Also Known As: Nebilet, Bystolic, Nebivolol
Nebivolol is a β1 receptor blocker with nitric oxide-potentiating vasodilatory effect used in treatment of hypertension and, in Europe, also for left ventricular failure. It is highly cardioselective under certain circumstances.
Beta blockers help patients with cardiovascular disease by blocking β1 and β2 receptors. Most of the benefits to the heart itself come from blocking β1 receptors, which are located mainly in the heart. Blocking of β2 receptors, which are in the vasculature and other tissues, causes most of the side effects of these medications. For this reason, beta blockers that selectively block β1 receptors (termed cardioselective or β1-selective beta blockers) produce fewer adverse effects (for instance, bronchoconstriction) than those drugs that non-selectively block both β1 and β2 receptors. Nebilovol has been marketed by Micro Labs under the brand name Nebilong; by Forest Laboratories under the name Bystolic; and by Menarini under the names Hypoloc, Lobivon, Nebilet, Nebilox, Nobiten, and Temerit. Micro Labs further ventured into providing a combination with diuretic (hydrochlorothiazide) marketed under the trade name Nebilong-H. In a laboratory experiment conducted on biopsied heart tissue, nebivolol proved to be the most β1-selective of the β-blockers tested, being approximately 3.5 times more β1-selective than bisoprolol. However, the drug's receptor selectivity in humans is more complex and depends on the drug dose and the genetic profile of the patient taking the medication. The drug is highly cardioselective at 5 mg. However, at doses above 10 mg, nebivolol loses its cardioselectivity and blocks both β1 and β2 receptors. (While the recommended starting dose of nebivolol is 5 mg, sufficient control of blood pressure may require doses up to 40 mg). Furthermore, nebivolol is also not cardioselective when taken by patients with a genetic makeup that makes them "poor metabolizers" of nebivolol (and other drugs). As many as 1 in 10 Whites and even more Blacks are poor CYP2D6 metabolizers and therefore might benefit less from nebivolol's cardioselectivity although currently there are no directly comparable studies.
Nebivolol is unique as a beta-blocker. Unlike carvedilol, it has a nitric oxide (NO)-potentiating, vasodilatory effect. Along with labetalol, celiprolol and carvedilol, it is one of four beta blockers to cause dilation of blood vessels in addition to effects on the heart. However, recent studies question the clinical relevance of this property to Nebivolol's efficacy.
Nebivolol lowers blood pressure (BP) by reducing peripheral vascular resistance, and significantly increases stroke volume with preservation of cardiac output. The net hemodynamic effect of nebivolol is the result of a balance between the depressant effects of beta-blockade and an action that maintains cardiac output. Antihypertensive responses were significantly higher with nebivolol than with placebo in trials enrolling patient groups considered representative of the U.S. hypertensive population, in Black patients, and in those receiving concurrent treatment with other antihypertensive drugs.