Beta-1/beta-2 adrenergic receptor (genotype-guided)

Class

Genotype-guided non-selective beta-blocker

Beta-1 and beta-2 adrenergic receptors are G protein-coupled receptors that mediate the effects of the sympathetic nervous system's catecholamines, epinephrine and norepinephrine. Beta-1 receptors predominate in cardiac tissue, where their activation increases heart rate and contractility; beta-2 receptors are more widespread in bronchial and vascular smooth muscle, where activation causes relaxation and dilation. In chronic heart failure, sustained sympathetic activation is compensatory in the short term but becomes cardiotoxic over time, contributing to myocardial remodeling and receptor desensitization. Non-selective beta-blockade, which antagonizes both beta-1 and beta-2 receptors, aims to interrupt this cycle, reduce myocardial oxygen demand, and allow partial recovery of receptor signaling capacity. Because individuals carry natural variation in the genes encoding these receptors, most notably common polymorphisms in the beta-1 receptor gene that alter how tightly the receptor couples to its downstream signaling machinery, the magnitude of clinical benefit from beta-blockade can differ substantially between genotypes. A genotype-guided approach uses this variation to identify patients more or less likely to derive benefit from a given agent. This class of mechanism is relevant broadly across cardiovascular disease, particularly heart failure and hypertension, where excess sympathetic drive contributes to disease progression.