Nonspecific Action of β-Adrenergic Receptor Blocking Agents

Most β-adrenergic receptor blocking agents are known to possess nonspecific actions such as local anesthetic, quinidine-like or negative inotropic acitons in addition to specific β-receptor blocking action. All these nonspecific actions but negative intropism result from suppression of exciatory Na inward current in nerves and hearts. Several β-blockers, furthemore, exert intrinsic sympathomimetic activity both on intropy and chronotropy in the hearts. The present review focuses on potencies of β-blockers for β-receptor blocking, various nonspecific and intrinsic sympathomimetic actions…