Effects of the systemic beta-adrenoceptor antagonist nebivolol on ocular hemodynamics in glaucoma patients

BACKGROUND

Systemic antihypertensive treatment in glaucoma patients with hypertension carries the potential risk of an additional deterioration in ocular hemodynamics due to the reduction in ocular perfusion pressure. Nebivolol is a beta1-selective adrenoceptor antagonist with known peripheral vasodilatory effects due to NO-releasing properties. The effect of a switch in systemic beta-blocker treatment to nebivolol on retrobulbar hemodynamics in glaucoma patients with arterial hypertension was therefore investigated.

MATERIAL/METHODS

Peak systolic (PSV) and end-diastolic (EDV) velocity in the short and long posterior ciliary arteries (SPCA, LPCA), central retinal artery (CRA), and ophthalmic artery (OA) were recorded by color Doppler imaging (CDI) in 23 glaucoma patients with arterial hypertension using their primary systemic beta-blocker medication and four weeks after a switch to nebivolol.

RESULTS

Compared with the first recording under the primary antihypertensive medication, the CDI measurements after four weeks of nebivolol treatment revealed a significant acceleration of the PSV in the SPCA and LPCA and the EDV in the SPCA and CRA. No significant differences in flow velocities were found for the OA. Intraocular pressure and systemic blood pressure remained unchanged.

CONCLUSIONS

Switching blood pressure treatment to nebivolol in glaucoma patients with hypertension leads to accelerated blood flow in the small retrobulbar vessels. A stabilization of ocular perfusion might be of particular importance in this group of co-morbid patients.

Development and validation of a stability-indicating column high-performance liquid chromatographic assay method for determination of nebivolol in tablet formulation

A simple, precise, and accurate isocratic reversed-phase (RP) stability-indicating column high-performance liquid chromatographic (HPLC) assay method was developed and validated for determination of nebivolol in solid pharmaceutical dosage forms. Isocratic RP-HPLC separation was achieved on a Phenomenex Luna C8 (2) column (250 mm x 4.6 mm id, 5 microm particle size) using mobile phase composed of acetonitrile-pH 3.5 phosphate buffer (35 + 65, v/v) at a flow rate of 1.0 mL/min, and detection was performed at 280 nm using a photodiode array detector. The drug was subjected to oxidation, hydrolysis, photolysis, and heat to apply stress conditions. The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The method was linear in the drug concentration range of 40-160 microg/mL with a correlation coefficient of 0.9999. The repeatability relative standard deviation (RSD) for 6 samples was 0.69%, and the intermediate precision (RSD) for 6 samples was 1.39%. The accuracy (recovery) was between 98.57 and 99.55%. Degradation products produced as a result of stress studies did not interfere with detection of nebivolol, and the assay can thus be considered stability-indicating.

The vasodilatory beta-blockers

Although well established in treating hypertension and cardiovascular (CV) disease, clinical trial data suggest that beta-blockers (eg, atenolol) may be less effective than other antihypertensive classes in reducing stroke and CV mortality despite similar blood pressure (BP) reductions. One possible explanation is that atenolol is less effective in reducing central aortic pressure. Newer vasodilating beta-blockers may prove more effective in reducing central pressure and cardiovascular events. Carvedilol and labetalol appear to cause vasodilation through alpha(1)-receptor blockade; nebivolol induces endothelium-dependent vasodilation by stimulating nitric oxide bioactivity. Their favorable hemodynamic profile includes reduction of peripheral vascular resistance (PVR) while maintaining or improving cardiac output (CO), stroke volume, and left ventricular function, whereas nonvasodilating beta-blockers tend to raise PVR and reduce CO and left ventricular function. Compared with conventional beta-blockers, vasodilating beta-blockers have beneficial hemodynamic effects including decreased pressure wave reflection from the periphery, leading to decreases in central aortic blood pressure. Larger trials are needed to determine whether reduced central pressure will translate into improved CV outcomes compared with nonvasodilating beta-blockers.

Determination of nebivolol and valsartan in a fixed-dose combination by liquid chromatography

An accurate and reproducible liquid chromatographic assay method was developed and validated for the determination of nebivolol and valsartan in a capsule formulation. Buffer-acetonitrile (55 + 45, v/v) was used for reversed-phase liquid chromatography to determine the contents of nebivolol and valsartan in the combination-capsule dosage form. The method was validated by determining parameters such as specificity, linearity, limits of detection and quantitation, precision, accuracy, and robustness. The method was found to be specific against placebo interference. Linearity was evaluated over the concentration ranges of 2-8 micro/mL for nebivolol and 32-128 microg/mL for valsartan (the correlation coefficient was 0.9999 for both nebivolol and valsartan). Both the intraday and interday precision values of the system and the method were determined. The accuracy of the method ranged from 100.66 to 102.58% for nebivolol and from 101.17 to 101.85% for valsartan. The proposed method was found to be robust when slight but deliberate changes were made in the analytical conditions. The developed method was found suitable for the assay determination of nebivolol and valsartan in a capsule formulation.

Major differences in gene expression in human coronary smooth muscle cells after nebivolol or metoprolol treatment

OBJECTIVE

Vascular smooth muscle cells play a pivotal role in all stages of atherogenesis. Targeting their inflammatory and proliferative qualities might therefore inhibit the progression of atherosclerosis. This study aimed to characterize and compare the effects of the beta-receptor antagonists nebivolol and metoprolol on gene expression in human coronary artery smooth muscle cells (hcaSMC).

METHODS AND RESULTS

hcaSMC were incubated with nebivolol or metoprolol (10(-5) mol/l) for 72 h. The downregulated genes are involved in inflammatory processes, oxidative stress and smooth muscle cell proliferation: i.e. downregulated were by nebivolol: interleukin-1alpha, cyclooxygenase-2, tumor-necrosis-factor (TNF)-alpha-induced protein 6, PDGF-A, growth-related oncogenes 2 and 3. Metoprolol increased the expression of interleukin-1alpha, cyclooxygenase-1, TNF-alpha-induced protein 3, heme oxygenase 1 and granulocyte/macrophage-colony-stimulating factor. In addition downregulated was monocyte chemoattractant protein 1 (MCP-1) mRNA by nebivolol. Nebivolol (10(-5) mol/l) reduced the amount of basal NF-kappaB after 48 and 52 h but not metoprolol. In the culture supernatants, MCP-1 concentrations were reduced by nebivolol.

CONCLUSIONS

Nebivolol induced changes in the expression of inflammatory mediators in hcaSMC. These results add to data that suggest specific anti-inflammatory qualities of a beta-blocker of the third generation in comparison to metoprolol.

[Endothelioprotective properties of L-arginine in a nitric oxide deficiency model]

In laboratory animals with endothelial dysfunction (nitric oxide deficiency) modeled by the introduction of NO-synthase inhibitor L-NAME, the activation of endothelioprotective effects of enalapril, lozartan, amlodipine, indapamide and nebivolol is revealed for their introduction in combination with L-arginine. This result was confirmed by the behavior of a generalizing parameter, the coefficient of endothelial dysfunction (CED) calculated using the results of tests on endothelium-dependent and -independent vasodilation.

[Comparison of effects of nebivolol and atenolol on P-wave dispersion in patients with hypertension]

BACKGROUND

P-wave dispersion has been shown to be a noninvasive electrocardiographic predictor for development of atrial fibrillation . Thus it may be possible to attenuate atrial fibrillation risk through normalization of P-wave variables and improvement in P-wave dispersion may be an important goal in treatment of hypertension.

OBJECTIVE

To compare the effects of nebivolol, a new b-blocker that have additional vasodilating activity via acting on endothelium and nitric oxide release, and atenolol on P-wave duration and dispersion in patients with mild-to-moderate hypertension.

METHODS

A total of 34 newly-diagnosed hypertensive patients were enrolled in the study. The patients were randomly assigned to receive treatment with either nebivolol (5 mg) or atenolol (50 mg). P-wave durations (Pmin and Pmax) and P-wave dispersion were measured before and one month after treatment.

RESULTS

While Pmin increased (50,6 +/- 11,2 ms to 54,7 +/- 9,1 ms, p=0,05), Pmax decreased (111,9 +/- 9,1 ms to 104,0 +/- 12,4 ms, p=0,003) and P-wave dispersion decreased (62,5 +/- 10,6 ms to 51,3 +/- 8,9 ms, p < 0,001) with nebivolol, Pmin increased (44,4 +/- 9,8 ms to 58,0 +/- 15,5 ms, p=0,02), Pmax didn t change (106,1 +/- 13,8 ms to 107,0 +/- 11,6 ms, p=NS) and P-wave dispersion decreased (61,7 +/- 15,0 ms to 49,0 +/- 13,7 ms, p < 0.001) with atenolol. However, there was no statistical difference between pre- and post-treatment values of two groups.

CONCLUSIONS

Both nebivolol and atenolol are effective in improvement of P-wave dispersion in patients with hypertension and there s no significant difference between them.

Impact of nebivolol on levels of serum nitric oxide, plasma von Willebrand factor and exercise stress testing parameters in hypertensive and ischemic heart disease patients

BACKGROUND

The dysfunction of vascular endothelium precedes the development of atherosclerosis in patients with arterial hypertension. Nebivolol is a very specific beta-blocker, which can be characterized by a strong endothelial vasodilatative effect. The aim of the study was the assessment of changes in concentrations of serum nitric oxide (NO), plasma von Willebrand factor (vWf) and selected parameters of electrocardiographic exercise tests after 4-week nebivolol treatment.

METHODS

Twenty-one patients were included in the study, aged from 34 to 82 years with primary arterial hypertension or primary arterial hypertension and ischemic heart disease. Blood samples were taken for measurements of serum NO and plasma vWf. Electrocardiographic stress tests were also performed. Subsequently, nebivolol was administered for four weeks and the aforementioned measurements were repeated.

RESULTS

A significant increase in serum NO concentration was found in all the investigated patients after nebivolol treatment. A prolongation of exercise time, increase in metabolic equivalent and decrease in double product were also noted in patients after nebivolol treatment.

CONCLUSIONS

Nebivolol treatment improves parameters of electrocardiographic exercise test in patients with arterial hypertension. The improvement of the parameters of the exercise test was not observed in those patients who showed no significant increase in serum NO concentration following nebivolol treatment.

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.

[Heart rate variability dynamics during treatment of arterial hypertension]

Investigation of the dynamics of heart rate variability (HRV) in anti-hypertension therapy can facilitate the evaluation of the effectiveness of treatment.

AIM OF INVESTIGATION

to compare anti-hypertension effect of monotherapy with nebivolol and dilatrend with dynamics of HRV and the estimation of the state of patients with mild arterial hypertension (AH) and metabolic syndrome (MS).

MATERIAL AND METHODS

HRV was studied in 42 patients with mild AH and MS at the age of 32-60. Eighteen of them were treated with 5 mg of nebivolol during 24 weeks, and twenty-four with 25-50 mg of dilatrend during 16 weeks. All the patients were subjected to 24-hour ECG monitoring with analysis of HRV and arterial pressure (AP) before and after treatment. The main feature of HRV analysis was investigation of dependence of sinus arrhythmia on the mean value of heart rate (HR) RESULTS: With nebivolol treatment AP decreased in 11 patients, HRV became better in 9 patients. 7 cases manifested coincidence of AP reduction and HRV improvement. In 6 cases out of 7 when AP did not decrease, HRV did not change. Worsened HRV was observed in 3 cases: in one case with growing AP and in 2 cases with decreasing AP. All the patients, except one, regarded their state as improved. With dilatrend treatment AP lowered in 16 cases. In 9 cases HRV became better, in 11 cases it remained the same, and in 4 cases it became worse. Positive HRV dynamics in 7 cases out of 9 was accompanied by lowering of AP, while negative dynamics was observed in one case with rise of AP and in three cases with very low AP or in the absence of AP dynamics. 14 patients felt better, 6 of them manifested better level both of AP and HRV.

CONCLUSION

The method of 24-hour HRV analysis based on assessment of dependence of the value of sinus arrhythmia on HR is useful in evaluating the effectiveness of anti-hypertension therapy. As a rule, an effective decrease in AP is accompanied with improvement of HRV. The absence of improvement of deterioration of HRV in anti-hypertension therapy is a factor which should be taken into consideration when choosing the mode of therapy.

[Clinico-immunological disorders in patients with ischemic heart disease combined with metabolic syndrome and modulating effect of nebivolol for their correction]

AIM

To evaluate clinico-immunological disorders in patients with ischemic heart disease (IHD) and metabolic syndrome (MS), to study an immunocorrective action of nebivolol during 6-month treatment.

MATERIAL AND METHODS

A total of 54 patients with postinfarction left ventricular dysfunction and chronic cardiac failure of NYHA functional class II-III were divided into two groups: group 1 (n=24) comprised patients with effort angina FC II-III and impaired glucose tolerance, group 2 (n=30) consisted of anginal patients associated with type 2 diabetes mellitus (DM). Clinical, laboratory and functional indices were registered before therapy with nebivolol and 6 months after it. Immunological control included determination of the subpopulation composition of lymphocytes, immunoglobulins, circulating immune complexes (CIC), antibodies to cardiolipin (CL), proinflammatory cytokines: IL-1alpha, IL-2, IL-6, IL-8, alpha-interferon, tumor necrosis factor alpha (TNFalpha).

RESULTS

Nebivolol demonstrated good antihypertensive and anti-ischemic cardioprotective efficacy in IHD patients with MS, it did not deteriorate atherogenic dyslipidemia and impaired carbohydrate metabolism. As a good immunocorrector, nebivolol significantly inhibited cytokine overactivation, had a weak effect on dysimmunoglobulinemia, CIC level and expression to CL antibodies. Side effects were not recorded.

CONCLUSION

IHD patients with MS (especially patients with type 2 DM) have manifest immune disorders presenting with overactivation of proinflammatory cytokines with high levels of IgA, IgG, CIC and antibodies to CL in the presence of low immunoregulatory index. Nebivolol provided good control of arterial hypertension, myocardial ischemia, positive changes in immunological indices, improved intracardiac hemodynamics.

[Clinical efficacy of ivabradin and nebivolol addition in combined treatment of ischemic heart disease patients with left ventricular dysfunction]

AIM

To assess ivabradin and nebivolol efficacy in combined treatment of ischemic heart disease patients with chronic heart failure (CHF) of functional class (FC) II-III by NYHA, impact of these drugs on quality of life, circadian indices of myocardial ischemia (CMI), left ventricular (LV) contractility.

MATERIAL AND METHODS

A total of 92 patients with CHF of FC II-III (mean age 57.3 +/- 4.5 years) were randomized into 3 groups. Patients of group 1 (n = 30) received combined basic therapy: inhibitors of ACE, diuretics, aspirin, statins, on demand nitrates. Patients of group 2 (n = 33) received basic combined treatment plus nebivolol (nebilet, Berlin-Chemie/Menarini) in a dose 5.0 mg/day. Group 3 (n = 29) was given basic therapy plus ivabradin (coraxan) in a mean dose 7.5 mg.

RESULTS

The addition of ivabradin and nebivolol to combined treatment of ischemic heart disease with LV dysfunction brought about control over heart rate (HR), improved quality of life, reduced severity of CHF, CMI, number of episodes of painful and painless ischemia. In reduced by nebivolol HR addition of ibavradin improved systolic and diastolic LV function. The analysis of HR variability in ivabradin administration showed enhancement of parasympathic activity in the vegetative balance. Administration of nebivolol produced modulated attenuation of sympathic activity.

CONCLUSION

Addition of ivabradin and nebivolol to combined treatment of ischemic heart disease with LV dysfunction raises efficacy of treatment.

Long-term cost-effectiveness analysis of nebivolol compared with standard care in elderly patients with heart failure: an individual patient-based simulation model

BACKGROUND AND OBJECTIVE

The SENIORS trial demonstrated that nebivolol is effective in the treatment of heart failure in elderly patients (e.g. > or = 70 years). This analysis evaluates the cost effectiveness of nebivolol compared with standard treatment.

METHODS

An individual patient-simulation model based on a Markov modelling framework was developed to compare costs and outcomes for nebivolol and standard care in patients with heart failure starting treatment at the age of 70 years. Health states were defined by New York Heart Association (NYHA) class and death. At a given NYHA class and a given cycle, patients could die, be hospitalized for cardiovascular disease or remain stable. Risks for these events were derived from individual patient data from the SENIORS trial. The risk of each event in a given cycle was based on the subject's baseline characteristics and time in the current health state. The economic analysis was conducted from the UK NHS perspective with a lifetime horizon. The costs (euro; year 2006 values) considered were drug costs for nebivolol and other cardiac drugs, costs of GP visits, outpatient specialist visits and cardiovascular-related hospitalizations. Univariate and probabilistic sensitivity analysis was conducted.

RESULTS

In the baseline analysis, the total cost per patient was euro6740 and euro9288, and QALYs were 5.194 and 5.843 for patients aged 70 years at the start of treatment for the standard treatment and nebivolol groups, respectively. The probabilistic sensitivity analysis provided an incremental cost-effectiveness ratio of euro3926 (95% CI 3731, 4159) per QALY.

CONCLUSIONS

This analysis indicates that nebivolol appears to be a cost-effective treatment for elderly patients with heart failure compared with standard care.

Effect of nebivolol and metoprolol treatments on serum asymmetric dimethylarginine levels in hypertensive patients with type 2 diabetes mellitus

OBJECTIVE

Elevated asymmetric dimethylarginine (ADMA) levels, an endogenous inhibitor of nitric oxide synthase, are an important cardiovascular risk factor. In patients with diabetes, increased ADMA levels have been reported, which may be associated with endothelial dysfunction. In this study, effect of nebivolol on serum ADMA levels in hypertensive patients with type 2 diabetes have been compared with metoprolol, an another beta-blocker.

METHODS

A total of 54 patients (27 female, 27 male; mean age: 53.0+/-8.7 years) with type 2 diabetes and hypertension were included in this randomized, open-label, prospective study. Patients were randomized to receive either nebivolol 5 mg/day (n=28) or metoprolol 100 mg/day (n=26) for 12 weeks. When the patients could not reach target blood pressure levels at the end of week 4, indapamide (2.5 mg/day) was added. Enzyme Linked Immunosorbent Assay was used for serum ADMA measurements.

RESULTS

Similar reductions in blood pressure values were observed in both groups (p>0.05). In nebivolol group, there were no significant changes in serum ADMA levels compared to baseline (0.6+/-0.2 micromol/l vs 0.6+/-0.1 micromol/l, p>0.05), whereas in metoprolol group a 35.6% increase in serum ADMA levels was observed (0.6+/-0.1 micromol/l vs 0.7+/-0.2 micromol/l, p<0.01).

CONCLUSION

We observed a significant increase in ADMA levels, a marker of endothelial dysfunction, during metoprolol treatment, whereas nebivolol had neutral effects on ADMA levels in patients with type 2 diabetes mellitus and hypertension.

Does the beta-blocker nebivolol increase coronary flow reserve?

INTRODUCTION

Nebivolol, a highly selective beta1-adrenergic receptor-blocker, increases basal and stimulated endothelial nitric oxide (NO)-release. It is unknown, whether coronary perfusion is improved by the increase in NO availability. Therefore, we sought to evaluate the effect of nebivolol on coronary flow reserve (CFR) and collateral flow.

METHODS

Doppler-flow wire derived coronary flow velocity measurements were obtained in ten controls and eight patients with coronary artery disease (CAD) at rest and after intracoronary nebivolol. CFR was defined as maximal flow during adenosine-induced hyperemia divided by resting flow. In the CAD group, collateral flow was determined after dilatation of a flow-limiting coronary stenosis. Collateral flow index (CFI) was defined as the ratio of flow velocity during balloon inflation divided by resting flow.

RESULTS

CFR at rest was 3.0+/-0.6 in controls and 2.1+/-0.4 in CAD patients. After intracoronary doses of 0.1, 0.25, and 0.5 mg nebivolol, CFR increased to 3.4+/-0.7, 3.9+/-0.9, and 4.0+/-0.1 (p<0.01) in controls, and to 2.3+/-0.7, 2.6+/-0.9, and 2.6+/-0.5 (p<0.05) in CAD patients. CFI decreased significantly with intracoronary nebivolol and correlated to changes in heart rate (r=0.75, p<0.001) and rate-pressure product (r=0.59, p=0.001).

DISCUSSION

Intracoronary nebivolol is associated with a significant increase in CFR due to reduction in resting flow (controls), or due to an increase in maximal coronary flow (CAD patients). CFI decreased with nebivolol parallel to the reduction in myocardial oxygen consumption.

Nebivolol Induces Nitric Oxide Release in the Heart Through Inducible Nitric Oxide Synthase Activation

Nebivolol is a beta1-adrenergic receptor antagonist that also reduces blood pressure by evoking endothelial NO production and vasodilation. We aimed at assessing whether nebivolol induces NO production also in the heart and delineating the molecular mechanisms involved. Using the fluorescent probe diaminofluorescein, we found that nebivolol induces a dose-dependent NO production in the heart, statistically significant already at 10(-7) mol/L. It is not an effect because of the blockade of beta1-adrenergic receptor, because this effect is not shared by another drug of the same class, atenolol. Because nebivolol has been reported to act as an agonist on other beta-adrenergic receptors, we tested NO production in the presence of receptor antagonists. Nebivolol was not able to induce NO production in presence of the beta3-antagonist SR59230A, indicating a fundamental role for beta3-adrenergic receptors in cardiac NO production by nebivolol. Moreover, inducible NO synthase inhibition abolishes NO release in the heart, indicating that nebivolol induces NO production by acting on the inducible isoform of the enzyme. The action of nebivolol on inducible NO synthase was confirmed by real-time PCR experiments, showing cardiac overexpression of inducible NO synthase but not neuronal NO synthase or endothelial NO synthase, after 5 hours of treatment with nebivolol. In conclusion, our study demonstrates that nebivolol also stimulates NO production in the heart. This action of nebivolol is exerted via a signaling pathway starting from the activation of beta3-adrenergic receptors and leading to overexpression of inducible NO synthase. Cardiac NO production by nebivolol could participate in the cardiovascular effects of nebivolol treatment in patients affected by hypertension and heart failure.

Simultaneous determination of fixed dose combination of nebivolol and valsartan in human plasma by liquid chromatographic-tandem mass spectrometry and its application to pharmacokinetic study

A rapid, sensitive and accurate liquid chromatographic-tandem mass spectrometry method is described for the simultaneous determination of nebivolol and valsartan in human plasma. Nebivolol and valsartan were extracted from plasma using acetonitrile and separated on a C18 column. The mobile phase consisting of a mixture of acetonitrile and 0.05 mM formic acid (50:50 v/v, pH 3.5) was delivered at a flow rate of 0.25 ml/min. Atmospheric pressure ionization (API) source was operated in both positive and negative ion mode for nebivolol and valsartan, respectively. Selected reaction monitoring mode (SRM) using the transitions of m/z 406.1-->m/z 150.9; m/z 434.2-->m/z 179.0 and m/z 409.4-->m/z 228.1 were used to quantify nebivolol, valsartan and internal standard (IS), respectively. The linearity was obtained over the concentration range of 0.01-50.0 ng/ml and 1.0-2000.0 ng/ml and the lower limits of quantitation were 0.01 ng/ml and 1.0 ng/ml for nebivolol and valsartan, respectively. This method was successfully applied to the pharmacokinetic study of fixed dose combination (FDC) of nebivolol and valsartan formulation product after an oral administration to healthy human subjects.

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.

The effects of nebivolol on fibrinolytic parameters in mild and moderate hypertensive patients

BACKGROUND

The aim of the present study was to investigate the effects of nebivolol (5 mg daily) on plasma levels of hemostatic and fibrinolytic endothelial function markers in mild or moderate hypertensive patients.

METHODS AND RESULTS

Thirty-five (22 female, 13 male; mean +/- SD 54.7 +/- 11.3 years of age) mild and moderate hypertensive patients were included the study. The mean systolic blood pressure [BP] was 160 mmHg (range 150 mmHg to 165 mmHg) and the mean diastolic BP was 100 mmHg (range 90 mmHg to 100 mmHg). Plasma tissue plasminogen activator antigen (tPA-Ag), plasminogen activator inhibitor type 1 antigen (PAI-1-Ag), PAI-1 activity, tPA-Ag/PAI-1-Ag index, fibrinogen and euglobulin lysis time were determined before and after two months of therapy. tPA-Ag and PAI-Ag levels were measured by ELISA. After this period, treatment with nebivolol (5 mg/day) in all patients was associated with a significant decrease in systolic BP and diastolic BP (P<0.001 for each), heart rate (P<0.01), fibrinogen (P<0.005) and euglobulin lysis time (P<0.01). The tPA-Ag and tPA-Ag/PAI-1-Ag index levels were increased significantly (P<0.001 for each) in all patients, but the PAI-1-Ag (P>0.05) and PAI-1 activity (P>0.05) did not show significant change. In the present study, there was no correlation between decreases in arterial BP and decreases in fibrinolytic parameters (P>0.05), but there was a positive, statistically significant correlation between fibrinogen and body mass index (P<0.001).

CONCLUSIONS

The results indicated that, compared with no treatment, a two-month treatment trial with nebivolol was associated with a more favourable modification of hemostatic and fibrinolytic status in addition to antihypertensive effects.