Nebivolol in the management of essential hypertension: a review

Clinical pharmacokinetics of nebivolol: a systematic review

Nebivolol is a beta-1 receptor blocker used to treat hypertension, heart failure, erectile dysfunction, vascular disease, and diabetes mellitus. This review investigated the data regarding pharmacokinetic (PK) parameters, drug-drug interactions, dextrorotatory (D), and levorotatory (L) stereoisomers of nebivolol. The articles related to the PK of nebivolol were retrieved by searching the five databases; Google Scholar, PubMed, Cochrane Library, ScienceDirect, and EBSCO. A total of 20 studies comprising plasma concentration-time profile data following the nebivolol's oral and intravenous (IV) administration were included. The area under the concentration-time curve from zero to infinity (AUC0-∞) was 15 times greater in poor metabolizers (PMs) than in extensive metabolizers (EMs). In hypertensive patients, L-nebivolol expressed a higher maximum plasma concentration (Cmax) than D-nebivolol, i.e. 2.5 ng/ml vs 1.2 ng/ml. The AUC0-∞ of nebivolol was 3-fold greater in chronic kidney disease (CKD). The clearance (CL) was increased in obese than in controls from 51.6 ± 11.6 L/h to 71.6 ± 17.4 L/h when 0.5 mg/ml IV solution was infused. Nebivolol showed higher Cmax, AUC0-∞ and half-life (t1/2) when co-administered with bupropion, duloxetine, fluvoxamine, paroxetine, lansoprazole, and fluoxetine. This concise review of nebivolol would be advantageous in assessing all PK parameters, which may be crucial for clinicians to avoid drug-drug interactions, prevent adverse drug events and optimize the dosage regimen in diseased patients diagnosed with hypertension and cardiovascular disorders.

Comparison of tablet splitting techniques for dosing accuracy of nebivolol tablets: Hand splitting versus tablet cutter and knife

Tablet splitting is a common practice in clinical settings to lower doses, facilitate swallowing or save costs. Splitting devices can be used when hand splitting is difficult or painful. However, data on the accuracy of tablet splitting are limited and it presents a number of patient or formulation-related problems. Thirty nebivolol IR tablets on the Turkish market were split by hand, a tablet cutter (Rabır®) or a knife, and tested for weight variation, loss of mass, disintegration, and friability. The accuracy of split tablets was in the range of 75.4–121, 82.4–115, and 86.9–115% when split by hand, the cutter, and knife, respectively. No significant difference in accuracy was determined between the left and right sides split by the cutter (p = 0.222). The differences were significant for hand and knife splittings (p < 0.005). The precision was 9.02, 7.87, and 6.11% (CV%) for hand, tablet cutter, and knife, respectively. Only hand splitting failed to comply with the subdivision test of European Pharmacopoeia. The split portions met USP standards for friability (<1%). Splitting decreased the disintegration time (4.5 vs. 2.2 min). Overall, the accuracy of the tablet cutter was more favorable than hand splitting and knife. The study demonstrated that the splitting technique may result in inaccurate dosing and significant drug fluctuations for nebivolol tablets.

Nebivolol/valsartan combination for the treatment of hypertension: a review

Nebivolol (N) is a β₁-adrenoreceptor antagonist that is approved for treatment of hypertension in the USA. Effective treatment of hypertension is becoming an increasingly difficult process that often requires multiple drug combinations to meet target guidelines. This has resulted in the increasing introduction of multidrug single-pill combinations (SPCs) to facilitate cost and compliance issues. Some of the SPCs have added valsartan (V), an angiotensin receptor blocker, which is an increasingly advocated antihypertensive class. Pharmacological profiles of N and V, alone and combined, are well characterized. In 2007, the SPC of N and V, 5 and 80 mg, respectively, was approved by the US FDA for treatment of hypertension. This paper will summarize and update key issues in pharmacology, clinical use and benefit.

A Critical Review of Nebivolol and its Fixed-Dose Combinations in the Treatment of Hypertension

β-Adrenergic receptor blockers (β-blockers) are well-known useful and cost-effective drugs for managing hypertensive patients with coronary heart disease, stroke, and heart failure. However, it is often difficult to use β-blockers for patients with asthma or chronic obstructive pulmonary disease (COPD). Moreover, most β-blockers negatively influence glucose or lipid metabolism. Nebivolol is a third-generation lipophilic β-1 receptor-selective blocker with nitric oxide-mediated vasodilatory effects, metabolically neutral and usually well tolerated by patients with asthma or COPD. Nebivolol has significant effects of reduction in central blood pressure and improvements in endothelial dysfunction and arterial stiffness. To summarize the merits and demerits of nebivolol in different clinical situations, we conducted a review using the word 'nebivolol' on Pubmed and Embase, limiting the search to hypertension, clinical trials, and meta-analyses. This review summarizes the clinical studies on nebivolol itself and on the combination of nebivolol with other antihypertensive drugs, such as hydrochlorothiazide, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and amlodipine. Most studies showed the safety and well-tolerated profile of nebivolol and the combination of nebivolol with other antihypertensive drugs, which suggests that new fixed combinations of nebivolol with other antihypertensive drugs would be useful for patients who are unable to tolerate traditional β-blockers.

Rationale for nebivolol/valsartan combination for hypertension: review of preclinical and clinical data

To treat hypertension, combining two or more antihypertensive drugs from different classes is often necessary. β-Blockers and renin–angiotensin–aldosterone system inhibitors, when combined, have been deemed ‘less effective’ based on partially overlapping mechanisms of action and limited evidence. Recently, the single-pill combination (SPC) of nebivolol (Neb) 5 mg – a vasodilatory β1-selective antagonist/β3 agonist – and valsartan 80 mg, an angiotensin II receptor blocker, was US Food and Drug Administration-approved for hypertension. Pharmacological profiles of Neb and valsartan, alone and combined, are well characterized. In addition, a large 8-week randomized trial in stages I–II hypertensive patients (N = 4161) demonstrated greater blood pressure-reducing efficacy for Neb/valsartan SPCs than component monotherapies with comparable tolerability. In a biomarkers substudy (N = 805), Neb/valsartan SPCs prevented valsartan-induced increases in plasma renin, and a greater reduction in plasma aldosterone was observed with the highest SPC dose vs. valsartan 320 mg/day. This review summarizes preclinical and clinical evidence supporting Neb/valsartan as an efficacious and well tolerated combination treatment for hypertension.

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.

Chronic Nebivolol Treatment Suppresses Endothelin-1-Mediated Vasoconstrictor Tone in Adults With Elevated Blood Pressure

Endothelin-1 (ET-1) plays a major role in the pathophysiology of hypertension and its associated cardiovascular risk. We tested the hypothesis that chronic nebivolol treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure (BP). Furthermore, reducing ET-1 vasoconstrictor activity contributes to the improvement in endothelial vasodilator function associated with nebivolol treatment. Forty-two middle-aged adults with elevated BP (systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg) completed a 3-month, double-blind, randomized, placebo controlled trial: 14 received nebivolol (8 men/6 women; 5 mg per day); 14 received metoprolol succinate (9 men/5 women; 100 mg per day); and 14 received placebo (9 men/5 women). Forearm blood flow (plethysmography) responses to selective (BQ-123: 100 nmol/min; 60 minutes) and nonselective (BQ-123+BQ-788 [50 nmol/min]; 60 minutes) ET-1 receptor blockade, as well as acetylcholine (4.0, 8.0, and 16.0 μg per 100 mL of tissue per minute) in the absence and presence of nonselective ET-1 receptor blockade were determined before and after each treatment intervention. Forearm blood flow responses to BQ-123 and BQ-123+BQ-788 were similarly and significantly elevated (≈30% and 60%, respectively) from baseline in all 3 groups. Nebivolol, but not metoprolol or placebo, therapy resulted in a marked (≈25% and 45%; P<0.05) reduction in forearm blood flow response to BQ-123 and BQ-123+BQ-788. Moreover, after nebivolol therapy only, vasodilator response to acetylcholine was not significantly increased by ET-1 receptor blockade. These results demonstrate that nebivolol, but not metoprolol, treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated BP. In addition, nebivolol-induced reduction in ET-1-mediated vasoconstrictor tone underlies the favorable effects of this β-blocker on endothelial vasodilation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01395329.

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.

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.

A pharmacokinetic drug interaction study between nebivolol and paroxetine in healthy volunteers

WHAT IS KNOWN AND OBJECTIVE

Nebivolol is a highly selective beta-blocker with additional vasodilator properties, widely used in the clinical practice for the treatment of hypertension and heart failure. Paroxetine is a second-generation antidepressant and a potent inhibitor of CYP2D6, the same isoenzyme involved in the metabolism of nebivolol. The objective of this study was to investigate the effect of multiple-dose paroxetine intake on the pharmacokinetics of nebivolol in healthy volunteers and its potential consequences upon nebivolol pharmacodynamics.

METHODS

The study included 23 healthy subjects and was designed as an open-label, single-centre, non-randomized, two-period clinical trial. During period 1 (reference), each volunteer received a single dose of 5 mg nebivolol, whereas during period 2 (test), each volunteer received a single dose of 5 mg nebivolol and 20 mg paroxetine, after a pretreatment regimen with paroxetine (20-40 mg/day for 6 days). The pharmacokinetic parameters of nebivolol and its active metabolite were analysed by non-compartmental modelling. The pharmacodynamic parameters (blood pressure and heart rate) were assessed at rest, after each nebivolol intake.

RESULTS AND DISCUSSION

Pretreatment with paroxetine increased the mean peak plasma concentrations (Cmax ) for unchanged nebivolol (1·78 ± 1·17 vs. 4·24 ± 1·67 ng/mL) and for its active metabolite (0·58 ± 0·21 vs. 0·79 ± 0·24 ng/mL) compared to nebivolol alone. The time (tmax ) to reach Cmax was 1·37 ± 0·88 (h) and 3·11 ± 1·76 (h) for the parent compound and its active metabolite after nebivolol administered alone and 3·96 ± 1·76 (h), respectively, 7·33 ± 7·84 (h) after pretreatment with paroxetine. Also, the total areas under the curve (AUC0-∞ ) were significantly increased from 17·26 ± 43·06 to 106·20 ± 65·56 h ng/mL for nebivolol unchanged and 13·03 ± 11·29 to 74·56 ± 88·77 h ng/mL for its hydroxylated metabolite, before and after paroxetine intake. All the pharmacokinetic parameters presented statistically significant differences when paroxetine was administered with nebivolol. Nonetheless, statistical analysis did not show a significant difference between the vital signs measured during the two periods.

WHAT IS NEW AND CONCLUSION

After pretreatment with paroxetine, the exposure to nebivolol was increased by 6·1-fold for the parent drug and 5·7-fold for the hydroxylated active metabolite. Paroxetine influenced nebivolol pharmacokinetics in healthy volunteers, but it did not have a significant effect on nebivolol pharmacodynamic parameters measured at rest, although the clinical relevance of this drug interaction needs further investigation.

No evidence of nitrate tolerance caused by nebivolol

BACKGROUND

Continuous long-term treatment with nitrates may cause nitrate tolerance. Nebivolol is a highly selective beta1-adrenergic antagonist with additional nitric oxide (NO)-mediated vasodilatory effects. However, there have been no investigations into whether or not the long-term administration of nebivolol might cause nitrate tolerance.

METHODS

We performed a randomized, double-blind, placebo-controlled, cross-over study in 16 healthy men. Subjects received 5 mg nebivolol or placebo once daily for 8 days in random order divided by a drug-free interval of 2 weeks. Forearm blood flow (FBF) was measured by venous occlusion plethysmography 3 h after oral intake of the first and last doses of nebivolol and placebo, respectively. FBF was measured again following the intravenous administration of 4 μg nitroglycerin/kg body weight/min for 5 min.

RESULTS

Following 8 days of continuous intake of placebo, nitroglycerin increased FBF by 54% (p < 0.05), whereas nitroglycerin increased FBF by 96% (p < 0.01) following 8 days of continuous intake of nebivolol, and the increase after 8 days of nebivolol was significantly (p < 0.05) more pronounced than after 8 days of placebo.

CONCLUSIONS

These findings indicate no evidence of nitrate tolerance caused by long-term administration of nebivolol. On the contrary, long-term intake of nebivolol increases rather than decreases the NO-mediated vasodilating effects.

Both carvedilol and nebivolol may improve platelet function and prothrombotic state in patients with nonischemic heart failure

It is unclear whether carvedilol and nebivolol will produce different effects on platelet function and prothrombotic state in heart failure (HF). Thus, we compared their effects on these functions in patients with nonischemic HF. We included 61 patients with symptomatic nonischemic HF having ejection fraction ≤40%. The patients were randomized to carvedilol (n = 31) or nebivolol (n = 30). Analyses were made at baseline, 3, and 6 months. At 6 months, mean platelet volume (MPV) was significantly lowered by both carvedilol and nebivolol therapy. However, MPV tended to be lower in the carvedilol group (7.7 ± 1.0 vs 8.0 ± 0.7 fL, P = .05). Fibrinogen and d-dimer levels were significantly decreased in but comparable in both the groups. Carvedilol and nebivolol have similar beneficial effects on platelet function and prothrombotic state in patients with nonischemic HF.

The effect of valsartan and nebivolol treatment on ADMA and pentraxin-3 levels in hypertensive patients

Long pentraxin 3 (PTX3) is a recently discovered multimeric inflammatory mediator that is structurally linked to short pentraxins, such as C-reactive protein (CRP) and serum amyloid P component. PTX3 is produced by a variety of tissues and cells, including vascular endothelial cells and macrophages. Because of its extrahepatic synthesis (in contrast to CRP), the PTX3 level is believed to be a true independent indicator of disease activity because PTX3 is produced at sites of inflammation and is intimately linked to endothelial dysfunction. PTX3 also has key functions in innate immunity and has been identified in atherosclerotic lesions. Previously, PTX3 was associated with myocyte damage in myocardial infarction (MI), mortality after MI, and unstable angina. Because PTX3 release is likely a specific response to vascular damage, PTX3 levels may provide more explicit information on development and progression of atherosclerosis than nonspecific markers like CRP and interleukin-6. Asymmetric dimethylarginine (ADMA) is a naturally occurring component of human blood plasma. More than one decade ago ADMA was first reported to exert biological effects by inhibiting nitric oxide synthesis. Many researchers today agree that ADMA may play a prominent role in the pathogenesis and in the progression of cardiovascular diseases. In this study PTX3 and ADMA levels investigated of valsartan and nebivolol's effect on newly diagnosed hypertensive patients.

Predictors of switching from beta-blockers to other anti-hypertensive drugs: a review of records of 19,177 Chinese patients seen in public primary care clinics in the New Territory East, Hong Kong

BACKGROUND

Beta-blocker drugs are commonly used in family practice and studies showed that they were the most popularly prescribed medications among all antihypertensive agents. This study aimed to identify the factors associated with medication switching from a beta-blocker to another antihypertensive drug among Chinese patients.

METHODS

We used a validated database which consisted of the demographic and clinical information of all Chinese patients prescribed a beta-blocker from any public, family practice clinics between 01 Jan 2004 to 30 June 2007 in one large Territory of Hong Kong. The proportion of patients switched from beta-blockers to another antihypertensive agent 180 days within their first prescription was studied, and the factors associated with medication switching were evaluated by using multivariate regression analyses.

RESULTS

From 19,177 eligible subjects with a mean age of 59.1 years, 763 (4.0%) were switched from their beta-blockers within 180 days of commencing therapy. A binary logistic regression model used medication switching as the outcome variable and controlled for age, gender, socioeconomic status, clinic setting (general out-patient clinics, family medicine specialist clinic or staff clinics), district of residence, visit type (new vs. follow-up attendance), the number of concomitant co-morbidities, and the calendar year of prescription. It was found that older patients (age 50-59 years: adjusted odds ratio [AOR] 1.38, 95% C.I. 1.12-1.70; p = 0.002; age 60-69 years: AOR 1.63 95% C.I. 1.30-2.04, p < 0.001; age ≥ 70 years: AOR 1.82, 95% C.I. 1.46-2.26, p < 0.001; referent age < 50 years) and new visitors (AOR 0.57, 95% C.I. 0.48-0.68, p < 0.001) were more likely to have their medication switched.

CONCLUSIONS

Closer monitoring of the medication taking behavior among the older patients and the new clinic visitors prescribed a beta-blocker is warranted. Future studies should evaluate the reasons of drug switching.

Reversal of subclinical left ventricular dysfunction by antihypertensive treatment: a prospective trial of nebivolol against metoprolol

OBJECTIVES

To assess the effects of antihypertensive treatment on subclinical left ventricular dysfunction and to compare the effects of nebivolol with metoprolol.

METHODS

This is a prospective, randomized, parallel, active-controlled, PROBE design study (ClinicalTrials.org: NCT00942487) in 60 patients (53±9 years, 67% men) with arterial hypertension, left ventricular hypertrophy, normal ejection fraction, and no coronary heart disease, randomized to either a nebivolol-based or a metoprolol-based treatment, who had conventional and tissue Doppler echocardiography, at rest and during dobutamine stress, at baseline and after 6 months.

RESULTS

SBP and DBP, and resting heart rate decreased by 13, 13, and 12%, respectively, on nebivolol, and by 11, 13, and 7%, respectively, on metoprolol (all, P<0.01). Mean longitudinal early diastolic velocity increased by 16% (P<0.05) on nebivolol compared with 9% (P=not significant) on metoprolol (P=not significant for intergroup differences), whereas flow propagation velocity increased by 34% on nebivolol (P<0.05) and did not change on metoprolol (P<0.01 for intergroup differences). Mean longitudinal displacement increased by 10% on nebivolol (P<0.05) and did not change on metoprolol (P<0.05 for intergroup differences), whereas ejection time increased by 5% on nebivolol (P<0.05) and did not change on metoprolol. All the other parameters of left ventricular function were not different between the two treatment arms.

CONCLUSION

Patients with mild-to-moderate hypertension have a beneficial effect from 6-month antihypertensive treatment on diastolic longitudinal left ventricular function; effects are significant with nebivolol, but not with metoprolol.

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.

A comparative study of nebivolol and (S) atenolol on blood pressure and heart rate on essential hypertensive patients

Objectives:

To study the effect of nebivolol 5 mg once daily versus (S)-atenolol 25 mg once daily in patients with essential hypertension.

Materials and Methods:

A prospective study was conducted at RLJH and Research Centre which included 30 patients in each group with essential hypertension. The sex, age, presenting illness, and family history of the patients were recorded. Investigations such as blood sugar, urine analysis, kidney function test, lipid profile, and ECG were performed before starting the treatment. Any adverse effects during the treatment were noted. Blood pressure and heart rate were recorded at baseline and during follow-up. One group received nebivolol 5 mg once daily and other group (S)atenolol 25 mg once daily. Patients were followed-up every 15 days for 3 months.

Results:

Nebivolol group had 18 males and 12 females with mean age 50.6 ± 9.5 years, (S)-atenolol had 16 males and 14 females with mean age 54.4 ± 9 years. Patients receiving nebivolol and (S)-atenolol showed a significant fall (P <·0001) in systolic (SBP), diastolic blood pressure (DBP), and heart rate at the end of first, second, and third month when compared to baseline. The difference in fall in SBP and DBP was insignificant between the groups, but fall in heart rate was significant (P <·0001). Adverse effects such as headache, dizziness, and fatigue were reported with both drugs.

Conclusion:

Reduction of blood pressure with nebivolol and (S)atenolol was similar, but fall in blood pressure from baseline was highly significant in both groups.

Comparison of the effects of nebivolol and valsartan on BP reduction and sleep apnoea activity in patients with essential hypertension and OSA

OBJECTIVES

To investigate the effect of nebivolol, a third generation beta-blocker, on blood pressure (BP) reduction and polysomnographic parameters in hypertensive patients with mild-to-moderate obstructive sleep apnoea (OSA).

METHODS

In this double-blind, parallel group study, patients were randomized to nebivolol 5 mg or valsartan 80 mg once daily following a 14-day, placebo run-in period during which any antihypertensive medication were discontinued. BP and heart rate measurements and overnight polysomnography were performed at baseline and after 6 weeks of treatment. Safety and tolerability were assessed.

RESULTS

Thirty-one patients were randomized to nebivolol (n = 16) or valsartan (n = 15). After six weeks both systolic and diastolic BP were effectively reduced by both treatments. Reductions in BP were not statistically significant different between agents, but mean heart rate was significantly decreased with nebivolol (compared with valsartan (p < 0.001). There was no statistically significant difference between both treatments for the change from baseline to treatment end for mean (+/-SD) Apnoea Hypopnoea Index (AHI) (nebivolol: 23.0 +/- 9.2 to 27.9 +/- 21.2 events/h; valsartan: 23.8 +/- 6.6 to 22.5 +/- 18.0 events/h; p = 0.48) or for any other sleep-related parameters. Both agents were well tolerated.

CONCLUSION

Nebivolol has a significant BP reduction effect in patients with OSA that is similar to valsartan and reduces heart rate to a greater extent which may prove beneficial in selected 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.

Pulmonary effects of nebivolol

The pharmacological control of arterial hypertension is a very frequent issue in clinical practice and some critical aspects can arise in particular circumstances and with particular molecules. In the case of hypertensive subjects with respiratory comorbidities, when first introduced, these beta-adrenergic receptor antagonists were described as affecting airway patency as a result of their antagonism against beta(2)-adrenergic receptors within airway muscles. New molecules with a better respiratory tolerability were subsequently designed in order to overcome the narrow therapeutic window of first-generation beta-adrenergic receptor antagonists. Nebivolol is a third-generation beta-adrenergic receptor antagonist with high beta(1)-selective adrenergic receptor antagonism and vasodilating properties that induces a substantial decrease of arterial pressure in hypertensive subjects while preserving their left ventricular function. Respiratory effects of nebivolol have been investigated in animal models, in healthy volunteers and in clinical trials carried out on patients suffering from bronchial asthma and chronic obstructive pulmonary disease (COPD). In contrast to older compounds, nebivolol, which modulates the endogenous production of nitric oxide and affects oxidative cascade, proved clinically well tolerated in terms of respiratory outcomes in this type of subject. Moreover, due to the substantial dissociation between its cardiac and pulmonary activity, nebivolol confirmed a very good safety profile when regularly administered to hypertensive subjects with obstructive respiratory comorbidities.

Recent Advances in Pharmacotherapy

Many unique and clinically important medications were approved by the Food and Drug Administration from December 2007 through May 2008 for various conditions encountered in an internal medicine setting. These new treatments dramatically vary in their targeted body system and include agents for the cardiovascular system (nebivolol), central nervous system (desvenlafaxine), gastrointestinal tract (certolizumab, methylnaltrexone, and alvimopan), immunological function (etravirine), and metabolic function (sapropterin). This article discusses medications by their respective body system. Each review is comprised of an overview of the Food and Drug Administration–approved indication and the drug’s role in treatment of that disease state. Current dosing guidance, clinical efficacy and clinically relevant adverse drug reactions, drug interactions, contraindications, and precautions are also presented. This review is designed to focus on the new molecular entities and biological approvals clinicians may potentially encounter in an internal medicine practice.

Differential effects of nebivolol and atenolol on transmitral diastolic filling parameters in patients with essential hypertension

INTRODUCTION

Impaired left ventricular (LV) diastolic relaxation, detected by pulsed Doppler echocardiography, is predictive of a higher incidence of major cardiovascular events in hypertensive patients. An improvement in LV diastolic function is an important goal of treatment. However, treatment of LV diastolic dysfunction remains empirical. The objective of our study was to compare the short-term effects of nebivolol and atenolol on Doppler diastolic filling parameters in hypertensive patients.

METHODS

A total of 32 patients with mild-to-moderate hypertension were enrolled in the study. The patients were randomly assigned to receive treatment with either nebivolol (5 mg/day) or atenolol (50 mg/day) for 1 month. Diastolic filling parameters, with pulsed-wave Doppler transmitral flow velocities, were measured 1 day before and 1 month after treatment.

RESULTS

Compared with baseline, both agents significantly decreased heart rate and blood pressure. However, there was no significant difference in pre-and post-treatment values between the nebivolol and atenolol groups. Both drugs significantly improved LV transmitral flow measured by early diastolic flow/atrial contraction signal (E/A) ratio, decreased deceleration time (DT) and isovolumetric contraction time (IVRT), but post-treatment improvement in E/A, DT and IVRT values was more significant with nebivolol compared with atenolol (P=0.05, P=0.05 and P=0.003, respectively).

CONCLUSIONS

Although treatment with nebivolol or atenolol results in improved LV transmitral diastolic function filling parameters (E/A ratio, IVRT and DT), nebivolol has a greater effect compared with atenolol in patients with mild-to-moderate hypertension.

Nebivolol and metoprolol for treating migraine: an advance on beta-blocker treatment?

OBJECTIVE

To evaluate the efficacy of oral treatment with nebivolol and metoprolol in the prophylaxis of migraine attacks.

BACKGROUND

Beta-blockers such as propranolol and metoprolol are known to be effective in preventing migraine attacks. Following earlier observations of successful use of nebivolol in a few hypertensive patients with concomitant migraine, we conducted a prospective study to ascertain whether nebivolol would be effective and better tolerated, in a methodologically strict, randomized and double-blind setting.

DESIGN AND METHODS

Randomized, double-blind study in 30 patients with confirmed migraine diagnosis, a minimum 1-year history, onset prior to 50 years of age, written records of attacks for the previous 3 months, and minimum 2 attacks per month. Primary endpoint was frequency of attacks (prevention of migraine attacks) in the final 4 weeks of a 14-week treatment on full dose of metoprolol and nebivolol. Secondary endpoints were time to therapeutic effect, duration of attacks, intensity of headache, consumption of analgesics, evaluation of accompanying symptoms, migraine disability assessment, clinical global impression, quality of life, and responder rates. The statistical analysis was prospectively planned and conducted for all randomized patients.

RESULTS

Both metoprolol and nebivolol where similarly effective regarding the main endpoint (prevention of migraine attacks) as well as the secondary ones, and both had a fast onset of action, typically within 4 weeks from starting therapy, with responder rates increasing relatively little over time after the first 4 weeks. Use of acute pain medication decreased on both drugs, as well as accompanying symptoms. Both patients' and physicians' evaluations of disability and disease status were similarly favorable to the 2 treatments. Regarding safety, nebivolol was considerably better tolerated than metoprolol in terms of all reported events, treatment-related events, and event severity.

CONCLUSIONS

Our results suggest that nebivolol is as effective as metoprolol in the prophylaxis of migraine attacks, with the advantages of being better tolerated and not requiring up-titration to achieve therapeutic levels. Further and larger trials should be conducted on nebivolol in the prevention of migraine attacks as it may provide an improvement in current migraine prophylaxis with beta-blockers.

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.

The efficacy and tolerability of nebivolol in hypertensive African American patients

Hypertensive African Americans often respond poorly to beta-blocker monotherapy, compared with whites. There is evidence, however, that suggests that this response may be different if beta-blockers with vasodilating effects are used. This 12-week, multi-center, double-blind, randomized placebo-controlled study assessed the antihypertensive efficacy and safety of nebivolol, a cardioselective, vasodilating beta1-blocker, at doses of 2.5, 5, 10, 20, or 40 mg once daily in 300 African American patients with stage I or II hypertension (mean sitting diastolic blood pressure [SiDBP] > or =95 mm Hg and < or =109 mm Hg). The primary efficacy end point was the baseline-adjusted change in trough mean SiDBP. After 12 weeks, nebivolol significantly reduced least squares mean SiDBP (P< or =.004) at all doses of 5 mg and higher and sitting systolic blood pressure (P< or =.044) at all doses 10 mg and higher, compared with placebo. The drug was safe and well-tolerated, with no significant difference in the incidence of adverse events compared with placebo. Nebivolol monotherapy provides antihypertensive efficacy, with few significant adverse effects, in hypertensive African Americans.

Nebivolol induces a hyperpolarizing effect on smooth muscle cells in the mouse renal artery by activation of beta-2-adrenoceptors

Nebivolol is a highly selective beta(1)-adrenoceptor antagonist with vasodilator properties involving the vascular endothelium, but its effect on the smooth muscle cells (SMC) is still unclear. In this paper, we tested the effect of nebivolol on renal artery smooth muscle cells and investigated the cellular mechanism involved. To this purpose, the denuded renal arteries isolated from mice were studied in vitro using the myograph and the nitric oxide (NO) sensor techniques, while the SMC in culture were analyzed by the patch-clamp technique. The myograph technique was used to assay the vasodilator effect of nebivolol on the arterial muscular layer, and to establish the optimal dose of the drug to be tested on single SMC by the patch-clamp technique. Using both the myograph and the patch-clamp techniques, we examined the potential contribution of beta(2)-adrenoceptors and Ca(2+)-activated K(+) channels to the nebivolol-induced effects, by exposing the denuded arteries and SMC cultures to specific inhibitors such as butoxamine (100 micromol/l), tetraethylammonium (TEA, 1 mmol/l), and iberiotoxin (100 nmol/l). The direct measurement of NO using the NO sensor enabled us to evaluate if nebivolol induces/or not the release of NO in denuded renal arteries. The results of this study show that nebivolol exerts vasodilator effects on the SMC in the denuded renal arteries and the maximal response is achieved at a concentration of 50 micromol/l. Nebivolol effects involve binding to the beta(2)-adrenoceptors and the subsequent activation of Ca(2+)-activated K(+) channels in SMC, with no contribution of NO. Taken together, the study brings new insights into the mechanism underlying the nebivolol-induced arterial vasodilation.

A Randomized, Double-Blind, Placebo-Controlled Parallel-Group Study to Assess the Efficacy and Safety of Nebivolol, a Novel β-Blocker, in Patients With Mild to Moderate Hypertension

This double-blind, multicenter, randomized placebo-controlled study evaluated the antihypertensive efficacy and safety of nebivolol, a selective beta1-adrenoreceptor blocker with vasodilating effects, in patients with mild to moderate hypertension (sitting diastolic blood pressure [SiDBP] > or =95 mm Hg and < or =109 mm Hg). A total of 909 patients were randomized to receive placebo or nebivolol 1.25, 2.5, 5, 10, 20, or 40 mg once daily for up to 84 days. The primary end point was the change in trough SiDBP from baseline to study end. Nebivolol significantly reduced trough SiDBP (8.0-11.2 mm Hg compared with 2.9 mm Hg with placebo; P<.001) and trough sitting systolic blood pressure (a 4.4-9.5-mm Hg decrease compared with a 2.2-mm Hg increase [corrected] with placebo; P< or =.002). The overall adverse event experience was similar in the nebivolol (46.1%) and placebo (40.7%) groups (P=.273). Once-daily nebivolol is an effective antihypertensive in mild to moderate hypertensive patients.

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: third-generation β-blockade

Nebivolol is a third generation beta-blocker. It is highly selective for the beta1-adrenoceptor, and has additional nitric oxide-mediated vasodilating and antioxidant properties, along with a favourable metabolic profile. Nebivolol is well tolerated by patients with hypertension and heart failure. Although several smaller studies were conducted with nebivolol in hypertensive patients, no large randomised clinical trials have been performed to prove efficacy on hard clinical end points. In patients with heart failure, a large mortality/morbidity trial was conducted, and nebivolol was shown to reduce the composite end point of mortality and hospitalisations. Nebivolol is registered, in Europe, for mild-to-moderate, uncomplicated hypertension and mild-to-moderate heart failure; and outside Europe, for hypertension. This review describes experimental and clinical data regarding this selective beta-blocker with vasodilating and antioxidant effects.

Nebivolol: a novel beta-blocker with nitric oxide-induced vasodilatation

Nebivolol is a novel beta₁-blocker with a greater degree of selectivity for beta₁-adrenergic receptors than other agents in this class and a nitric oxide (NO)-potentiating, vasodilatory effect that is unique among beta-blockers currently available to clinicians (nebivolol is approved in Europe and is currently under review in the US). A NO-potentiating agent such as nebivolol may have an important role in hypertensive populations with reduced endothelial function such as diabetics, African-Americans and those with vascular disease. Nebivolol is a racemic mixture with beta-blocker activity residing in the d-isomer; in contrast, l-nebivolol is far more potent in facilitating NO release. Nebivolol is unique among beta-blockers in that, at doses <10 mg, it does not inhibit the increase in heart rate normally seen with exercise. The efficacy of nebivolol has been tested successfully in clinical trials against other agents including other beta-blockers, angiotensin-converting enzyme-inhibitors and calcium channel antagonists in patients with hypertension, angina, and congestive heart failure. The tolerability of nebivolol has been shown to be superior to that of atenolol and metoprolol. In controlled clinical trials, nebivolol has a side effect profile that is similar to placebo, in particular as it relates to fatigue and sexual dysfunction. This article will review published clinical data regarding this cardioselective beta-blocker.

Effects of nebivolol on platelet activation in hypertensive patients: A comparative study with metoprolol

OBJECTIVES

We evaluated the effects of nebivolol on platelet activation in hypertensive patients by measuring mean platelet volume (MPV) and plasma soluble P-selectin (sP-sel) levels and compared with those of the patients taking metoprolol.

MATERIALS AND METHODS

Eighty newly diagnosed hypertensive patients in grade 1 hypertension were enrolled in this prospective, blinded randomized study. Seventy two patients completed the study. After baseline assessment, each patient was randomly allocated to 5 mg daily dose of nebivolol (n=37, 20 male) or 100 mg daily dose of metoprolol (n=35, 18 male) and treated for 6 months. Blood pressure, heart rate, lipid profile, plasma glucose, sP-selectin levels, platelet counts and MPV were measured before and after treatment.

RESULTS

At the end of 6 months, nebivolol significantly decreased MPV and plasma sP-selectin levels (7.59+/-0.78 fl vs. 7.42+/-0.74 fl, p<0.001; 1.29+/-0.46 ng/ml vs. 1.21+/-0.36 ng/ml, p=0.002, respectively) compared to those of pretreatment. Although pretreatment sP-selectin levels of the two groups were similar, posttreatment plasma sP-selectin levels were significantly reduced with nebivolol compared with those of metoprolol group (1.21+/-0.36 ng/ml vs. 1.46+/-0.30 ng/ml, p=0.008). In contrast, metoprolol treatment did not cause any significant change in platelet activation parameters after treatment.

CONCLUSION

Beneficial effects of nebivolol on platelet activation were more potent than those of metoprolol. We consider that decreased platelet activation with nebivolol might play a role to reduce thrombotic risk in hypertensive patients.

Beta blockers in the management of chronic kidney disease

The sympathetic nervous system modulates renal function through its receptors namely beta1 (cardiac output and renin release), alpha1 (systemic and renovascular constriction), and beta2 renovascular dilation. Sympathetic overactivity is commonly seen in chronic kidney disease (CKD) and is an important contributor to increasing the risk of cardiovascular events as well as increasing renal disease progression. Recent evaluations of drug use in people with CKD shows a remarkably low percentage of patients receiving beta-blockers, especially in more advanced stage CKD when cardiovascular risk is higher. This is in large part due to tolerability of these agents. Moreover, water-soluble beta-blockers such as atenolol and metoprolol are dialyzable and require supplementation to avoid exacerbation of arrhythmias following dialysis. Newer vasodilating beta-blockers have better tolerability and different effects on renal hemodynamics as well as metabolic variables. These effects are related to the relative alpha1-blocking effect of agents such as carvedilol and labetolol, with carvedilol having relatively greater alpha-blocking effects. Few studies evaluate beta-blockers on cardiovascular risk in CKD patients. Studies with carvedilol demonstrate attenuated increases in albuminuria as well as reduction in cardiovascular events in CKD patients with hypertension. This paper reviews the animal and clinical trial data that evaluate beta-blockers in CKD highlighting the vasodilating beta-blockers. It is apparent that greater use of this drug class for blood pressure control would further enhance reduction of risk of heart failure, the most common cause of death in the first year of starting dialysis.

Comparing Beta-Blocking Effects of Bisoprolol, Carvedilol and Nebivolol

OBJECTIVE

Bisoprolol, carvedilol and nebivolol have been shown to be effective in the treatment of heart failure. However, the beta-blocking effects of these drugs have never been compared directly.

METHODS

Therefore, we performed a randomized, double-blind, placebo-controlled, cross-over trial in 16 healthy males. Subjects received 10 mg bisoprolol, 50 mg carvedilol, 10 mg nebivolol and placebo on the first morning followed by 5 mg bisoprolol once daily, 25 mg carvedilol twice daily, 5 mg nebivolol once daily and placebo for 1 week. Heart rate and blood pressure were measured at rest and exercise 3 and 24 h following intake of the first dose, and immediately before and 3 hours following intake of the last dose of each drug. In addition, effects of the drugs on nocturnal melatonin release were determined, and quality of life (QOL) was evaluated.

RESULTS

Heart rate at exercise was decreased at 3 h following intake of the first single dose of each drug by bisoprolol (-24%), carvedilol (-17%) and nebivolol (-15%), and at 24 h following intake of the respective last dose of each drug following 1 week of chronic administration by bisoprolol (-14%), carvedilol (12 h; -15%) and nebivolol (-13%) (p < 0.05 in all cases). Thus, trough-to-peak-ratios at long-term were as follows: Bisoprolol, 58%; carvedilol (12 h), 85%; nebivolol, 91%. Nocturnal melatonin release was decreased by bisoprolol (-44%, p < 0.05) whereas nebivolol and carvedilol had no effect. QOL with carvedilol was slightly but significantly lower than with the other drugs, whereas bisoprolol and nebivolol did not alter QOL.

CONCLUSIONS

These data show that peak beta-blocking effects of bisoprolol appear stronger than those of nebivolol and carvedilol. On the other hand, nebivolol exerts the highest trough-to-peak-ratio. However, beta-blocking effects of all the three drugs are similar at trough. Only bisoprolol but neither nebivolol nor carvedilol decreased nocturnal melatonin release, a feature which might cause sleep disturbances. Finally, only carvedilol slightly decreased QOL, whereas nebivolol and bisoprolol did not affect QOL. We conclude that different beta-blockers may exert clinically relevant different effects.

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.

Management of Global Risk Across the Continuum of Hypertensive Heart Disease

Identification and management of cardiovascular (CV) risk factors are essential to help prevent CV disease and slow its progression. Long-term epidemiologic data show that hypertension is associated with a two- to four-fold increase in CV morbidity and mortality; moreover, antihypertensive therapy has been proven to significantly reduce the risk of CV events. Clinical trial data also suggest that different antihypertensive agents generally provide similar reductions in CV risks and outcomes. Beta blockers have historically played an integral role in hypertension treatment, particularly among patients at high CV risk; however, a recent meta-analysis, based primarily on the use of atenolol, found that beta blockers may provide less clinical benefit as initial therapy than other classes of antihypertensive agents. Beta blockers are heterogeneous, and atenolol data may not be representative of other beta blockers. Newer beta blockers, which provide both cardioselective beta1-adrenergic receptor blockade and endothelium-dependent vasodilation, may prove to be more effective in reducing CV morbidity and mortality. Intensive strategies to control global CV risk have been shown to significantly reduce CV events. The challenge remains to develop effective risk assessment tools to identify at-risk patients who often go undetected.

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.

Synthesis and anti-bacterial activity of some novel 2-(6-fluorochroman-2-yl)-1-alkyl/acyl/aroyl-1H-benzimidazoles

Synthesis of some novel 2-(6-fluorochroman-2-yl)-1-alkyl/acyl/aroyl-1H-benzimidazoles by the condensation of o-phenylenediamine with 6-fluoro-3,4-dihydro-2H-chroman-2-carboxylic acid, and subsequent reactions with different types of electrophiles, have been reported. Some compounds exhibited promising anti-bacterial activity against Salmonella typhimurium; however, they showed poor activity against S. aureus. The biological activity against PDE IV for potential anti-asthamatic effect, and against DP-IV and PTP 1B for potential anti-diabetic effects was disappointing.