Comparison of effects on systolic and diastolic left ventricular function of nebivolol versus atenolol in patients with uncomplicated essential hypertension

Mechanisms regarding cardiac toxicity triggered by up-regulation of miR-144 in larval zebrafish upon exposure to triclosan

Although triclosan (TCS) is ubiquitously detected in environmental media and organisms, little information is available on its cardiotoxicity and underlying mechanisms. Herein, acute TCS exposure (0.69-1.73 μM) to zebrafish from embryos (6 hpf) to larvae (72 hpf) resulted in cardiac development defects, including increased angle between atrium and ventricle, prolonged SV-BA distance, linearized heart and pericardial cyst in 72-hpf larvae. These malformations resulted from interfered oxidative-stress pathways, reflecting in accumulated ROS and MDA and inhibited SOD and CAT activities. By RT-qPCR, the transcription levels of four cardiac development-related marker genes were significantly up-regulated except for gata4. Besides, miR-144 was identified as a regulatory molecule of TCS-induced cardiac defects by integrating analyses of artificial intervene expression and RNA-Seq data. Interestingly, the target genes of miR-144 were found and interacted with the above marker genes through constructing protein-protein interaction networks. After intervening the expression of miR-144 by microinjecting and activating Wnt pathway by an agonist BML-284, we confirmed that up-regulated miR-144 suppressed the expression of angiogenesis-related genes and negatively regulated Wnt pathway, further triggering angiogenesis disorders and cardiac phenotypic malformation. These findings unravel the underlying molecular mechanisms regarding TCS-induced cardiac development toxicity, and contribute to early warning and risk management of TCS.

Nebivolol for the Treatment of Essential Systemic Arterial Hypertension: A Systematic Review and Meta-Analysis

INTRODUCTION

Cardiovascular diseases are the main cause of mortality worldwide, and systemic arterial hypertension is associated with a large number of these cases. The objective of health professionals and health policies should be searching for the best therapeutics to control this disease. A recent consensus indicated that β-blockers have recently lost their place in initial indications for the treatment of systemic arterial hypertension and are now more indicated for the treatment of hypertension in association with other clinical situations such as angina, heart failure and arrhythmia; however, it is known that this approach was based on studies that evaluated older β-blockers such as atenolol.

OBJECTIVE

The main objective of this study was to perform a systematic review with subsequent meta-analysis on the use of nebivolol for hypertensive disease treatment, comparing it with drugs of the main antihypertensive classes.

METHODS

This systematic review was based on a search of the MEDLINE (via Pubmed), Scopus, Cochrane, International Pharmaceuticals Abstracts (IPA), and Lilacs databases for randomized and double-blind clinical trials. In addition, we also searched for gray literature studies, to 31 July 2015. Next, a cumulative meta-analysis was performed, with studies being added in a sequential manner, evaluating their impact on the combined effect. For this project, we only meta-analyzed direct comparisons of random effect.

RESULTS

Overall, 981 clinical trials were included in this systematic review. After careful analysis, 34 randomized and double-blind clinical trials were included to investigate the efficacy of nebivolol on systolic (SBP) and diastolic blood pressure (DBP) control and adverse effects. The study population comprised 12,465 patients with systemic arterial hypertension (SAH) aged between 18 and 85 years; 17% of subjects were of Black ethnicity, approximately 55% were men, and almost 10% had diabetes. In SBP management, nebivolol was superior to other β-blockers and diuretics and showed no difference in efficacy when compared with angiotensin receptor blockers or calcium channel blockers. There were insufficient studies on angiotensin-converting enzyme inhibitors for adequate comparison of both SBP and DBP control. For DBP control, nebivolol was more efficient than other β-blockers, angiotensin receptor blockers, diuretics, and calcium channel blockers.

DISCUSSION

Nebivolol is a third-generation β-blocker with additional capabilities to improve blood pressure levels in patients with arterial hypertension, because it acts by additional mechanisms such as endothelium-dependent vasodilation associated with L-arginine and oxide nitric acid, nitric oxide activity on smooth muscle cells, decreasing platelet aggregation, and leukocyte adhesion in the endothelium, decreasing oxidative stress. Although nebivolol has shown good results in controlling hypertension in this study (with few adverse events when compared with placebo treatment) and has an unquestionable benefit in individuals with heart failure (mainly with reduced ejection fraction), there is a lack of studies proving the benefit of this drug for controlling hypertension and reducing clinical outcomes such as cardiovascular (or general) mortality, acute myocardial infarction, or stroke.

CONCLUSIONS

Nebivolol demonstrated at least similar control of blood pressure levels in hypertensive individuals when compared with drugs of the most used classes. In addition, in relation to the control of arterial hypertension, studies with clinical outcomes should be performed to ensure the use of this drug in detriment to others with these well-established results.

The Effect of Nebivolol on Office Blood Pressure of Blacks Residing in Sub-Saharan Africa (A Pilot Study)

Introduction: There is substantial clinical evidence that monotherapy with beta-blockers are less effective in reducing blood pressure among hypertensive Black patients compared to Whites. The highly selective beta-1 agents like nebivolol and bisoprolol have, however, been reported to be effective in reducing blood pressure in African Americans. However, results in African Americans cannot be extrapolated to native Africans because of genetic admixture and gene-environment interaction. There is, therefore, the need for us to generate data that are applicable to Africans residing in sub-Saharan Africa. We therefore decided to evaluate the efficacy and tolerability of highly selective beta-1 agent nebivolol in hypertensive Black patients residing in sub-Saharan Africa. Materials and Methods: The nebivolol study was a multicenter, prospective, observational program among hypertensive patients with 4- and 8-week follow up which was conducted in 5 cities in Nigeria of Abuja, Calabar, Enugu, Oghara, and Port Harcourt. Dosages of nebivolol used in keeping with local prescribing information were 5 and 10 mg once daily each. The effectiveness of treatment was assessed by change from baseline in mean office systolic and diastolic blood pressures, and the proportion of patients achieving the therapeutic goal of <140/90 mmHg. Safety and tolerability of this medication were also assessed. Results: We report the results of the 140 patients studied. The mean age and body mass index were 46.9 ± 7.3 years and 22.3 ± 5.8 kg/m², respectively, and 57.1% were female. Nebivolol reduced SBP and DBP by 7.6 and 6.6 mmHg, respectively, in 4 weeks, and by 11.1 and 8.0 mm Hg, respectively, in 8 weeks. Blood pressure control was achieved in 54.8% of the patients in 4 weeks and increased to 60.4% in 8 weeks. There was no change in metabolic profile between randomization and at 8 weeks, and erectile dysfunction occurred in 1.3% of the study population. Conclusions: Nebivolol 5 and 10 mg appear efficacious in Nigerian Africans with no negative metabolic effect and minimal side effect profile. Clinical Trial Registration: www.ClinicalTrials.gov, Study Identification: NCT03598673.

Prediction of drug-disease associations based on ensemble meta paths and singular value decomposition

Background

In the field of drug repositioning, it is assumed that similar drugs may treat similar diseases, therefore many existing computational methods need to compute the similarities of drugs and diseases. However, the calculation of similarity depends on the adopted measure and the available features, which may lead that the similarity scores vary dramatically from one to another, and it will not work when facing the incomplete data. Besides, supervised learning based methods usually need both positive and negative samples to train the prediction models, whereas in drug-disease pairs data there are only some verified interactions (positive samples) and a lot of unlabeled pairs. To train the models, many methods simply treat the unlabeled samples as negative ones, which may introduce artificial noises. Herein, we propose a method to predict drug-disease associations without the need of similarity information, and select more likely negative samples.

Results

In the proposed EMP-SVD (Ensemble Meta Paths and Singular Value Decomposition), we introduce five meta paths corresponding to different kinds of interaction data, and for each meta path we generate a commuting matrix. Every matrix is factorized into two low rank matrices by SVD which are used for the latent features of drugs and diseases respectively. The features are combined to represent drug-disease pairs. We build a base classifier via Random Forest for each meta path and five base classifiers are combined as the final ensemble classifier. In order to train out a more reliable prediction model, we select more likely negative ones from unlabeled samples under the assumption that non-associated drug and disease pair have no common interacted proteins. The experiments have shown that the proposed EMP-SVD method outperforms several state-of-the-art approaches. Case studies by literature investigation have found that the proposed EMP-SVD can mine out many drug-disease associations, which implies the practicality of EMP-SVD.

Conclusions

The proposed EMP-SVD can integrate the interaction data among drugs, proteins and diseases, and predict the drug-disease associations without the need of similarity information. At the same time, the strategy of selecting more reliable negative samples will benefit the prediction.

Risk of Hospitalization for Cardiovascular Events with β-Blockers in Hypertensive Patients: A Retrospective Cohort Study

INTRODUCTION

β-Blockers are a heterogenous class of drugs that are no longer recommended for initial antihypertension monotherapy due to unfavorable long-term cardiovascular events observed with non-vasodilatory β-blockers. However, the comparative cardiovascular event risk between the vasodilatory β₁-selective antagonist/β₃ agonist nebivolol and non-vasodilatory β₁-blockers, atenolol and metoprolol, is unknown.

METHODS

Incident nebivolol, atenolol, or metoprolol monotherapy users with hypertension were identified using US claims data (2007-2014). The first β-blocker claim on/after 1/1/2008 defined the index drug/date. Hypertensive patients without pre-index cardiovascular history were followed until index drug discontinuation (> 90 day supply gap), use of other β-blockers, or end of continuous plan enrollment. Patients were pair-wise propensity score-matched using logistic regression, adjusted for baseline demographics, Charlson Comorbidity Index score, comorbid chronic pulmonary disease, rheumatic disease, renal disease, and diabetes, and use of other antihypertensive drugs during baseline. Time to first hospital claim for a cardiovascular event was assessed via Cox proportional hazards regression, adjusted for the variables above.

RESULTS

Inclusion criteria were met by 81,402 patients (n = 27,134 in each matched treatment cohort), with no between-cohort differences in baseline characteristics, comorbid conditions, or average follow-up duration. Atenolol and metoprolol cohorts had greater risk of hospitalization for a composite event (myocardial infarction, angina, congestive heart failure, stroke) than nebivolol users (adjusted hazard ratios [95% confidence interval] atenolol: 1.68 [1.29, 2.17]; metoprolol: 2.05 [1.59, 2.63]; P < 0.001, both). Risks of most individual cardiovascular events were also lower with nebivolol, including myocardial infarction and angina versus atenolol, and myocardial infarction, congestive heart failure, and angina versus metoprolol (P < 0.05, all).

CONCLUSIONS

Nebivolol was associated with significantly lower risk of hospitalization due to composite cardiovascular events than atenolol or metoprolol in this large retrospective cohort study of monotherapy with three different β₁-selective blockers in hypertensive patients.

FUNDING

Allergan plc, Madison, NJ, USA.

A retrospective study evaluating the tolerability and effectiveness of adjunctive antihypertensive drugs in patients with inadequate response to initial treatment

Real‐world tolerability and effectiveness of nebivolol as first add‐on therapy were compared with hydrochlorothiazide, metoprolol, and amlodipine. Medical records of hypertensive adults initiating nebivolol, hydrochlorothiazide, metoprolol, or amlodipine as first add‐on therapy between December 16, 2010 and July 21, 2011 were retrospectively abstracted (N = 1600; 400/treatment). Outcomes included medication‐related side‐effect rates and blood pressure (BP) reduction and control. Compared with nebivolol, metoprolol and amlodipine had significantly higher side‐effect rates (incidence rate ratio [95% CI]: 1.82 [1.14‐2.92] and 2.67 [1.69‐4.21]), respectively); the hydrochlorothiazide‐nebivolol rate ratio was not significant (1.61 [0.95‐2.71]). All treatments reduced BP at 2 months. Metoprolol, amlodipine, and hydrochlorothiazide were associated with significantly lower odds of achieving 2‐month BP control than nebivolol (odds ratios [95% CI]: 0.34 [0.23‐0.51], 0.51 [0.35‐0.75] and 0.66 [0.44‐0.99], respectively). In a real‐world setting, nebivolol as first add‐on therapy was associated with fewer side effects than metoprolol or amlodipine and with a higher BP control rate than hydrochlorothiazide, metoprolol, or amlodipine.

Novel bio analytical method development, validation and application for simultaneous determination of nebivolol and S-amlodipine in human plasma using ultra performance liquid chromatography-tandem mass spectrometry

A sensitive and specific ultra-performance liquid chromatography tandem mass spectrometric (UPLC-MS/MS) method has been developed, validated and applied for the assay of Nebivolol and S-amlodipine in human plasma. Sample extraction was carried out through hybrid extraction method from 250 μL of human plasma sample. Linearity of the method was (r ≥ 0.9996) was found to be dynamic for both the analytes over concentration range of 25.0-4000 pg/mL. Chromatographic separation was achieved on UPLC column {Waters Acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 micrometer)} with the mobile phase composition of 0.1% (v/v) formic acid in 5 mM Ammonium formate in water-acetonitrile (20:80, %v/v). Analytes Stability was assured under different requisite conditions in human plasma, reconstitution solution and diluents. Inter and intra-day assay precision and relative error (accuracy) were within ±5% for both analytes. The method was applied and reproduced to support a pharmacokinetic study of 5 mg Nebivolol (NEB) and 2.5 mg S-amlodipine (LAM) tablet on 9 healthy subjects.

Differential Metabolic Effects of Beta-Blockers: an Updated Systematic Review of Nebivolol

Blood pressure management in hypertensive patients with metabolic abnormalities is challenging, since many of the antihypertensive drugs adversely affect metabolism. Besides effective control of blood pressure in patients with hypertension, third-generation beta-blockers such as nebivolol offer additional benefits for central hemodynamics and neutral or beneficial effects on metabolism. Emerging clinical data suggest that nebivolol also has similar effects on metabolism in obese hypertensive and hypertensive diabetic patients. The present article will provide a systematic analysis of the pathophysiological links among hypertension, insulin resistance, and metabolic syndrome. We will also summarize the available clinical evidence regarding the metabolic effects of beta-blockers in hypertensive patients, with an emphasis on nebivolol. Nebivolol exerts neutral or beneficial effects on insulin sensitivity and lipid metabolism in hypertensive patients, owing to its nitric oxide-mediated vasodilatory and antioxidative properties. Thus, nebivolol could be a favorable therapeutic option for the treatment of hypertension in patients with impaired glucose and lipid metabolism.

Protective effects of nebivolol from oxidative stress to prevent hypertension-related target organ damage

Hypertension is one of the leading risk factors for morbidity and mortality in patients with cardiovascular and cerebrovascular diseases and renal impairment. It also leads to target organ damage (TOD), which worsens organ function and the patient's clinical status. Reactive oxygen species (ROS)-mediated oxidative stress may contribute significantly to TOD in patients with hypertension. NO (nitric oxide) is a paracrine factor derived from endothelial cells that has been shown to alleviate ROS-mediated oxidative damage. Nebivolol is a third-generation β-blocker with vasodilator activity, both actions contributing to decreased blood pressure in hypertensive patients. Its vasodilatory function is mediated by the endothelial l-arginine NO pathway. Nebivolol increases the bioavailability of NO in the vasculature. Its efficacy and safety profile is comparable to other commonly used antihypertensive agents. In this article, we review the current literature to understand TOD secondary to oxidative stress in patients with hypertension and the role of nebivolol in its prevention. A better understanding of the underlying mechanisms by which nebivolol reduces ROS-mediated TOD will not only help in the development of targeted therapies but may also improve health outcomes in hypertensive patients.

Hypertension treatment in the Asia-Pacific: the role of and treatment strategies with nebivolol

Hypertension is a common disease, and hypertensive patients are at increased risk of cardiovascular events. The prevalence and socioeconomic burden of hypertension in the Asia-Pacific region are predicted to increase in the coming decades. Effective blood pressure lowering reduces overall cardiovascular morbidity and mortality in patients, yet doubt has been raised regarding the use of (mainly older generation) β-blockers as initial therapy in hypertension. Consequently, several international treatment guidelines do not recommend β-blockers for the treatment of hypertension. However, in contrast to first-generation and second-generation β-blockers, the third-generation, vasodilating β-blocker nebivolol has a considerably better metabolic, haemodynamic and side effect profile. In addition to providing effective blood pressure control similar to other β-blockers and drugs from other antihypertensive classes, nebivolol exerts a dual mechanism for increasing the bioavailability of the naturally occurring vasodilator nitric oxide. The clinical benefits and significance of enhancing nitric oxide levels in hypertensive patients have been shown in direct comparisons of nebivolol with other β-blockers. While β-blockers generally provide comparable blood pressure reductions, only nebivolol demonstrated enhanced vasodilation and blood flow by increasing the expression of endothelial nitric oxide synthase and therefore increasing nitric oxide release from the endothelium. In contrast to other β-blockers, therefore, it has been suggested that nebivolol has beneficial effects in several hypertensive subgroups due to its vasodilating properties. Considering the existing data, it may be timely for treatment guidelines to recommend third-generation vasodilating β-blockers as a first-line option for the pharmacotherapy of hypertension.

Development, evaluation, and influence of formulation and process variables on in vitro performance of oral elementary osmotic device of atenolol

Purpose:

Osmotic devices are the most promising strategy-based systems for controlled drug delivery. By optimizing formulation and processing parameters, possible to develop osmotic systems to deliver drugs at predetermined rate with high in vitro-in vivo correlation. The aim of the present investigation was to develop an oral elementary osmotic pump (EOP) of atenolol with zero-order or near zero-order drug release profile.

Materials and Methods:

Differential scanning calorimetry and Fourier transform-infrared spectroscopy studies did not show any evidence of interaction between the drug and excipients. Formulations were prepared by wet granulation method and coated with cellulose acetate (CA)/ethyl cellulose containing varying amounts of dibutyl phthalate (DBP)/poly (ethylene glycol)-400 as a plasticizer. The effect of different formulation variables on drug release: type and concentration of osmogen and plasticizer, size of the delivery orifice, nature of the rate controlling membrane, and membrane weight gain were studied. The release studies also compared with marketed immediate release formulation.

Results:

Formulations containing NaCl, mannitol, and combination of both as osmogens in the drug:osmogen ratio of 1:3 and 1:4 showed zero-order drug release. Marketed tablet releases more than 95% drug in different media in 90 min. The 4% CA in acetone with DBP as a plasticizer (at a concentration of 15% w/w of polymer), with orifice diameter 565 μm, and 8.05% increase in weight on coating were found to control the drug release independent of pH and agitational intensity. The formulations were stable for 3 months as per the International Council for Harmonisation guidelines.

Conclusion:

Atenolol containing EOPs and process parameters on release studies were studied and confirmed based on osmotic technology.

A Review of Nebivolol Pharmacology and Clinical Evidence

Nebivolol is a highly selective β1-adrenergic receptor antagonist with a pharmacologic profile that differs from those of other drugs in its class. In addition to cardioselectivity mediated via β1 receptor blockade, nebivolol induces nitric oxide-mediated vasodilation by stimulating endothelial nitric oxide synthase via β3 agonism. This vasodilatory mechanism is distinct from those of other vasodilatory β-blockers (carvedilol, labetalol), which are mediated via α-adrenergic receptor blockade. Nebivolol is approved for the treatment of hypertension in the US, and for hypertension and heart failure in Europe. While β-blockers are not recommended within the current US guidelines as first-line therapy for treatment of essential hypertension, nebivolol has shown comparable efficacy to currently recommended therapies in lowering peripheral blood pressure in adults with hypertension with a very low rate of side effects. Nebivolol also has beneficial effects on central blood pressure compared with other β-blockers. Clinical data also suggest that nebivolol may be useful in patients who have experienced erectile dysfunction while on other β-blockers. Here we review the pharmacological profile of nebivolol, the clinical evidence supporting its use in hypertension as monotherapy, add-on, and combination therapy, and the data demonstrating its positive effects on heart failure and endothelial dysfunction.

Nebivolol and valsartan as a fixed-dose combination for the treatment of hypertension

INTRODUCTION

The fixed-dose combination of nebivolol and valsartan drug has been clinically evaluated and demonstrated to represent a unique combination of nebivolol, a selective β1-adrenoceptor antagonist and a β3-adrenoceptor agonist; β3 receptor activation increases endothelial nitric oxide and produces vasodilation. Valsartan is highly selective angiotensin AT1 receptor blocker and exerts its major pharmacological effect by decreasing angiotensin II-induced vasoconstriction and production of aldosterone. The addition of nebivolol counteracts the effects of increased angiotensin II concentrations resulting from potent AT1 blockade. This review describes a recently completed trial establishing the efficacy of the nebivolol/valsartan combination.

AREAS COVERED

This review provides a literature search of pertinent pharmacological and clinical data that describes the mechanisms of both drugs individually and the results of a clinical trial comparing fixed-dose combinations of nebivolol with valsartan as compared with each drug as monotherapy.

EXPERT OPINION

Fixed-dose combination drugs are intended to improve patient compliance and reduce drug costs, as well as to reduce long-term cardiovascular event rates and block counter-regulatory effects due to monotherapy. The vast majority of hypertensive patients will require at least two medications. We believe that the clinical evidence suggests that the combination of nebivolol with valsartan offers a definite clinical benefit, combining β1-adrenoceptor and angiotensin AT1 receptor blockade with β3 receptor activation and resultant increase in nitric oxide and vasodilation.

Cost-effectiveness analysis of nebivolol and metoprolol in essential hypertension: a pharmacoeconomic comparison of antihypertensive efficacy of beta blockers

OBJECTIVE

To estimate and compare the cost-effectiveness and safety of nebivolol with sustained-release metoprolol in reducing blood pressure by 1 mm of Hg per day in hypertensive patients.

MATERIALS AND METHODS

This was a prospective, randomized, open label, observational analysis of cost-effectiveness, in a questionnaire-based fashion to compare the cost of nebivolol (2.5 mg, 5 mg, 10 mg) and sustained released metoprolol succinate (25 mg, 50 mg, 100 mg) in hypertensive patients using either of the two drugs. A total of 60 newly detected drug naïve hypertensive patients were considered for the comparison, of which 30 patients were prescribed nebivolol and the other 30 were prescribed metoprolol succinate as per the recommended dosage. Based on the data, statistical analysis was carried out using GraphPad Prism 5 and MS Excel Spreadsheet 2007.

RESULT

The cost of reducing 1 mm of Hg blood pressure per day with nebivolol was 0.60, 0.70, and 1.06 INR, whereas that of metoprolol succinate was 0.93, 1.18, and 1.25 INR at their respective equivalent doses, hence significantly lower with the nebivolol group as compared to the metoprolol group (P < 0.05).

CONCLUSION

This pharmacoeconomic analysis shows that nebivolol is more cost-effective as compared to metoprolol when the cost per reduction in blood pressure per day is considered. This may affect the patients economically during their long-term use of these molecules for the treatment of hypertension.

[The role of β-blockers in patients with metabolic syndrome and hypertension]

The choice of treatment of patients with hypertension should not be based solely on the blood pressure value, because the risk of cardiovascular diseases are influenced by the presence and magnitude of other risk factors, too. The presence of a metabolic disease (diabetes mellitus, metabolic syndrome) itself categorizes the patient as a high risk individual. In such cases the use of combined treatment is usually considered. For example, in case of hypertension aggravated by left ventricular dysfunction, ischaemic heart disease or cardiac insufficiency, β-blocker treatment is usually included in the combination of the first setting.

Formulation and in vitro evaluation of bilayer tablets of nebivolol hydrochloride and nateglinide for the treatment of diabetes and hypertension

Diabetes mellitus (DM) and hypertension are two common diseases that often coexist. The most common cause of death in the diabetic patient is heart disease. In the present investigation we combine Nebivolol and Nateglinide for better patient compliance. IR layer was formulated using various superdisintegrants like Crospovidone, Croscarmellose sodium, and sodium starch glycolate and SR layer was formulated using polymers and gums like HPMC E₁₅, ethyl cellulose, Gaur gum, and Xanthan gum. The disintegration and dissolution study of both layers showed that inclusion of surfactant (sodium lauryl sulphate) to the tablet formulation (IR) and dissolution medium (SR) enhanced the release of drugs from both layers. Kinetic studies of optimized IR layer (NBL8) and SR layer (N9) showed good linearity with regression coefficient of 0.9714 (Higuchi model) and 0.9931 (zero order kinetics), respectively. The above results reveal that the optimized IR layer of Nebivolol (NBL8) and SR layer of Nateglinide (N9) might be suitable for the treatment of diabetes and hypertension by sequential release of the two drugs in a bilayer tablet. IR-immediate release, SR-sustain release, NBL8-Nebivolol 8, N9-Nateglinide 9.

Clinical utility of fixed-dose combinations in hypertension: evidence for the potential of nebivolol/valsartan

Despite significant advances in pharmacologic approaches to treat hypertension during the last decades, hypertension- and hypertension-related organ damage are still a high health and economic burden because a large proportion of patients with hypertension do not achieve optimal blood pressure control. There is now general agreement that combination therapy with two or more antihypertensive drugs is required for targeted blood pressure accomplishment and reduction of global cardiovascular risk. The goals of combination therapies are to reduce long-term cardiovascular events by targeting different mechanism underlying hypertension and target organ disease, to block the counterregulatory pathways activated by monotherapies, to improve tolerability and decrease the adverse effects of up-titrated single agents, and to increase persistence and adherence with antihypertensive therapy. Multiple clinical trials provide evidence that fixed-dose combinations in a single pill offer several advantages when compared with loose-dose combinations. This review discusses the advances in hypertension control and associated cardiovascular disease as they relate to the prospect of combination therapy targeting a third-generation beta (β) 1-adrenergic receptor (nebivolol) and an angiotensin II receptor blocker (valsartan) in fixed-dose single-pill formulations.

Beneficial effects of nebivolol in comparison with atenolol on safety and tolerability in essential hypertension

INTRODUCTION

Hypertension, "The silent killer" is a multifactorial disorder which is asymptomatic and if left untreated leads to lethal complications. Nebivolol is a third generation beta blocker with additional vasodilating property due to nitric oxide release.

AIM

The current study aims to assess efficacy and safety of Nebivolol and compare with Atenolol.

METHODS

This was prospective, double blind, comparative controlled clinical study. Total 90 patients were enrolled into study as per selection criteria. Patients were randomized to receive Atenolol and Nebivolol with 45 patients in each group for 12 weeks.

RESULTS AND CONCLUSION

The mean reduction diastolic blood pressure in Nebivolol and Atenolol group was 10.77±2.60 and 10.05±2.83 respectively. The number of patients with adverse effect events was higher in the Atenolol than in the Nebivolol group (36.84% of Atenolol Vs 12.82% of Nebivolol). Thus it can be concluded that, for the same antihypertensive effect, Nebivolol was better tolerated than Atenolol.

The effect of different β-blockers on vascular graft nitric oxide levels: comparison of nebivolol versus metoprolol

OBJECTIVES

The aim of this study was to investigate the effects of the vasodilating β-blocker nebivolol and the cardioselective β-blocker metoprolol on nitric oxide (NO) levels at vascular graft endothelium and vasa vasorum compared to controls in patients undergoing coronary artery bypass graft surgery.

METHODS

This was a prospective study. Fifty-five patients were divided into three groups: nebivolol group (group N, n = 23), metoprolol group (group M, n = 16), and control group (group A, n = 16). Group N received nebivolol 5 mg once daily, and group M received metoprolol 50 mg once daily for 15 days in the preoperative period. Control patients did not use β-blocker therapy. Tissue samples of both left internal mammary artery (LIMA) and saphenous vein grafts were investigated for NO activity using immunohistochemical methods.

RESULTS

Demographic characteristics and risk factors were similar between groups. We observed the highest NO activity in group N in both endothelial and vasa vasorum samples of LIMA and saphenous veins. NO activity of metoprolol group was similar to controls.

CONCLUSIONS

According to our results, we think that nebivolol may be safer and preferable in order to diminish graft spasm in patients undergoing coronary artery bypass graft surgery due to the NO-mediated vasodilating effect.

The evolving role of β-adrenergic receptor blockers in managing hypertension

β-Adrenergic blocking agents (or β-blockers) have been widely used for the treatment of hypertension for the past 50 years, and continue to be recommended as a mainstay of therapy in many national guidelines. They have also been used in a variety of cardiovascular conditions commonly complicating hypertension, including angina pectoris, myocardial infarction (MI), acute and chronic heart failure, as well as conditions like essential tremor and migraine. Moreover, they have played a primary role in controlling blood pressure in patients with these specific comorbidities and in reducing cardiovascular risk with regard to the composite outcome of death, stroke, and MI among patients younger than 60 years of age. However, in patients 60 years of age or older, β-blockers were not associated with significantly lower rates of MI, heart failure or death, and demonstrated higher rates of stroke compared with other first-line therapies. Consequently, the Canadian Hypertension Education Program recommends the use of β-blockers as first-line therapy in hypertensive patients younger than 60 years of age but not for those age 60 and older, with the exception of patients with concomitant β-blocker-requiring cardiac diseases. Several reports suggest that the lack of consistent outcome data may relate to the use of traditional β-blockers such as atenolol and their ability only to reduce cardiac output, without beneficial effect on peripheral vascular resistance. The present report will describe the clinically relevant mechanisms of action of β-blockers, their pharmacological differences, their metabolic effects, and their usefulness in patients with hypertension.

Nebivolol: impact on cardiac and endothelial function and clinical utility

Endothelial dysfunction is a systemic pathological state of the endothelium characterized by a reduction in the bioavailability of vasodilators, essentially nitric oxide, leading to impaired endothelium-dependent vasodilation, as well as disarrangement in vascular wall metabolism and function. One of the key factors in endothelial dysfunction is overproduction of reactive oxygen species which participate in the development of hypertension, atherosclerosis, diabetes, cardiac hypertrophy, heart failure, ischemia-reperfusion injury, and stroke. Because impaired endothelial activity is believed to have a major causal role in the pathophysiology of vascular disease, hypertension, and heart failure, therapeutic agents which modify this condition are of clinical interest. Nebivolol is a third-generation β-blocker with high selectivity for β1-adrenergic receptors and causes vasodilation by interaction with the endothelial L-arginine/ nitric oxide pathway. This dual mechanism of action underscores several hemodynamic qualities of nebivolol, which include reductions in heart rate and blood pressure and improvements in systolic and diastolic function. Although nebivolol reduces blood pressure to a degree similar to that of conventional β-blockers and other types of antihypertensive drugs, it may have advantages in populations with difficult-to-treat hypertension, such as patients with heart failure along with other comorbidities, like diabetes and obesity, and elderly patients in whom nitric oxide-mediated endothelial dysfunction may be more pronounced. Furthermore, recent data indicate that nebivolol appears to be a cost-effective treatment for elderly patients with heart failure compared with standard care. Thus, nebivolol is an effective and well tolerated agent with benefits above those of traditional β-blockers due to its influence on nitric oxide release, which give it singular hemodynamic effects, cardioprotective activity, and a good tolerability profile. This paper reviews the pharmacology structure and properties of nebivolol, focusing on endothelial dysfunction, clinical utility, comparative efficacy, side effects, and quality of life in general with respect to the other antihypertensive agents.

Vascular effects of nebivolol added to hydrochlorothiazide in African Americans with hypertension and echocardiographic evidence of diastolic dysfunction: the NASAA study

BACKGROUND

African Americans have greater risk of cardiovascular events than comparator populations of white European origin. A potential reason for this is reduced nitric oxide bioavailability in African Americans, resulting in increased prevalence of factors that contribute to ventricular dysfunction. We investigated the effects of nebivolol with the diuretic hydrochlorothiazide (HCTZ) in hypertensive African Americans with echocardiographic evidence of diastolic dysfunction.

METHODS

A total of 42 African American patients were assigned to nebivolol and HCTZ in an open-label fashion for a 24-week period. Changes in blood pressure (BP), echocardiographic parameters, and success in attaining target BP were determined. As an indirect determinant of endothelial function, serum total nitric oxide (NOx) levels and asymmetric dimethyl arginine (ADMA) levels were performed at baseline and after the treatment period.

RESULTS

The systolic BP decreased from 150 ± 13 to 136 ± 16 mm Hg (P < .005). Diastolic BP decreased from 94 ± 13 to 84 ± 9 mm Hg (P = .008). Of the patients that completed the study, 77% achieved a combined target BP of systolic BP <140 mm Hg and a diastolic BP <90 mm Hg. Serum NOx increased by 41% and 39% in patients that were treated with 10 mg and 20 mg daily nebivolol, respectively. The ADMA levels decreased by 44% following treatment. The change in systolic BP was strongly correlated to the change in ADMA (r = .54; P = .024). Furthermore, in comparison to a group of age-matched patients controlled with diuretic therapy only, the ADMA levels were significantly lower in the nebivolol posttreatment group (controlled BP with diuretic: 0.32 ± 0.07μmol/L; nebivolol posttreatment: 0.24 ± 0.06 μmol/L; P < .05).

CONCLUSION

Reduced BP with nebivolol in hypertensive African Americans and echocardiographic evidence of diastolic dysfunction correlates with improved endothelial function. Furthermore, improvement in endothelial function and increased nitric oxide bioavailability suggests a potential mechanism of efficacy of nebivolol in these patients.

The role of vasodilating β-blockers in patients with complicated hypertension: focus on nebivolol

Despite their proven mortality and morbidity outcomes benefits, β-blockers remain substantially underused in patients with cardiac conditions. Reluctance to prescribe β-blockers may be owing to concerns about tolerability with the traditional drugs in this class. β-blockers with vasodilatory properties, such as carvedilol and nebivolol, may overcome the tolerability and metabolic issues associated with traditional β-blockers. Because endothelial dysfunction, the pathophysiologic hallmark of hypertension, may be heightened in populations with difficult-totreat hypertension (e.g., elderly patients, African American patients), a vasodilating β-blocker may be a particularly appropriate choice for these patient groups.

Acute β-adrenergic blockade increases aortic wave reflection in young men and women: differing mechanisms between sexes

Acute β-adrenergic blockade increases aortic wave reflection; however, the mechanisms remain unclear. Evidence suggests that β-adrenergic receptor sensitivity in the peripheral vasculature differs between sexes. Therefore, the goal of this study was to examine whether β-adrenergic blockade alters aortic wave reflection to a similar extent in young men and women. In 31 subjects (16 men and 15 women; 26±1 years) noninvasive aortic pressure waveforms were synthesized from high-fidelity radial pressure waveforms via applanation tonometry before and during systemic β-blockade (0.25 mg/kg bolus, followed by 0.004 mg/kg per minute of continuous infusion of propranolol). β-Blockade increased aortic augmentation index and wave reflection amplitude (aortic augmented pressure) in both sexes (P<0.01). Although the increase in augmentation index was not significantly different between sexes (7.5±1.1% versus 4.6±1.5%; P=0.07), the increase in aortic augmented pressure was greater in women compared with men (2.8±0.5 versus 1.4±0.5 mm Hg; P<0.05). Aortic augmentation index adjusted for a heart rate of 75 bp increased in women (4.1±1.1%; P<0.05) after β-blockade, whereas it was unchanged in men (0.6±1.3%; P=0.33). Moreover, the change in aortic augmentation index was inversely associated with the change in heart rate only in men (r=-0.54; P<0.05). Our data suggest that aortic wave reflection is increased to a greater extent in women after systemic β-blockade, and enhanced aortic wave reflection appears to be mediated by a reduced heart rate in men, whereas the mechanism is unclear in women.

The role of vasodilating β-blockers in controlling arterial hypertension as a means of reducing cardiovascular and stroke risk

β-blockers have played a key role in the management of hypertension-related cardiovascular disease for decades, and continue to be recommended as a mainstay of therapy in national guidelines statements. Recent data have shown less optimal reductions in total mortality, CVD mortality, and CVD events with β-blockers compared with renin-angiotensin system-blocking agents or calcium channel blockers. The β-blocker class, however, spans a wide range of agents, and the growing concern about the risk-benefit profile of β-blockers should not be generalized to later-generation vasodilating β-blockers such as carvedilol and nebivolol. A growing database from hypertension studies confirms the clinical efficacy and safety of vasodilating β-blockers, and outcome studies indicate that these agents can play an important role in global CVD reduction in patients with hypertensive or ischemic heart failure.

Comparative long term effects of nebivolol and carvedilol in hypertensive heart failure patients

BACKGROUND

Beta-blockers improve left ventricular (LV) systolic function and prognosis in patients with chronic heart failure (CHF), but their different pleiotropic properties may influence their cardiovascular effects. This open-label study compared the effects of long-term treatment with nebivolol versus carvedilol on LV ejection fraction (LVEF), in hypertensive CHF patients. Secondary end points were to assess the effect of the 2 beta-blockers on exercise capacity and clinical outcome.

METHODS AND RESULTS

A total of 160 hypertensive CHF patients, with LVEF <40% and in New York Heart Association (NYHA) functional class I, II, or III, were randomly assigned to receive nebivolol or carvedilol for 24 months. At baseline and at the end of treatment, all patients underwent clinical evaluation, echocardiography, and 6-minute walking test. The target doses were 10 mg/d for nebivolol and 50 mg/d for carvedilol. Compared with baseline values, LVEF increased by a similar extent in the carvedilol (C) and nebivolol (N) groups (C from 36.1% (SD 1.5%) to 40.9% (SD 1.9%), P < .001; N from 34.1% (SD 1.8%) to 38.5% (SF 2.2%), P < .001). Heart rate and NYHA functional class decreased significantly in both groups, and the 6-minute walking distance increased (C from 420 m (SD 104 m) to 490 m (SD 115 m), P < .001; N from 421 m (SD 118 m) to 487 m (SD 138 m), P < .001). During 24 months, 21 carvedilol recipients (26%) and 18 nebivolol recipients (22%) had cardiac events, including 3 and 4 deaths, respectively.

CONCLUSION

In the long term, nebivolol and carvedilol appear to be similarly effective in the treatment of hypertensive patients with CHF.

The role of nitric oxide in improving endothelial function andcardiovascular health: focus on nebivolol

Although β-blockers have been endorsed by guidelines committees for the treatment of patients with hypertension, particularly those with significant CVD and high CVD risk, there are concerns about conventional β-blockers related to poorer clinical outcomes compared with other classes of antihypertensive agents, as well as deleterious effects on quality of life and lipid and carbohydrate metabolism. β-blockers comprise a heterogeneous group of antihypertensive agents, including nonselective agents, cardioselective, nonvasodilating agents, and vasodilating agents that either combine β-nonselectivity with β-blockade or possess cardioselectivity without β-blockade. The pharmacologic, mechanistic, and hemodynamic differences between conventional, nonvasodilating β-blockers and vasodilating β-blockers are discussed in this review, with a focus on the cardioselective vasodilating β-blocker nebivolol. These differences may have important clinical implications, particularly in the treatment of complicated hypertension, such as that associated with patients with diabetes or cardiometabolic syndrome, elderly patients, and African American patients, suggesting that mechanism of action may be an important consideration when choosing a β-blocker.

Clinical and economic aspects of the use of nebivolol in the treatment of elderly patients with heart failure

Heart failure is a common and disabling condition with morbidity and mortality that increase dramatically with advancing age. Large observational studies, retrospective subgroup analyses and meta-analyses of clinical trials in systolic heart failure, and recently published randomized studies have provided data supporting the use of beta-blockers as a baseline therapy in heart failure in the elderly. Despite the available evidence about beta-blockers, this therapy is still less frequently used in elderly compared to younger patients. Nebivolol is a third-generation cardioselective beta-blocker with L-arginine/nitric oxide-induced vasodilatory properties, approved in Europe and several other countries for the treatment of essential hypertension, and in Europe for the treatment of stable, mild, or moderate chronic heart failure, in addition to standard therapies in elderly patients aged 70 years old or older. The effects of nebivolol on left ventricular function in elderly patients with chronic heart failure (ENECA) and the study of effects of nebivolol intervention on outcomes and rehospitalization in seniors with heart failure (SENIORS) have been specifically aimed to assess the efficacy of beta-blockade in elderly heart failure patients. The results of these two trials demonstrate that nebivolol is well tolerated and effective in reducing mortality and morbidity in older patients, and that the beneficial clinical effect is present also in patients with mildly reduced ejection fraction. Moreover, nebivolol appears to be significantly cost-effective when prescribed in these patients. However, further targeted studies are needed to better define the efficacy as well as safety profile in frail and older patients with comorbid diseases.

The role of nitric oxide in improving endothelial function and cardiovascular health: focus on nebivolol

Although beta-blockers have been endorsed by guidelines committees for the treatment of patients with hypertension, particularly those with significant CVD and high CVD risk, there are concerns about conventional beta-blockers related to poorer clinical outcomes compared with other classes of antihypertensive agents, as well as deleterious effects on quality of life and lipid and carbohydrate metabolism. beta-Blockers comprise a heterogeneous group of antihypertensive agents, including nonselective agents, cardioselective, nonvasodilating agents, and vasodilating agents that either combine beta-nonselectivity with alpha-blockade or possess cardioselectivity without alpha-blockade. The pharmacologic, mechanistic, and hemodynamic differences between conventional, nonvasodilating beta-blockers and vasodilating beta-blockers are discussed in this review, with a focus on the cardioselective vasodilating beta-blocker nebivolol. These differences may have important clinical implications, particularly in the treatment of complicated hypertension, such as that associated with patients with diabetes or the cardiometabolic syndrome, elderly patients, and African American patients, suggesting that mechanism of action may be an important consideration when choosing a beta-blocker.

The role of vasodilating beta-blockers in patients with complicated hypertension: focus on nebivolol

Despite their proven mortality and morbidity outcomes benefits, beta-blockers remain substantially underused in patients with cardiac conditions. Reluctance to prescribe beta-blockers may be owing to concerns about tolerability with the traditional drugs in this class. Beta-blockers with vasodilatory properties, such as carvedilol and nebivolol, may overcome the tolerability and metabolic issues associated with traditional beta-blockers. Because endothelial dysfunction, the pathophysiologic hallmark of hypertension, may be heightened in populations with difficult-to-treat hypertension (e.g., elderly patients, African American patients), a vasodilating beta-blocker may be a particularly appropriate choice for these patient groups.

One size does not fit all: the role of vasodilating beta-blockers in controlling hypertension as a means of reducing cardiovascular and stroke risk

Beta-blockers have played a key role in the management of hypertension-related cardiovascular disease for decades, and continue to be recommended as a mainstay of therapy in national guidelines statements. Recent data have shown less optimal reductions in total mortality, CVD mortality, and CVD events with beta-blockers compared with renin-angiotensin system-blocking agents or calcium channel blockers. The beta-blocker class, however, spans a wide range of agents, and the growing concern about the risk-benefit profile of beta-blockers should not be generalized to later-generation vasodilating beta-blockers such as carvedilol and nebivolol. A growing database from hypertension studies confirms the clinical efficacy and safety of vasodilating beta-blockers, and outcome studies indicate that these agents can play an important role in global CVD reduction in patients with hypertensive or ischemic heart failure.

Heart rate control with adrenergic blockade: clinical outcomes in cardiovascular medicine

The sympathetic nervous system is involved in regulating various cardiovascular parameters including heart rate (HR) and HR variability. Aberrant sympathetic nervous system expression may result in elevated HR or decreased HR variability, and both are independent risk factors for development of cardiovascular disease, including heart failure, myocardial infarction, and hypertension. Epidemiologic studies have established that impaired HR control is linked to increased cardiovascular morbidity and mortality. One successful way of decreasing HR and cardiovascular mortality has been by utilizing β-blockers, because their ability to alter cell signaling at the receptor level has been shown to mitigate the pathogenic effects of sympathetic nervous system hyperactivation. Numerous clinical studies have demonstrated that β-blocker-mediated HR control improvements are associated with decreased mortality in postinfarct and heart failure patients. Although improved HR control benefits have yet to be established in hypertension, both traditional and vasodilating β-blockers exert positive HR control effects in this patient population. However, differences exist between traditional and vasodilating β-blockers; the latter reduce peripheral vascular resistance and exert neutral or positive effects on important metabolic parameters. Clinical evidence suggests that attainment of HR control is an important treatment objective for patients with cardiovascular conditions, and vasodilating β-blocker efficacy may aid in accomplishing improved outcomes.

[Advantages of vasodilating beta-blockers in congestive heart failure]

Beta-blockers play a pivotal role in the treatment of chronic systolic heart failure. However, the pharmacological family of beta-blockers is inhomogeneous regarding their pharmacological properties and their clinical effects can differ substantially according to different pharmacological properties. Because of vasodilator effects, the third generation of beta-blockers has additional potential across the cardiovascular diseases, from hypertension to heart failure. Nebivololol has both high selectivity for beta1-adrenergic receptors, no intrinsic sympathetic activity and ability to stimulate endothelial nitric oxide production. Such properties result in specific hemodynamic effects compared with others beta-blockers. Such properties also result in both high tolerability and positive metabolic effects which are crucial in high-risk groups. In the SENIORS trial, nebivolol demonstrated its efficacy and high tolerability in elderly patients with chronic heart failure irrespective of the left ventricular ejection fraction. More clinical trials would be useful to exhibit specific benefits of nebivolol in other high-risk groups of patients.

Nebivolol efficacy and safety in patients with stage I-II hypertension

BACKGROUND

Nebivolol is a novel, beta(1)-adrenergic receptor blocker with vasodilatory properties mediated through activation of the L-arginine/nitric oxide pathway.

HYPOTHESIS

This multicenter, double-blind, parallel-group, placebo-controlled study investigated the antihypertensive efficacy and safety of nebivolol in patients with stage I through stage II hypertension (sitting diastolic blood pressure [SiDBP] > or = 95 mm Hg and < or = 109 mm Hg).

METHODS

A total of 811 patients were randomized to placebo or nebivolol 5 mg, 10 mg, or 20 mg once daily for 12 weeks. The primary efficacy endpoint was the reduction in mean trough SiDBP from baseline.

RESULTS

At study end, the least squares mean reductions in trough SiDBP from baseline with nebivolol 5 mg, 10 mg, and 20 mg were - 7.8 mm Hg, - 8.5 mm Hg, and - 9.1 mm Hg, respectively, compared with - 4.6 mm Hg for placebo (P = .002 for nebivolol 5 mg, P<.001 for nebivolol 10 mg and 20 mg, vs placebo). Nebivolol treatment also produced reductions in trough sitting systolic blood pressure; however, only the 20 mg dose was statistically significant compared with placebo (-6.7 mm Hg vs - 0.4 mm Hg; P<.001). Response rates (defined as an average trough SiDBP < 90 mm Hg or a decrease by > or = 10 mm Hg from baseline at the end of the study) ranged from 66.0% to 68.9% with nebivolol 5-20 mg, compared with 49.3% with placebo (P< or =.009). Nebivolol 5 mg and 10 mg doses were well tolerated, with an overall adverse event incidence comparable to placebo.

CONCLUSIONS

Once-daily nebivolol is an effective antihypertensive agent in patients with stage I-II hypertension.

Differential effects of antihypertensive treatment on left ventricular diastolic function: an ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) substudy

OBJECTIVES

We hypothesized that an amlodipine-based regimen would have more favorable effects on left ventricular (LV) diastolic function.

BACKGROUND

Different antihypertensive therapies may vary in their effect on LV diastolic function.

METHODS

The HACVD (Hypertension Associated Cardiovascular Disease) substudy of ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) collected detailed cardiovascular phenotypic data on a subset of 1,006 participants recruited from 2 centers (St. Mary's Hospital, London, and Beaumont Hospital, Dublin). Conventional and tissue Doppler echocardiography and measurement of plasma B-type natriuretic peptide (BNP) were performed approximately 1 year after randomization to atenolol-based or amlodipine-based antihypertensive treatment to assess LV diastolic function.

RESULTS

On-treatment blood pressure (BP) (mean +/- SD) was similar in both groups: atenolol-based regimen, systolic BP of 137 +/- 17 mm Hg, diastolic BP of 82 +/- 9 mm Hg; amlodipine-based regimen, systolic BP of 136 +/- 15 mm Hg, diastolic BP of 80 +/- 9 mm Hg. Ejection fraction did not differ between groups, but early diastolic mitral annular velocity (E'), a measure of diastolic relaxation, was lower in patients on the atenolol-based regimen: atenolol-based regimen, 7.9 +/- 1.8; amlodipine-based regimen, 8.8 +/- 2.0. A measure of left ventricular filling pressure, E/E', and BNP were significantly higher in patients on the atenolol-based regimen. Differences in E', E/E', and BNP remained significant after adjustment for age and sex. Further adjustment for systolic BP, LV mass index, and heart rate had no impact on differences in mean E' or BNP. The difference in E/E' was attenuated.

CONCLUSIONS

Patients receiving treatment with an amlodipine-based regimen had better diastolic function than patients treated with the atenolol-based regimen. Treatment-related differences in diastolic function were independent of BP reduction and other factors that are known to affect diastolic function.

Current role of beta-blockers in the treatment of hypertension

IMPORTANCE OF THE FIELD

It is important to know which patients with hypertension will benefit from beta-blocker therapy and which beta-blockers should be used in the treatment of hypertension to reduce cardiovascular events and mortality.

AREAS COVERED IN THIS REVIEW

Studies between 1981 and 2009 using a Medline search are reported. Beta-blockers should be used to treat hypertension in patients with previous myocardial infarction, acute coronary syndromes, angina pectoris, congestive heart failure, ventricular arrhythmias, supraventricular tachyarrhythmias, diabetes mellitus, after coronary artery bypass graft surgery, and in patients who are pregnant, have thyrotoxicosis, glaucoma, migraine, essential tremor, perioperative hypertension, or an excessive blood pressure response after exercise.

WHAT THE READER WILL GAIN

The use of beta-blockers as first-line therapy in patients with primary hypertension has been controversial. However, the 2009 guidelines of the European Society of Hypertension state that large-scale meta-analyses of available data confirm that diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and calcium channel blockers do not significantly differ in their ability to lower blood pressure and to exert cardiovascular protection both in elderly and in younger patients.

TAKE HOME MESSAGE

The key message of this paper is that atenolol should not be used as an antihypertensive drug and that the degree of reduction of mortality, myocardial infarction, stroke and congestive heart failure by antihypertensive therapy is dependent on the degree of lowering of aortic blood pressure. Newer vasodilator beta-blockers such as carvedilol and nebivolol may be more effective in reducing cardiovascular events than traditional beta-blockers, but this needs to be investigated by controlled clinical trials.

Nebivolol in high-risk, obese African Americans with stage 1 hypertension: effects on blood pressure, vascular compliance, and endothelial function

The authors sought to determine whether nebivolol treatment results in changes in blood pressure (BP), nitric oxide bioavailability, and vascular function in obese African Americans with recently diagnosed stage 1 hypertension. Forty-three obese, hypertensive African Americans (mean BP: systolic, 148.8+/-14.3 mm Hg; diastolic, 90.4+/-8.2 mm Hg) were treated with nebivolol (5-10 mg/d) for 8 weeks. Primary outcomes were change in systolic and diastolic BP and efficacy in reaching normotensive BP. Mean systolic BP decreased by 9.2+/-14 mm Hg (P<.005) and diastolic BP decreased 6.8+/-9 mm Hg (P<.005) with 8 weeks of therapy. Significant improvements were seen in arterial compliance with nebivolol treatment as measured by aortic augmentation index (P<.005) and time to wave reflection (P=.013). Nebivolol treatment improved endothelial function as measured by flow-mediated dilation (P<.005). Levels of erythrocyte cellular superoxide dismutase increased with nebivolol, indirectly suggesting increased bioavailability of nitric oxide (P<.005). Monotherapy with nebivolol in obese, hypertensive African Americans results in significant systolic and diastolic BP reduction by mechanisms that include improved vascular function and compliance.

Simultaneous Estimation of Nebivolol Hydrochloride and Valsartan using RP HPLC

In this study, a rapid, precise, accurate, specific and sensitive ion-paired reverse phase liquid chromatographic method has been developed for the simultaneous estimation of nebivolol hydrochloride and valsartan in their capsule formulation. The chromatographic method was standardized using a HIQ sil C₁₈ column (250×4.6 mm i.d., 5 μm particle size) with UV detection at 289 nm and flow rate of 1 ml/min. The mobile phase consisting of methanol:water (80:20 v/v) with addition of 0.1 percent 1-hexanesulfonic acid monohydrate sodium salt as an ion-pairing reagent was selected. The method was validated and produced accurate and precise results for estimation of the two drugs.

Evolving mechanisms of action of beta blockers: focus on nebivolol

Beta (beta) blockers are widely used for treatment of cardiovascular and noncardiovascular diseases. Nevertheless, their mechanism of action is not fully understood and differs significantly among agents in this class. Chronic increases in adrenergic activity in heart failure result in desensitization of cardiac beta-adrenergic receptor signal transduction and adverse effects on myocytes. By reducing heart rate and decreasing myocardial workload, the pathologic remodeling of the heart may be reversed with beta-blocking agents. Among beta-blockers, there are clear differences in pharmacodynamic and pharmacokinetic properties. Newer beta-blockers differ from older agents with respect to beta-adrenoceptor affinity and selectivity and partial agonist activity, which may affect their mechanism of action and be important in clinical use.The first beta-antagonist compounds were nonselective; the next generation of beta-blockers was selective for beta1-receptors. The most recent beta-blockers may be nonselective or selective, and they have the additional ancillary property of vasodilation. Nebivolol is among the newer third-generation beta-blockers. It is unique in the class, since apart from its cardioselectivity, it also produces nitric oxide-mediated vasodilation. As a result, its hemodynamic profile is clearly different from those of traditional beta-blockers. This review will evaluate this class of agents and the basis for their differences in clinical use.