which medicines are beta blockers
Medical Definition of Beta adrenergic blocking agents. Beta adrenergic blocking agents: A class of drugs, also called beta blockers, that block beta-adrenergic substances such as adrenaline (epinephrine), a key agent in the sympathetic portion of the autonomic (involuntary) nervous system. By blocking the action of the sympathetic nervous system on the heart, these agents relieve stress on the heart.