Local Anesthetics

Abstract

The fascinating history of local anesthetics (LAs) began in South America with the herbal and traditional use of cocaine leaves by the indigenous peoples of Peru and Bolivia, the sacred plant of the Incas Erythroxylum coca. The use for anesthetic purposes dates back to 1884. Since then, the evolution of LAs has been closely related to research motivated by its efficacy and safety versus toxicity. According to their chemical structure, these drugs are classified into two main groups: esters and amino amides; however, there are three LAs with different characteristics: articaine, sameridine, and centbucridine. The pharmacological and toxic mode of action is primarily in the voltage-dependent sodium channels located in the cell membrane, which clinically produces analgesia, anesthesia, seizures, arrhythmias, and cardiac arrest. The quality of anesthesia and analgesia depends on the type of LA, dose, and application technique, while the deleterious effects are secondary to its plasma concentration. Nonanesthetic properties of LAs such as their antimicrobial, antineoplastic, antiarrhythmics, antitussive, and antiasthmatics effects have been described and are briefly reviewed.