β-blockers in the management of hypertension: Focus on nebivolol

Hypertension is a major cardiovascular risk factor but most patients remain asymptomatic for many years. Successful therapy not only needs to be effective, it also needs to be well tolerated. β-blockers are well established as effective antihypertensive agents. However, one major drawback to the currently available β-blockers, particularly the noncardioselective β-blockers, is their side-effect profile, including sexual dysfunction, fatigue, depression and metabolic abnormalities such as impaired glucose tolerance and lipid abnormalities. Nebivolol (Bystolic®), a novel, highly cardioselective, th ird-gene ration β-blocker that recently received approval by the US FDA for the treatment of hypertension in the USA, is effective in treating blood pressure and has a favorable side-effect profile. Studies conducted in Europe, where nebivolol has been available for some time for the treatment of hypertension, have shown that nebivolol achieves blood pressure reductions comparable to other β-blockers but with fewer side effects. Additionally, nebivolol has demonstrated similar efficacy in blood pressure reduction when compared with calcium channel blockers and inhibitors of the renin-angiotensin system. When combined with hydrochlorothiazicle there was an additive antihypertensive effect. Lastly, nebivolol exhibits a vasoclilatory property that is related to its effect on nitric oxide, an intrinsic vasodilator produced in the vascular endothelium. Nebivolol enhances nitric oxide bioavailablility. Studies have also demonstrated nebivolol's ability to function as an antioxidant and decrease markers of oxidative stress. These effects are believed to ultimately produce a modulation of the endothelial dysfunction typically seen in hypertension.