Which local anesthetic agent is metabolized primarily in the liver?

Lidocaine is metabolized primarily in the liver due to its chemical structure and the metabolic pathways it undergoes. It belongs to the amide group of local anesthetics, which are characterized by their metabolism primarily occurring in the liver through cytochrome P450 enzymes. This metabolic process involves N-dealkylation and hydroxylation, leading to active and inactive metabolites which are eventually excreted by the kidneys.

Understanding the liver's role in metabolizing lidocaine helps clarify its pharmacokinetics, especially in patients with liver dysfunction, where the metabolism might be decreased, potentially prolonging the anesthetic effect and increasing the risk of toxicity. This contrasts with other local anesthetics like procaine, which is primarily metabolized by plasma cholinesterases, and bupivacaine and articaine, which although they have some liver metabolism, have significant extra-hepatic clearance pathways as well.

Recognizing these metabolic pathways is essential for dental practitioners when considering the safety and efficacy of local anesthetic agents in different patient populations.