Lidocaine and bupivacaine are prototypes for which type of local anesthetics?

• A. Ester anesthetics
• B. Local vasoconstrictors
• C. General anesthetics
• D. Amide anesthetics

Answer: (D)

Lidocaine and bupivacaine are amide-type local anesthetics. Local anesthetics are classified by the chemical linkage in their structure into amides and esters. The presence of an amide bond between the aromatic ring and the amide group defines them as amides, and this linkage also drives their primary metabolism in the liver by hepatic amidases. This contrasts with ester-type anesthetics, which have an ester bond and are mainly hydrolyzed by plasma esterases and often have different durations of action and allergy considerations. Knowing they are amides helps explain their typical use pattern and pharmacokinetics, including generally longer duration of action and the need to consider liver function when planning dosing. Examples of other amide anesthetics include mepivacaine, prilocaine, and ropivacaine.