What is an example of an ester local anesthetic?

Procaine is a classic example of an ester local anesthetic. Esters are characterized by their chemical structure, which includes a carbonyl group (C=O) adjacent to an ether link (–O–). Procaine contains the ester linkage in its structure, making it part of this class of local anesthetics.

Esters typically undergo hydrolysis in the body by plasma cholinesterase enzymes, leading to a relatively short duration of action compared to amide local anesthetics, which are metabolized by the liver. This property can influence the choice of anesthetic in various surgical and procedural contexts.

In contrast, the other options given—Carbocaine (an amide), Lidocaine (an amide), and Bupivacaine (also an amide)—do not belong to the ester class. Amide local anesthetics have different metabolic pathways and tend to provide longer-lasting effects due to their liver metabolism, distinguishing them significantly from ester anesthetics like Procaine.