Which local anesthetic is an ester with rapid hydrolysis by esterases?

Which local anesthetic is an ester with rapid hydrolysis by esterases?

• A. Chloroprocaine
• B. Bupivacaine
• C. Etidocaine
• D. Prilocaine

Answer: (A)

Local anesthetics fall into two families by their chemical linkage: esters and amides. Esters are rapidly broken down by plasma esterases in the blood and tissues, which shortens their duration of action dramatically and allows for quick recovery after a block. Chloroprocaine is an ester, so it is rapidly hydrolyzed by esterases, giving an ultrashort duration with quick onset and offset. This makes it particularly useful when only a brief anesthetic effect is needed. The other agents listed are amides, which are metabolized mainly in the liver and have a longer duration of action because they are not cleaved as quickly by esterases.

Local anesthetics fall into two families by their chemical linkage: esters and amides. Esters are rapidly broken down by plasma esterases in the blood and tissues, which shortens their duration of action dramatically and allows for quick recovery after a block.

Chloroprocaine is an ester, so it is rapidly hydrolyzed by esterases, giving an ultrashort duration with quick onset and offset. This makes it particularly useful when only a brief anesthetic effect is needed. The other agents listed are amides, which are metabolized mainly in the liver and have a longer duration of action because they are not cleaved as quickly by esterases.