Which local anesthetic is metabolized by pseudocholinesterase?

Benzocaine is a local anesthetic that is metabolized by pseudocholinesterase. This enzyme is responsible for the hydrolysis of certain ester local anesthetics, and while benzocaine is primarily used topically, understanding its metabolism is important for its safe application.

The significance of pseudocholinesterase in the metabolism of benzocaine highlights how this anesthetic is processed in the body, which can impact the duration of action and potential toxicity, especially in individuals with atypical forms of pseudocholinesterase. This characteristic sets benzocaine apart from the other options, which do not rely on pseudocholinesterase for their metabolism.

Lidocaine, mepivacaine, and prilocaine are all amide local anesthetics, which are metabolized primarily in the liver via cytochrome P450 enzymes rather than by pseudocholinesterase. This difference in metabolic pathways can lead to varying clinical considerations such as half-life, duration of action, and risks for systemic toxicity, particularly in patients with liver disease. This understanding is crucial in clinical practice when selecting the appropriate local anesthetic for a given procedure.