Bystolic Drug Classification
Bystolic (nebivolol) is a cardioselective (β1-selective) beta-blocker with vasodilatory properties mediated through nitric oxide release. 1, 2, 3, 4
Specific Classification Details
Nebivolol belongs to the "Beta blockers—cardioselective and vasodilatory" subclass of beta-adrenergic antagonists 1, 2, 5, 3, 6. This distinguishes it from traditional beta-blockers in several important ways:
Key Pharmacologic Characteristics
β1-selectivity: At therapeutic doses (≤10 mg), nebivolol preferentially blocks β1-adrenergic receptors over β2-receptors in extensive metabolizers (most of the population). At higher doses or in poor metabolizers, this selectivity is lost 4
Vasodilatory mechanism: Unlike traditional beta-blockers, nebivolol induces vasodilation through nitric oxide-mediated pathways, specifically through endothelium-dependent nitric oxide stimulation 7, 3, 6
No intrinsic sympathomimetic activity: Nebivolol lacks intrinsic sympathomimetic activity and membrane-stabilizing effects at therapeutic concentrations 4
No α1-blockade: At clinically relevant doses, nebivolol does not demonstrate α1-adrenergic receptor blocking activity, differentiating it from combined alpha-beta blockers like carvedilol or labetalol 4
Clinical Context
Nebivolol is classified as a third-generation beta-blocker 7, distinguishing it from:
- First-generation (nonselective): propranolol, nadolol
- Second-generation (cardioselective): metoprolol, atenolol, bisoprolol
- Third-generation (vasodilatory): nebivolol, carvedilol (though carvedilol achieves vasodilation through α1-blockade rather than nitric oxide)
The vasodilatory properties confer unique hemodynamic effects including reduced peripheral vascular resistance while maintaining cardiac output, improved endothelial function, and potentially better tolerability compared to traditional beta-blockers 8, 9.
Guideline Recognition
Major hypertension guidelines 1, 2, 3, 6, 10 consistently classify nebivolol separately from other cardioselective beta-blockers, specifically noting its nitric oxide-induced vasodilation mechanism. The 2017 ACC/AHA guidelines explicitly state: "Nebivolol induces nitric oxide–induced vasodilation. Avoid abrupt cessation." 1, 2, 3, 6