Nebivolol: A Novel Beta-Blocker with Nitric Oxide-Induced Vasodilatation

Nebivolol is a novel beta(1)-blocker with a greater degree of selectivity for beta(1)-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.