Which local anesthetics are amide-type and metabolized in the liver?

• A. Procaine
• B. Lidocaine only
• C. Bupivacaine only
• D. Lidocaine and Bupivacaine

Answer: (D)

Amide-type local anesthetics are cleared primarily by the liver using enzymatic breakdown of the amide bond, rather than by plasma cholinesterases. This makes hepatic metabolism a key factor for their duration and toxicity risk. Among the common agents, lidocaine and bupivacaine are classic amide-type drugs and both are metabolized in the liver. Procaine, on the other hand, is an ester-type local anesthetic that is rapidly hydrolyzed in the blood by plasma cholinesterases, so its clearance relies less on hepatic metabolism. That combination—lidocaine and bupivacaine—fits both criteria: amide-type and liver-metabolized.