Exercise tolerance with nebivolol and atenolol

An overview of the efficacy and safety of β2-adrenoceptor antagonists for the treatment of chronic obstructive pulmonary disease

INTRODUCTION

The safety of β2-AR antagonists in the treatment of patients with COPD continues to be a topic of research and discussion within the medical community. Emerging evidence suggests potentially benefits in the management of this complex respiratory condition. However, antagonists that display a preference for β2-AR over β1-AR present a complex therapeutic challenge in COPD management, necessitating an understanding of differences in their pharmacological profiles and clinical implications.

AREAS COVERED

An overview of the mechanisms of action of β2-AR antagonists and their potential impact on respiratory function, their pharmacological interactions, clinical implications, and future perspectives in COPD.

EXPERT OPINION

β-Blockers have the potential to become a versatile class of therapeutic agents with benefits beyond their original cardiovascular use. However, the one-size-fits-all approach of prescribing β-blockers regardless of their receptor selectivity to COPD patients with concomitant heart disease may not be appropriate. Instead, it is advisable to develop an individualized treatment strategy based on a thorough assessment of the patient's overall health. The use of non selective β2-AR antagonists, functioning as inverse agonists at β2-ARs, has garnered interest and debate, but further research efforts should focus on elucidating the optimal use of β-AR antagonists in COPD, balancing cardiovascular benefits with potential respiratory risks to enhance outcomes and quality of life for individuals living with this debilitating respiratory condition.

Cardiovascular effects of doping substances, commonly prescribed medications and ergogenic aids in relation to sports: a position statement of the sport cardiology and exercise nucleus of the European Association of Preventive Cardiology

The use of substances and medications with potential cardiovascular effects among those practicing sports and physical activity has progressively increased in recent years. This is also connected to the promotion of physical activity and exercise as core aspects of a healthy lifestyle, which has led also to an increase in sport participation across all ages. In this context, three main users' categories can be identified, (i) professional and amateur athletes using substances to enhance their performance, (ii) people with chronic conditions, which include physical activity and sport in their therapeutic plan, in association with prescribed medications, and (iii) athletes and young individuals using supplements or ergogenic aids to integrate their diet or obtaining a cognitive enhancement effect. All the substances used for these purposes have been reported to have side effects, among whom the cardiovascular consequences are the most dangerous and could lead to cardiac events. The cardiovascular effect depends on the type of substance, the amount, the duration of use, and the individual response to the substances, considering the great variability in responses. This Position Paper reviews the recent literature and represents an update to the previously published Position Paper published in 2006. The objective is to inform physicians, athletes, coaches, and those participating in sport for a health enhancement purpose, about the adverse cardiovascular effects of doping substances, commonly prescribed medications and ergogenic aids, when associated with sport and exercise.

Long-term efficacy of vasodilating β-blocker in patients with acute myocardial infarction: nationwide multicenter prospective registry

BACKGROUND/AIMS

Long-term benefit of vasodilating β-blockers is unknown. This study aimed to investigate the long-term benefit of vasodilating β-blockers over conventional β-blockers in patients with acute myocardial infarction (AMI).

METHODS

Using nationwide prospective multicenter Korean Acute Myocardial Infarction Registry data, we analyzed 3-year clinical outcomes of 7,269 patients with AMI who received percutaneous coronary intervention (PCI) and β-blocker therapy. Patients were classified according to treatment strategy (vasodilating β-blockers vs. conventional β-blockers). The primary endpoint was a composite of cardiac death, myocardial infarction (MI), and hospitalization for heart failure (HF) at 3 years. Secondary outcomes were each component of the primary outcome. Propensity score matching was performed to adjust for differences of baseline characteristics.

RESULTS

In 3,079 pairs (6,158 patients) of propensity score-matched patients, the primary outcome occurred significantly less in the vasodilating β-blockers group compared with the conventional β-blockers group (7.6% vs. 9.8%, p = 0.003). Among the secondary outcomes, cardiac death occurred significantly less in the vasodilating β-blockers group than in the conventional group (3.5% vs. 4.8%, p = 0.015). The incidence rates of MI (2.4% vs. 3.0%, p = 0.160) or hospitalization for HF (2.6% vs. 3.2%, p = 0.192) were not significantly different between the two groups.

CONCLUSION

Vasodilating β-blocker therapy was associated with better clinical outcomes compared with conventional β-blocker therapy in AMI patients undergoing PCI during 3 years follow-up. Vasodilating β-blockers could be recommended preferentially for these patients.

Anti-arrhythmic therapy in athletes

The spectrum of arrhythmias that may be encountered in athletes ranges from isolated ectopic beats to ventricular tachycardia, usually in the context of a structurally normal heart. Anti-arrhythmic therapy in these individuals may be particularly challenging because of the young age, the hypervagotonic state, the desire to maintain a high physical performance, the reluctance to take medications and the need to avoid molecules included in the list of prohibited drugs of the World Anti-Doping Agency. Furthermore, the possible serious adverse effects of anti-arrhythmic drugs should be balanced against the benign nature of arrhythmias in patients with no underlying heart disease. The review summarizes the most common arrhythmias of athletes and the possible therapeutic options, including anti-arrhythmic drugs and non-pharmacological interventions. Eligibility criteria according to current guidelines are also addressed.

The Association Between β-Blocker Use and Cardiorespiratory Fitness: The Maastricht Study

Purpose:

β-Blockers (BBs) have been associated with a reduced cardiorespiratory fitness (CRF). This is possibly caused by inhibition of β2-receptors in the airways. However, there are limited data available on β-receptor selectivity and CRF. We therefore aimed to assess the association between BB use and CRF and to assess the association between β-receptor selectivity and CRF.

Methods:

Participants in the Maastricht Study were aged between 40 and 75 years. Exposure to BB use was determined by use of pharmacy records. General linear models were used to obtain adjusted means of 2 proxies for CRF: covered distance during the 6-minute walk test (6MWT) and estimated maximum power output adjusted for body mass (W_max kg⁻¹) during the submaximal cycle ergometer test. Adjusted means were compared between current, past, and never BB users. Current users were subsequently stratified by β-receptor selectivity and dose.

Results:

Compared to never use, current use was associated with a lower CRF, based on the 6MWT (current use: 569.7 m; never use: 580.4 m [P = .010]), but not based on the cycling test (current use: 2.14 W kg⁻¹; never use: 2.13 W kg⁻¹ [P = .690]). There was no difference between current selective and current nonselective BB use.

Conclusion:

β-Blockers use was associated with CRF based on the 6MWT but not the cycling test. There was no difference between current selective and nonselective BB users, possibly due to the small number of nonselective BB users, differential underlying diseases, other pharmacological properties, and limitations related to the proxies of the outcome.

β-Blockade use for Traumatic Injuries and Immunomodulation: A Review of Proposed Mechanisms and Clinical Evidence

Sympathetic nervous system activation and catecholamine release are important events following injury and infection. The nature and timing of different pathophysiologic insults have significant effects on adrenergic pathways, inflammatory mediators, and the host response. Beta adrenergic receptor blockers (β-blockers) are commonly used for treatment of cardiovascular disease, and recent data suggests that the metabolic and immunomodulatory effects of β-blockers can expand their use. β-blocker therapy can reduce sympathetic activation and hypermetabolism as well as modify glucose homeostasis and cytokine expression. It is the purpose of this review to examine either the biologic basis for proposed mechanisms or to describe current available clinical evidence for the use of β-blockers in traumatic brain injury, spinal cord injury, hemorrhagic shock, acute traumatic coagulopathy, erythropoietic dysfunction, metabolic dysfunction, pulmonary dysfunction, burns, immunomodulation, and sepsis.

Effectiveness of β-blockers in physically active patients with hypertension: protocol of a systematic review

INTRODUCTION

Based on more than 5 decades of epidemiological studies, it is now widely accepted that higher physical activity patterns and levels of cardiorespiratory fitness are associated with better health outcomes. Therefore, it is necessary to consider how treatment methods affect these two components. Clinically, one very important question concerns the influence of aerobic performance on patients being treated for hypertension. The administration of β-blockers can significantly reduce maximal-and especially submaximal-aerobic exercise capacity. The objective of this review is to determine, by comparison of existing mono and combination therapy, which β-blockers are less physically limiting for patients with hypertension who are physically active.

METHODS

A three-step strategy will be adopted in the review, following the methods used by the Joanna Briggs Institute (JBI). The initial search will be conducted using the MEDLINE and EMBASE databases. The second search will involve the listed databases for the published literature (MEDLINE, Biomedica Czechoslovaca, Tripdatabase, Pedro, EMBASE, the Cochrane Central Register of Controlled Trials, Cinahl, WoS) and the unpublished literature (Open Grey, Current Controlled Trials, MedNar, ClinicalTrials.gov, Cos Conference Papers Index, the International Clinical Trials Registry Platform of the WHO). Following the JBI methodology, analysis of title/abstracts and full texts, critical appraisal and data extraction will be carried out on selected studies using the JBI tool, MAStARI. This will be performed by two independent reviewers. If possible, statistical meta-analysis will be pooled. Statistical heterogeneity will be assessed. Subgroup analysis will be used for different age and gender characteristics. Funnel plots, Begg's rank correlation and Egger's regression test will be used to detect or correct publication bias.

ETHICS AND DISSEMINATION

The results will be disseminated by publishing in a peer-reviewed journal. Ethical assessment is not needed-we will search/evaluate the existing sources of literature.

TRIAL REGISTRATION NUMBER

CRD42015026914.

Differential effects of nebivolol vs. metoprolol on microvascular function in hypertensive humans

Use of β-adrenergic receptor (AR) blocker is associated with increased risk of fatigue and exercise intolerance. Nebivolol is a newer generation β-blocker, which is thought to avoid this side effect via its vasodilating property. However, the effects of nebivolol on skeletal muscle perfusion during exercise have not been determined in hypertensive patients. Accordingly, we performed contrast-enhanced ultrasound perfusion imaging of the forearm muscles in 25 untreated stage I hypertensive patients at rest and during handgrip exercise at baseline or after 12 wk of treatment with nebivolol (5-20 mg/day) or metoprolol succinate (100-300 mg/day), with a subsequent double crossover for 12 wk. Metoprolol and nebivolol each induced a reduction in the resting blood pressure and heart rate (130.9 ± 2.6/81.7 ± 1.8 vs. 131.6 ± 2.7/80.8 ± 1.5 mmHg and 63 ± 2 vs. 64 ± 2 beats/min) compared with baseline (142.1 ± 2.0/88.7 ± 1.4 mmHg and 75 ± 2 beats/min, respectively, both P < 0.01). Metoprolol significantly attenuated the increase in microvascular blood volume (MBV) during handgrip at 12 and 20 repetitions/min by 50% compared with baseline (mixed-model P < 0.05), which was not observed with nebivolol. Neither metoprolol nor nebivolol affected microvascular flow velocity (MFV). Similarly, metoprolol and nebivolol had no effect on the increase in the conduit brachial artery flow as determined by duplex Doppler ultrasound. Thus our study demonstrated a first direct evidence for metoprolol-induced impairment in the recruitment of microvascular units during exercise in hypertensive humans, which was avoided by nebivolol. This selective reduction in MBV without alteration in MFV by metoprolol suggested impaired vasodilation at the precapillary arteriolar level.

Aerobic Exercise and Pharmacological Therapies for Skeletal Myopathy in Heart Failure: Similarities and Differences

Skeletal myopathy has been identified as a major comorbidity of heart failure (HF) affecting up to 20% of ambulatory patients leading to shortness of breath, early fatigue, and exercise intolerance. Neurohumoral blockade, through the inhibition of renin angiotensin aldosterone system (RAS) and β-adrenergic receptor blockade (β-blockers), is a mandatory pharmacological therapy of HF since it reduces symptoms, mortality, and sudden death. However, the effect of these drugs on skeletal myopathy needs to be clarified, since exercise intolerance remains in HF patients optimized with β-blockers and inhibitors of RAS. Aerobic exercise training (AET) is efficient in counteracting skeletal myopathy and in improving functional capacity and quality of life. Indeed, AET has beneficial effects on failing heart itself despite being of less magnitude compared with neurohumoral blockade. In this way, AET should be implemented in the care standards, together with pharmacological therapies. Since both neurohumoral inhibition and AET have a direct and/or indirect impact on skeletal muscle, this review aims to provide an overview of the isolated effects of these therapeutic approaches in counteracting skeletal myopathy in HF. The similarities and dissimilarities of neurohumoral inhibition and AET therapies are also discussed to identify potential advantageous effects of these combined therapies for treating HF.

Nebivolol in preventing atrial fibrillation following coronary surgery in patients over 60 years of age

Objective

Postoperative atrial fibrillation is a common complication after cardiac surgery, with an incidence as high as 20-50%. Increased age is associated with a significant increase in postoperative atrial fibrillation risk. This common complication is associated with higher morbidity and mortality rates. The aim of this study was to assess the efficacy of nebivolol in preventing atrial fibrillation following coronary artery bypass surgery in patients over 60 years of age.

Methods

In this prospective randomized study, 200 patients who were candidates for elective coronary artery bypass surgery were divided into two groups. The first group was administered with nebivolol and the second group was administered with metoprolol. Treatment was initiated four days prior to surgery, and patients were monitored for atrial fibrillation until discharge. Forty-one patients recieved 50 mg metoprolol succinate daily, which was initiated minimum 4 days before surgery.

Results

Demographic data were similar in both groups. The incidence of postoperative atrial fibrillation in both groups was similar, with no significant difference being identified [n=20 (20%); n=18 (18%), P=0.718; respectively]. There were not any mortality at both groups during study. Inotropic agent requirement at ICU was similar for both groups [n=12 (12%), n=18 (18%), P=0.32].

Conclusion

We compared the effectiveness of nebivolol and metoprolol in decreasing the incidence of postoperative atrial fibrillation, and determined that nebivolol was as effective as metoprolol in preventing postoperative atrial fibrillation at patients. Nebivolol may be the drug of choice due to its effects, especially after elective coronary artery bypass surgery.

[Antihypertensive drug therapy : Where do we stand?]

Antihypertensive drug therapy is one of the most successful medical measures ever, at all levels. The treatment situation in Germany has clearly improved in recent years. Nowadays, a wide range of very effective and well-tolerated hypertensive substances is available. Combination therapy has a long and successful tradition in hypertensive treatment, especially with suitable fixed combinations. Furthermore, the administration of fixed combinations is very beneficial to therapy adherence because it is essentially dependent on the number of drugs to be taken. The value of beta blockers and the double blockade of the renin-angiotensin-aldosterone system are under discussion and the interpretation of corresponding studies must be conducted very carefully. The hypertensive effect of a substance cannot be comprehensively assessed without taking the time of day, the time point of measurement and the time point of intake into consideration. This is particularly important with respect to the effect over 24 h. Optimal antihypertensive therapy must also take into consideration the individual blood pressure rhythm with respect to the dose and dosing intervals. The importance of the central (aortic) blood pressure as target blood pressure will increase.

Ratings of perceived exertion at anaerobic threshold in patients with coronary artery disease

The study aimed to identify and compare the ratings of perceived exertion (RPE) at the ventilatory anaerobic threshold (VAT) in healthy subjects and patients with coronary artery disease (CAD). A total of 30 male subjects took part in the study and were divided into three groups: a control group (CG) composed of 10 healthy participants; a group composed of 10 participants diagnosed with CAD beta-blocker user (G-DACb); and a group composed of 10 participants with CAD non-beta-blocker user (G-DAC). The participants performed a cardiopulmonary exercise test (CPET) with continuous type ramp protocol to determine the VAT, through the visual graphical analysis (loss of parallelism between the oxygen uptake and the carbon dioxide output). During CPET, before the end of each one-minute period, the subjects were asked to rate dyspnea (RPE-D) and leg fatigue (RPE-L) on the Borg CR-10 scale. After the VAT was determined, the score that the participants gave on the Borg CR10 scale was verified. CG participants showed higher workload, oxygen uptake, carbon dioxide output, ventilation and heart rate at the VAT compared to the G-DAC and G-DACb (p<0.05). However, regarding the RPE-L and the RPE-D, no significant difference between the groups were observed (p<0.05). Values between five and six on Borg CR-10 scale matched the VAT in the subjects studied. However, other parameters must be concomitantly used for prescribing exercise intensity in physical training protocols, at levels close to the VAT for patients with CAD.

Nebivolol: vasodilator properties and evidence for relevance in treatment of cardiovascular disease

β-adrenergic blocking agents, a pharmacologically diverse class of cardiovascular medications, are recommended as first-line treatment for patients with hypertension and concomitant structural heart disease, and for angina and heart failure. Many within-class differences exist, from pharmacokinetics and pharmacodynamics to ancillary effects, such as intrinsic sympathomimetic activity, antiarrhythmic activity, α-1 adrenergic receptor blockade affinity, and direct vasodilation. Nebivolol is a third-generation, β1 selective, long acting β-blocker, which causes direct vasodilation via endothelium-dependent nitric oxide stimulation. The vasodilatory actions of nebivolol might result in clinical effects with some distinct properties. Differences from other β-blockers might include improvement of endothelial function, enhancement of forward flow in muscular resistance arteries, maintenance of exercise tolerance, and overall improved tolerability, side effect profile, and adherence. Nebivolol has been shown to be a clinically effective β-blocker for treatment as initial or add-on therapy for systemic hypertension, as an antianginal agent, and as therapy for patients with heart failure. These properties position nebivolol as a treatment option for patients with hypertension and/or structural heart disease, although its precise role in the therapeutic armamentarium remains to be clarified.

Differential effects of nebivolol versus metoprolol on functional sympatholysis in hypertensive humans

In young healthy humans, sympathetic vasoconstriction is markedly blunted during exercise to optimize blood flow to the metabolically active muscle. This phenomenon known as functional sympatholysis is impaired in hypertensive humans and rats by angiotensin II-dependent mechanisms, involving oxidative stress and inactivation of nitric oxide (NO). Nebivolol is a β1-adrenergic receptor blocker that has NO-dependent vasodilatory and antioxidant properties. We therefore asked whether nebivolol would restore functional sympatholysis in hypertensive humans. In 21 subjects with stage 1 hypertension, we measured muscle oxygenation and forearm blood flow responses to reflex increases in sympathetic nerve activity evoked by lower body negative pressure at rest, and during rhythmic handgrip exercise at baseline, after 12 weeks of nebivolol (5-20 mg/d) or metoprolol (100-300 mg/d), using a double-blind crossover design. We found that nebivolol had no effect on lower body negative pressure-induced decreases in oxygenation and forearm blood flow in resting forearm (from -29±5% to -30±5% and from -29±3% to -29±3%, respectively; P=NS). However, nebivolol attenuated the lower body negative pressure-induced reduction in oxygenation and forearm blood flow in exercising forearm (from -14±4% to -1±5% and from -15±2% to -6±2%, respectively; both P<0.05). This effect of nebivolol on oxygenation and forearm blood flow in exercising forearm was not observed with metoprolol in the same subjects, despite a similar reduction in blood pressure. Nebivolol had no effect on sympathetic nerve activity at rest or during handgrip, suggesting a direct effect on vascular function. Thus, our data demonstrate that nebivolol restored functional sympatholysis in hypertensive humans by a mechanism that does not involve β1-adrenergic receptors. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01502787.

Vasodilating versus first-generation β-blockers for cardiovascular protection

The utility of β-blockers in the treatment of hypertension has created much speculation as to their efficacy in patients with comorbid conditions, and there are concerns regarding their adverse metabolic effects. It is important to note that these findings were observed with traditional β-blockers, such as atenolol and metoprolol. The newer generation of β-blockers, namely carvedilol and nebivolol, is changing the manner in which β-blockers are viewed in hypertension management. Their ability to inhibit A1 adrenoreceptors and influence nitric oxide leads to vasodilation, which traditional β-blockers fail to do. These agents have been shown to have favorable metabolic effects while maintaining the beneficial cardiovascular effects of this drug class in post-myocardial infarction patients and the heart failure population.

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.

Cardio-selective beta-blocker: pharmacological evidence and their influence on exercise capacity

For the past 40 years, beta-blockers have been widely used in cardiovascular medicine, reducing morbidity as well as mortality. Beta-blockers are currently used in a number of cardiovascular conditions such as systolic heart failure, postmyocardial infarction, and in prevention and treatment of arrhythmias. They are not recommended as the first line antihypertensive therapy, particularly in the elderly, unless there are specific indications. Despite the benefits of beta-blockers, tolerability concerns in patients with co-morbidities have limited their use. Some of these problems were overcome with the discovery of cardioselective beta-blockers. The third generation beta-blockers have additional properties of vasodilatation and advantages in terms of minimizing the adverse effects of beta-blockers. Some of the advantages include improvement of insulin resistance, decrease in cholesterol as well as alleviation of erectile dysfunction. Acute treatment with beta-blockers modifies local muscular metabolic properties and impairs endurance exercise capacity whereas the influence of chronic is debated controversially.

The period between beta-blocker use and physical activity changes training heart rate behavior

The Brazilian Society of Cardiology (SBC) proposes that hypertensive subjects who use beta-blockers and practice physical exercises must have their training heart rate (HR) corrected due to the negative chronotropic effect of this drug. Nevertheless, if the physical activity is performed outside of plasmatic half-life, correction may not be necessary. This study investigated the exercise chronotropic response both inside and outside the beta-blocker plasmatic half-life. Nine subjects in use of atenolol or propranolol, and six controls, carried out three walking sessions in three days according to different schedules: EX2 (two hours after drug administration, at the plasmatic peak); EX11 (eleven hours after drug administration, at the end of plasmatic half-life); and EX23 (twenty-three hours after drug administration, outside the plasmatic half-life. The walking sessions were performed on an ergometric treadmill and HR was monitored by a heart rate monitor. During the exercises, mean HRs were 97.2, 108.4 and 109 for EX2, EX11 and EX23, respectively, with the value for EX2 statistically lower than the others (p<0.05). There were no statistical differences in the control group (p>0.05). The study concludes that the attenuation of the positive chronotropic response which occurs during exercise in subjects using beta-blockers, is less evident when the exercise is performed outside the plasmatic half-life of the drug.

Nebivolol: the somewhat-different beta-adrenergic receptor blocker

Although its clinical use in Europe dates almost 10 years, nebivolol is a beta-blocker that has been only recently introduced in the U.S. market. Like carvedilol, nebivolol belongs to the third generation of beta-blockers, which possess direct vasodilator properties in addition to their adrenergic blocking characteristics. Nebivolol has the highest beta(1)-receptor affinity among beta-blockers and, most interestingly, it substantially improves endothelial dysfunction via its strong stimulatory effects on the activity of the endothelial nitric oxide synthase and via its antioxidative properties. Because impaired endothelial activity is attributed a major causal role in the pathophysiology of hypertension, coronary artery disease, and congestive heart failure, the endothelium-agonistic properties of nebivolol suggest that this drug might provide additional benefit beyond beta-receptor blockade. Although lesser beta-blocker-related side effects have been reported in patients with chronic obstructive pulmonary disease or impotence taking nebivolol, side effects and contraindications overlap those of other beta-blockers. Clinically, this compound has been proven to have antihypertensive and anti-ischemic effects as well as beneficial effects on hemodynamics and prognosis in patients with chronic congestive heart failure. Further studies are now necessary to compare the benefit of nebivolol with that of other drugs in the same class and, most importantly, its prognostic impact in patients with hypertension.

Efficacy and tolerability of nebivolol compared with other antihypertensive drugs: a meta-analysis

BACKGROUND AND OBJECTIVE

Lowering BP to normal levels without quality of life deterioration is the most important means of reducing cardiovascular risk. Recent studies have challenged the position of beta-adrenoceptor antagonists (beta-blockers) as first-line antihypertensive drugs. Nebivolol is a third-generation, highly selective beta(1)-blocker that causes vasodilation through nitric oxide (NO) release. This meta-analysis investigates the efficacy and tolerability of nebivolol compared with other antihypertensive drugs and placebo in patients with hypertension.

METHODS

Twelve randomized controlled studies were included in which nebivolol 5 mg once daily was compared with the recommended clinical doses of other antihypertensive drugs (n = 9), placebo (n = 2), and both (n = 1). The clinical studies were selected after a MEDLINE search up to 2007 using the key words 'nebivolol' and 'hypertension.'

RESULTS

Antihypertensive response rates (the percentage of patients achieving target BP levels or a defined DBP reduction) were higher with nebivolol than with ACE inhibitors (odds ratio [OR] 1.92; p = 0.001) and all antihypertensive drugs combined (OR 1.41; p = 0.001) and similar to beta-blockers, calcium channel antagonists (CCAs) and the angiotensin receptor antagonist (ARA) losartan. Moreover, a higher percentage of patients receiving nebivolol achieved target BP levels compared with patients treated with losartan (OR 1.98; p = 0.004), CCAs (OR 1.44; p = 0.024), and all antihypertensive drugs combined (OR 1.35; p = 0.012). The percentage of patients experiencing adverse events did not differ between nebivolol and placebo; adverse event rates were significantly lower with nebivolol than losartan (OR 0.52; p = 0.016), other beta-blockers (OR 0.56; p = 0.007), nifedipine (OR 0.49; p < 0.001), and all antihypertensive drugs combined (OR 0.59; p < 0.001).

CONCLUSION

Results of previous pharmacokinetic studies suggest that nebivolol 5 mg may not conform completely to the definition of a classic beta-blocker demonstrating additional antihypertensive effect due to endothelial NO release-mediated vasodilation. This meta-analysis showed that nebivolol 5 mg achieved similar or better rates of treatment response and BP normalization than other drug classes and other antihypertensive drugs combined, with similar tolerability to placebo and significantly better tolerability than losartan, CCAs, other beta-blockers, and all antihypertensive drugs combined. Although not definitive, this meta-analysis suggests that nebivolol 5 mg is likely to have advantages over existing antihypertensives and may have a role in the first-line treatment of hypertension.

Nebivolol: pharmacologic profile of an ultraselective, vasodilatory beta1-blocker

Beta-blockers are well-established therapeutic agents in the treatment of hypertension and cardiovascular disease. However, these agents are highly heterogeneous. Beta-blockers differ in their ancillary pharmacologic properties, which are clinically important. Nebivolol is a highly selective beta(1)-adrenergic receptor blocker that induces vasodilation through stimulation of the endothelial nitric oxide/L-arginine pathway. As a racemic mixture of d- and l-enantiomers, nebivolol is highly lipophilic and rapidly absorbed. Nebivolol undergoes extensive hepatic metabolism through the cytochrome P450 2D6 (CYP2D6) system. As a result of genetic polymorphisms, CYP2D6 has variable activity, manifested by extensive and poor metabolizers of nebivolol. Time to maximum concentration is 0.5 to 2 hours, and half-life is 11 hours in extensive metabolizers; these values are about 3 times longer in poor metabolizers. Urinary and fecal excretion of unchanged nebivolol is less than 0.5% of the dose. Nebivolol has a unique hemodynamic profile of reduced systemic vascular resistance and increased left ventricular function. These properties are attributed to its vasodilating action and contrast with the hemodynamic effects of conventional beta-blockers. Nebivolol is thus a novel beta-blocker with several important pharmacologic properties that distinguish it from traditional beta-blockers. These unique properties may confer clinical benefits beyond simple blood pressure lowering.

Metabolic profile of nebivolol, a beta-adrenoceptor antagonist with unique characteristics

beta-Adrenoceptor antagonists (beta-blockers) have historically been considered an effective and safe option for first-line treatment of hypertension. However, very recently, it has been proposed that beta-blockers should no longer be considered suitable for first-line therapy in the patient with uncomplicated hypertension because of unfavourable morbidity and mortality data. New evidence from recent clinical studies of nebivolol, a third-generation highly selective beta(1)-blocker with additional endothelial nitric oxide (NO)-mediated vasodilating activity, confirms previous findings that this drug differs from other beta-blockers. The combined mechanisms of beta-adrenoceptor antagonism and NO-mediated vasodilation may potentiate the blood pressure-lowering effect of this agent, and confer a broader favourable metabolic profile, which may be clinically relevant for hypertensive patients. The antioxidant properties of nebivolol and its neutral or even favourable effects on both carbohydrate and lipid metabolism are well documented. These properties consistently differentiate nebivolol from nonvasodilating beta-blockers such as atenolol, metoprolol or bisoprolol. Therapeutic indications for beta-blockers include a wide range of co-morbidities found in hypertensive patients, including ischaemic heart disease, tachyarrhythmias and heart failure. Given that the majority of hypertensive patients require more than one drug to control blood pressure, the multiple mechanisms of action and favourable metabolic profile of nebivolol could make it an alternative therapeutic option for hypertensive patients requiring beta-adrenoceptor therapy.

Nebivolol: new therapy update

Nebivolol is a beta-blocker under U.S. Food and Drug Administration review for the treatment of hypertension. The unique pharmacologic properties of nebivolol include high specificity for the beta-1 receptor and a nitric oxide-mediated vasodilatory effect. The agent provides significant blood pressure reduction from baseline values as compared with placebo. Clinical trials have demonstrated that nebivolol reduces blood pressure similarly to atenolol, bisoprolol, amlodipine, nifedipine, lisinopril, and hydrochlorothiazide. The tolerability of nebivolol is similar to or better than that of these agents. In elderly patients (> or = 70 years of age) with clinically stable congestive heart failure, the addition of nebivolol to the treatment regimen improved the time to all-cause mortality and cardiovascular hospital admissions over that of placebo. If approved, nebivolol would likely be a viable alternative therapy for hypertension and heart failure; however, additional studies are needed in patients having coronary artery disease.

Pharmacological Mechanisms of Clinically Favorable Properties of a Selective β1-Adrenoceptor Antagonist, Nebivolol

Nebivolol is a racemic mixture of d- and l-enantiomers. The drug is characterized by beta(1)-adrenoceptor selectivity and long-acting beta-blockade exerted predominantly by d-enantiomer. Nebivolol is devoid of intrinsic sympathomimetic activity and has no relevant membrane stabilizing action. Antiproliferative properties of nebivolol were demonstrated in endothelial and smooth muscle cell cultures. Infusion of nebivolol causes a vasodilation in all vascular beds by endothelial-dependent mechanism involving stimulation of beta(3)-adrenoceptors as well as by endothelial-independent mechanism. Nebivolol possesses not only direct vasodilator properties but also augments the action of endothelium-dependent vasodilators. The antioxidant property of nebivolol can at least in part explain why treatment with this drug enhances eNOS activity and minimizes the reperfusion-induced myocardial injury. The systemic effects of nebivolol in humans have an unusual hemodynamic profile. In contrast to traditional beta-adrenoceptor antagonists, nebivolol reduces preload and afterload due to systemic vasodilation and improves arterial distensibility. At 5 mg daily nebivolol effectively reduces systolic and diastolic blood pressure over a 24-h period. During treatment with nebivolol arterial pressure follows the natural circadian rhythm. Trough-to-peak ratio for nebivolol is 0.9. It has been demonstrated in numerous placebo-controlled studies that exercise tolerance is not reduced during nebivolol therapy. By chronic administration to patients with left ventricular dysfunction nebivolol increases myocardial contractility. Nebivolol produced no significant changes in lipid levels, insulin sensitivity or glucose tolerance. These findings make nebivolol a promising therapeutic tool for the treatment of arterial hypertension and chronic heart failure.

Effect of treatment with nebivolol on parameters of oxidative stress in type 2 diabetics with mild to moderate hypertension

AIM

The aim of this study was to examine the effect of the cadioselective B(1)-adrenoceptor blocker nebivolol on glycaemic control, lipid profile and markers of oxidative stress in patients with type 2 diabetes over a 6-month period.

METHODS

Twenty-six patients with mild to moderate hypertension (140-160 mmHg systolic, 90-105 mmHg diastolic) confirmed on 24-h blood pressure monitoring, were treated with nebivolol 5 mg daily for 6 months. Total serum cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) subfractions, lipid hydroperoxides (LHPs) and total antioxidant capacity (TAC) were measured before and after 6 months of treatment.

RESULTS

Nebivolol, as expected, reduced mean daytime systolic and diastolic pressures on ambulatory monitoring (149 +/- 9 to 140 +/- 13 mmHg, P = 0.02 and 84 +/- 7 to 77 +/- 9 mmHg, P < 0.001). There were no significant changes in serum cholesterol or triglycerides following treatment but a significant increase in HDL cholesterol was noted (1.12 +/- 0.19 to 1.25 +/- 0.36 mmol/L, P = 0.008). Patients showed a highly significant reduction in TAC from 501 +/- 57 to 422 +/- 29 trolox equivalent (P < 0.001). Baseline LHPs were very high and showed no significant change over the 6-month period (18.7 +/- 7.4 and 18.7 +/- 10.9 micromol/L). The LDL score increased significantly from 1.7 +/- 0.7 to 2.3 +/- 0.7 (P = 0.0002) at 6 months suggesting a change to a more atherogenic lipid profile. Neither weight nor glycaemic control changed during treatment.

CONCLUSION

Nebivolol appears to be lipid neutral and may even have a positive effect on HDL cholesterol. Despite this it may promote the formation of potentially atherogenic LDL subfractions possibly as a result of reduced antioxidant defences. Further studies are needed to clarify the changes observed in parameters of oxidative stress.

Nebivolol

Nebivolol is a third-generation beta-adrenoceptor antagonist. It differs from other beta-adrenoceptor antagonists as it combines highly selective beta(1)-adrenoceptor antagonist properties with nitric oxide-mediated vasodilatory actions and beneficial effects on endothelial function. Nebivolol is 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 (CHF) in addition to standard therapies in elderly patients aged >or=70 years. Nebivolol is an effective antihypertensive agent and is well tolerated in patients with hypertension. The drug also effectively decreased the composite endpoint of mortality and cardiovascular hospital admission in elderly patients with CHF and was generally well tolerated in this population. Nebivolol should be considered as an alternative first-line treatment option for patients with uncomplicated mild to moderate essential hypertension and in elderly patients with CHF.

Nebivolol: novel β-blocker with nitric oxide-induced vasodilation

β-blockers have been widely used for the treatment of hypertension, congestive heart failure and angina, as well as in the post-myocardial infarction population. Both β1 selective and nonselective agents are available. Nebivolol is a new highly β1 selective antagonist with a nonadrenergic, nitric oxide potentiating vasodilatory property, which is unique among β-blockers. In addition, nebviolol does not inhibit the increase in the heart rate response to exercise, which is unique among β-blockers. Nebviolol has been tested successfully in double-blind, placebo-controlled trials in both hypertension and congestive heart failure.

Nebivolol: a review

Nebivolol is a vasodilating beta-blocker, which can be distinguished from other beta-blockers by its haemodynamic profile. It combines beta-adrenergic blocking activity with a vasodilating effect mediated by the endothelial L-arginine nitric oxide (NO) pathway. The blood pressure lowering effect of nebivolol is linked to a reduction in peripheral resistance and an increase in stroke volume and preservation of cardiac output. The effects of nebivolol have been compared with other beta-blockers and also with other classes of antihypertensive agents. In general, response rates to treatment are higher and the frequency and severity of adverse events are either comparable or lower with nebivolol. Endothelium-derived NO is important in the regulation of large arterial stiffness, which in turn is a major risk factor for cardiovascular disease. Therefore, antihypertensive drugs, such as nebivolol, that also improve endothelial function and decrease arterial stiffness, may contribute to a reduction in cardiovascular risk.

Effect of nebivolol on left ventricular function in patients with chronic heart failure: a pilot study

BACKGROUND

Sympathetic activity is a significant predictor of a poor prognosis in heart failure. Beta-blockers have been shown to improve the prognosis of patients with heart failure.

AIM

This pilot study examined the tolerability and efficacy of the new beta-blocker nebivolol on left ventricular function in patients with chronic heart failure.

METHODS AND RESULTS

Twelve patients with an ejection fraction of 13-39% were included in this double blind, placebo-controlled randomized trial of nebivolol administered in addition to standard therapy. Exercise time, heart rate, left ventricular function and tolerability were examined at baseline and after 3 months of orally administered nebivolol (2.5 and 5 mg, n = 6) or placebo (n = 6). Nebivolol was well tolerated and the NYHA class improved in four patients. Heart rate decreased while the maximal exercise duration and performance remained stable. Left ventricular function increased (ejection fraction 31.5 +/- 10.11 to 42.0 +/- 10.99%, P < or = 0.01) after 12 weeks of nebivolol. The left ventricular end-systolic diameter decreased in the nebivolol-group from 56.5 +/- 9.40 to 50.2 +/- 9.43 mm (P < or = 0.02).

CONCLUSION

These data indicate that nebivolol might improve cardiac function in patients with reduced left ventricular function.

Nitric-oxide-mediated relaxations in salt-induced hypertension: effect of chronic beta1 -selective receptor blockade

BACKGROUND

Nebivolol is a new beta1-selective adrenergic receptor antagonist with a direct vasorelaxant effect that involves activation of the l-arginine-nitric oxide (NO) pathway. Therefore, treatment with nebivolol may protect against endothelial injury in hypertension.

OBJECTIVE

To investigate whether chronic selective beta1-blockade with nebivolol could prevent endothelial dysfunction in salt-induced hypertension, and to compare it with atenolol.

METHODS

Dahl salt-sensitive rats were treated for 8 weeks with standard chow or chow containing 4% NaCl alone or in combination with nebivolol (10 mg/kg per day) or atenolol (100 mg/kg per day). Isometric tension was continuously recorded in isolated aorta and small mesenteric arteries. Constitutive NO synthase (cNOS) activity was determined by [3H]citrulline assay.

RESULTS

Chronic salt administration increased systolic blood pressure by 38 +/- 5 mmHg in salt-treated rats as compared with that in control rats. Both nebivolol and atenolol prevented a salt-induced increase in pressure. cNOS activity was significantly decreased by a high-salt diet. The impairment of endothelium-dependent relaxations in response to acetylcholine in salt-treated rats was prevented only by nebivolol, in both large and small arteries. In contrast, the reduced endothelium-independent relaxations and contractions in response to sodium nitroprusside and endothelin-1, respectively, were restored by both drugs. Nebivolol, but not atenolol, restored cNOS activity.

CONCLUSIONS

Despite nebivolol and atenolol having the same blood-pressure-decreasing effect, only nebivolol was able to prevent endothelial dysfunction. This study demonstrates for the first time that the acute NO-mediated vasodilatory action of nebivolol is also present during chronic treatment. Hence, nebivolol might become a new therapeutic tool with which to exert vascular protective effects against end-organ damage in conditions associated with NO deficiency.

Metabolic effects and safety profile of nebivolol

Nebivolol, compared with classical beta-blockers, exerts a high selectivity for beta-adrenergic receptors and also reduces peripheral vascular resistance by modulating nitric oxide (NO) release. This dual mechanism of action leads to effective control of blood pressure at a low degree of beta-blockade and explains the lack of any interference with lipid metabolism. For the same reason, the tolerability profile of nebivolol is highly favorable compared with the classical beta-blockers, with less fatigue and dyspnea in hypertensive subjects, and with an improvement of functional capacity and exercise tolerance in patients with left ventricular dysfunction. Furthermore, contrary to atenolol and propranolol, nebivolol does not diminish specific airway conductance. Compared with other first-line antihypertensive agents, nebivolol was shown to be better tolerated than nifedipine and enalapril, and to have a positive effect on general wellbeing. Among the currently available antihypertensive drugs, nebivolol therefore appears to have a most alteractive safety and tolerability profile, which can be attributed to its NO-mediated effects allowing effective control of hypertension at a lower degree of beta-blockade than with first-generation beta-blockers.

Nebivolol reverses endothelial dysfunction in essential hypertension: a randomized, double-blind, crossover study

BACKGROUND

Vascular endothelial dysfunction may predict future atherosclerosis. Hence, an antihypertensive agent that reverses endothelial dysfunction and lowers blood pressure might improve the prognosis of patients with hypertension. We hypothesized that nebivolol, a vasodilating beta-blocker, could improve endothelial dysfunction. We tested this hypothesis by comparing the effects of nebivolol and atenolol on endothelial function.

METHODS AND RESULTS

Twelve hypertensive patients with a mean ambulatory blood pressure of 154+/-7/97+/-10 mm Hg were randomized after a 2-week placebo run-in period (baseline) in a double-blind, crossover fashion to 8-week treatment periods with either 5 mg of nebivolol with 2.5 mg of bendrofluazide or 50 mg of atenolol with 2.5 mg of bendrofluazide. Forearm venous occlusion plethysmography and intra-arterial infusions of acetylcholine and N(G)-monomethyl-L-arginine (L-NMMA) were used to assess stimulated and basal endothelium-dependent nitric oxide release, respectively. Sodium nitroprusside was used as an endothelium-independent control. Nebivolol/bendrofluazide and atenolol/bendrofluazide each lowered the clinic blood pressure to the same extent (132+/-7/82+/-6 and 132+/-9/83+/-8 mm Hg, respectively; P<0.001 from baseline). The vasodilatory response to acetylcholine was significantly increased with nebivolol/bendrofluazide (maximum percentage change in forearm blood flow [mean+/-SEM], 435+/-27%, P<0.001) but not with atenolol/bendrofluazide. Similarly, the endothelium-dependent vasoconstrictive response to L-NMMA was significantly improved only with nebivolol treatment (percentage change in forearm blood flow, -54+/-5%; P<0.001). The response to sodium nitroprusside was not different between treatments, suggesting that the endothelium-independent pathway was unaffected.

CONCLUSIONS

Nebivolol/bendrofluazide increased both stimulated and basal endothelial nitric oxide release, whereas for the same degree of blood pressure control, atenolol/bendrofluazide had no effect on nitric oxide bioactivity. Thus, nebivolol may offer additional vascular protection in treating hypertension.

Nebivolol inhibits human aortic smooth muscle cell growth: effects on cell cycle regulatory proteins

An enhanced vasoconstriction and vascular smooth muscle cell proliferation are involved in pathogenesis of hypertension. Beta3-blockers are effective for treatment of hypertensive patients. Recently the new beta1-receptor blocker nebivolol showed a different hemodynamic profile from those of other classic beta-blockers. In this study we hypothesized that nebivolol may also have different effects on smooth muscle cell proliferation compared with other beta-blockers such as atenolol. Human aortic smooth muscle cells (SMCs) were cultured, and cell growth was determined by increase in cell number. Growth-signaling molecules such as mitogen-activated protein kinase (p42mapk) and S6-kinase (p70S6K) and cell-cycle regulatory proteins (i.e., Cdk2, p27Kip1, and pRb) were analyzed by immunoblotting. In cultured human aortic SMCs, cell number was markedly increased in response to 5% fetal calf serum (FCS) over 6 days (87 +/- 11 x 10(3)/well), which was inhibited by nebivolol (10(-8)-10(-5) M; 25 +/- 2 x 10(3)/well; n = 6; p < 0.05), but not by atenolol. 5% FCS activated p42mapk, S6K, and Cdk2, but downregulated p27Kip1 and hyperphosphorylated pRb. Nebivolol prevented Cdk2 activation without influencing p42mapk, S6K, pRB, and p27Kip1. Thus, the new beta1-blocker nebivolol exhibits antiproliferative effect on human SMC through inactivation of Cdk2. This effect of nebivolol may have advantages over other beta-blockers in treatment of patients with cardiovascular disease.

Effect of bisoprolol and atenolol on endurance exercise capacity in healthy men

OBJECTIVES

To compare the effects of a highly beta1-selective adrenoceptor antagonist bisoprolol with those of atenolol and placebo on endurance exercise capacity in young, healthy male volunteers.

DESIGN

Twelve subjects randomly received oral placebo, atenolol (100 mg/day) or bisoprolol (10 mg/day) for 3 weeks, following a double-blind cross-over design.

METHODS

At the end of each period, the subjects performed an endurance exercise test on the bicycle ergometer at 70% of maximal aerobic power. Cardiac output was measured by means of an automated CO2-rebreathing method. Venous blood was sampled before, during and after exercise.

RESULTS

Exercise duration was not significantly different between the two drugs tested. Total exercise duration was significantly reduced by bisoprolol (-19.4 +/- 6.7%, P< 0.01) (mean +/- SEM) and by atenolol (-29.8 +/- 6.6%, P< 0.001), compared with placebo. Atenolol and bisoprolol were equally effective in lowering resting plasma renin activity, heart rate and systolic blood pressure. Resting and exercise stroke volume were significantly increased by both drugs, so that cardiac output was not significantly affected. Both drugs induced significant decreases in plasma-free fatty acid concentrations during recovery and blunted the exercise-induced increase. There were no significant relationships between the reduction of exercise duration and the haemodynamic changes or the degree of impairment of the exercise-induced increase in free fatty acid release resulting from beta-blockade.

CONCLUSIONS

It is concluded that both drugs affect endurance exercise capacity in young, normotensive men, with a tendency to a smaller reduction during bisoprolol treatment. Haemodynamic variables are unlikely to be involved in the reduction of endurance exercise capacity. The role of the reduced availability of plasma free fatty acids remains unclear.

The vasodilator action of nebivolol in forearm vasculature of subjects with essential hypertension

AIMS

Brachial artery administration of nebivolol increases forearm blood flow in normotensive subjects through activation of the L-arginine/NO pathway. The aim of the present study was to investigate the effect of brachial artery administration of nebivolol in subjects with essential hypertension.

METHODS

We studied eight patients with uncomplicated essential hypertension and serum cholesterol less than 6.9 mmol l-1. Antihypertensive medication was discontinued 2 weeks before the study in previously treated patients. Following cannulation of the left brachial artery, saline was infused to establish baseline blood flow, followed by increasing doses of nebivolol (88.5, 177 and 354 microg min-1, each dose for 6 min), followed by saline for 12 min, followed by a 30 min infusion of L-NMMA (2 mg min-1 ). During the final 18 min of the L-NMMA infusion, nebivolol was coinfused using the same doses as before. Forearm blood flow was measured in both arms using venous occlusion plethysmography.

RESULTS

Blood flow in the noninfused arm did not change significantly throughout the study. In the infused arm blood flow increased significantly in a dose-related manner during the first series of nebivolol infusions from 2.76+/-0.39 ml min-1-1 100 ml forearm-1 during the baseline period to 4.40+/-0.60 ml min-1-1 100 ml forearm-1 (mean+/-s.e. mean, n=8, P=0.0003 by anova ). L-NMMA antagonized the vasodilator effect of nebivolol: baseline blood flow in the infused arm was 2.41+/-0.53 ml min-1 100 ml forearm-1 and 2.94+/-0.42 ml min-1 100 ml forearm-1 during coinfusion of the top dose of nebivolol with L-NMMA (P=0.0006 for an effect of L-NMMA on nebivolol response). There were no serious adverse events.

CONCLUSIONS

Nebivolol causes vasodilation in the forearm vascular bed in subjects with essential hypertension. Since this response is antagonized by L-NMMA, the vasodilatation is probably caused by activation of the L-arg/NO pathway.

Nebivolol in the management of essential hypertension: a review

Nebivolol is a lipophilic beta1-blocker. It is devoid of intrinsic sympathomimetic or membrane stabilising activity but appears to have nitric oxide-mediated vasodilatory effects. Nebivolol is administered as a racemic mixture of equal proportions of d- and l-enantiomers. The drug does not significantly influence glucose or plasma lipid metabolism and appears to have a protective effect on left ventricular function. At the recommended dosage (5 mg once daily) nebivolol reduces resting diastolic blood pressure as effectively as standard therapeutic dosages of atenolol, metoprolol, lisinopril and nifedipine, as shown in comparative trials. Nebivolol reduced blood pressure significantly more than enalapril 10 mg daily in the short but not the long term, although the enalapril dose may not have been optimal. Nebivolol has an additive effect in combination with hydrochlorothiazide. Standing blood pressure and/or mean 24-hour ambulatory blood pressure is significantly and similarly reduced with nebivolol, atenolol or nifedipine. Nebivolol tended to prevent increases in early morning blood pressure better than nifedipine. Overall response rates to nebivolol therapy (a decrease in sitting/supine diastolic blood pressure to < or = 90 mm Hg or a 10% or > or = 10 mm Hg fall in diastolic blood pressure) ranged from 58 to 81% after 4 to 52 weeks' treatment. In comparative studies, response rates were greater in nebivolol than in enalapril or metoprolol recipients, but not significantly different from those in atenolol or nifedipine recipients. Nebivolol 5 mg once daily is well tolerated in patients with hypertension. Adverse events are infrequent, transient and mild to moderate. Those reported most often include headache, fatigue, paraesthesias and dizziness. Several studies reported no signs of orthostatic hypotension with nebivolol. Comparative trials revealed no significant differences between the frequency and severity of adverse events in patients receiving nebivolol, atenolol, enalapril or placebo; however, the overall incidence of adverse events was greater with nifedipine or metoprolol. Some atenolol or enalapril, but not nebivolol, recipients reported impotence or decreased libido during therapy.

CONCLUSION

Current evidence indicates that nebivolol 5 mg once daily is a well tolerated beta-blocker, which is as effective as once daily atenolol and other classes of antihypertensive agents. It may therefore be recommended as a useful alternative first-line treatment option for the management of patients with mild to moderate uncomplicated essential hypertension.

Pharmacological properties of nebivolol in man

OBJECTIVES

The aims of the present study were to determine (1) the beta 1-blocking potency and (2) the beta 1-adrenoceptor selectivity of nebivolol in man after repeated dosing (7 days) compared with that after a single oral intake and with that after atenolol for 7 days. In addition, it was investigated whether (3) nebivolol has alpha 1-blocking properties which might at least in part explain the vasodilating property of the compound.

METHODS

Twelve healthy subjects were randomized in an open, two-way cross-over study. beta 1-Blocking potency and beta 1-adrenoceptor selectivity of nebivolol 5 mg once daily (o.d.) were compared with those of atenolol at three doses (25, 50 and 100 mg) o.d. Measurements were performed after 1 and 7 days of drug intake. beta 1-Adrenoceptor potency was assessed by the percentage decrease in exercise-induced tachycardia (delta EIT) during beta-blockade. beta 1-Selectivity of nebivolol and atenolol were investigated using the heart rate response to isoprenaline at equipotent beta 1-blocking dosages of both drugs. alpha 1-Blockade of nebivolol was measured using the phenylephrine dose-response test.

RESULTS

delta EIT after a single oral dose of nebivolol 5 mg (10%) was significantly smaller than after nebivolol 5 mg o.d. for 7 days (15%). After 1 week of treatment no difference was seen in delta EIT between nebivolol 5 mg o.d. and atenolol 25 mg o.d. (16%). At these dosages the suppression in isoprenaline-induced tachycardia by both drugs did not differ (CD20 ratio 1.7). In contrast to atenolol 25 mg, after 1 week of nebivolol 5 mg o.d., blood pressure decreased. This decrease averaged 10% and-like in a study with hypertensive patients-was similar with that after atenolol 100 mg o.d. None of the phenylephrine test parameters changed from pre-study values after nebivolol.

CONCLUSIONS

beta 1-Blockade of nebivolol 5 mg is larger after repeated dosing than after a single oral intake. After once daily repeated dosing nebivolol 5 mg and atenolol 25 mg are equipotent in beta 1-antagonism. No difference in beta 1-selectivity is observed between the two drugs. Nebivolol has no additional alpha 1-blocking property, which may at least in part explain its vasodilating effect.