0.031). After tadalafil treatment, 71 patients (69.6%) achieved an erection sufficient for sexual intercourse, whereas 31 (30.4%) did not. The median age of the tadalafil nonresponders was 56.2 years (range, 45 to 64 years) and that of the responders was 51.3 years (range, 42 to 62 years; p=0.065). Median hs-CRP levels were 0.31 mg/dL (range, 0.18 to 0.62 mg/dL) in nonresponders and 0.14 mg/dL (range, 0.09 to 0.4 mg/dL) in responders, respectively (p=0.028).

Conclusions

Serum hs-CRP was significantly higher in patients with ED and diabetes mellitus than in patients without ED. A significant correlation was observed between serum hs-CRP levels, the degree of ED, and responsiveness to tadalafil.

Antagonist molecules in the treatment of angina

INTRODUCTION

Management of chronic angina has evolved dramatically in the last few decades with several options for pharmacotherapy outlined in various evidence-based guidelines.

AREAS COVERED

There is a growing list of drugs that are currently being investigated for treatment of chronic angina. These also include several herbal medications, which are now being scientifically evaluated as potential alternative or even adjunctive therapy for angina. Gene- and cell-based therapies have opened yet another avenue for management of chronic refractory angina in 'no-option' patients who are not candidates for either percutaneous or surgical revascularization and are on optimal medical therapy. An extensive review of literature using PUBMED, Cochrane database, clinical trial databases of the USA and European Union was done and summarized in this review. This review will attempt to discuss the traditional as well as novel therapeutic agents for angina.

EXPERT OPINION

Several pharmacological and non-pharmacological therapeutic options are now available for treatment and management of chronic refractory angina. Renewed interest in traditional therapies and cell- and gene-based modalities with targeted drug delivery systems will open the doors for personalized therapy for patients with chronic refractory angina.