Molecular mechanisms of nerve block by local anesthetics

Abstract

Local anesthetics are drugs that block impulse conduction in nerves. They have been used clinically for almost a hundred years, but the exact mechanism of their action on nerves remains unknown. Several significant details about the molecular mechanisms of local anesthesia have appeared during the past five years. This information has come from neurophysiologic experiments on isolated, single nerve fibers, from physicochemical studies of nerve membranes during anesthesia, and from investigations of the effects of local anesthetics on artificial, lipid bilayer membranes. The object of this review is to critically summarize these results as they relate to current hypotheses of the molecular basis of anesthetic action. Before delving into the recent experimental evidence, the current concept of the ionic basis of nervous conduction is reviewed. 105 References are cited.