Which is the only amide local anesthetic that contains an ester component?

Which is the only amide local anesthetic that contains an ester component?

• A. Articaine
• B. Lidocaine
• C. Mepivacine
• D. Prilocaine

Answer: (A)

The main idea is how the chemical structure of a local anesthetic determines its metabolism. Articaine is unique because it is an amide anesthetic that also contains an ester linkage in its molecular chain. That ester component allows the drug to be hydrolyzed by plasma esterases in addition to the usual hepatic metabolism of amides. So, although it’s classified as an amide, it behaves like an amide with an ester component. The other drugs listed are traditional amides without any ester bond, so they don’t have this ester-containing feature and rely predominantly on hepatic metabolism. This structural difference explains why articaine is the correct choice.

The main idea is how the chemical structure of a local anesthetic determines its metabolism. Articaine is unique because it is an amide anesthetic that also contains an ester linkage in its molecular chain. That ester component allows the drug to be hydrolyzed by plasma esterases in addition to the usual hepatic metabolism of amides. So, although it’s classified as an amide, it behaves like an amide with an ester component.

The other drugs listed are traditional amides without any ester bond, so they don’t have this ester-containing feature and rely predominantly on hepatic metabolism. This structural difference explains why articaine is the correct choice.