Which anesthetic is metabolized in the liver and lungs?

Which anesthetic is metabolized in the liver and lungs?

• A. Bupivicaine
• B. Prilocaine
• C. Articaine
• D. Tetracaine

Answer: (B)

Prilocaine is processed by both the liver and the lungs, which sets it apart from many other local anesthetics. In the lungs, tissue enzymes metabolize prilocaine to o-toluidine, and in the liver it undergoes further metabolism. This dual route helps explain why prilocaine has a higher risk of methemoglobinemia due to the o-toluidine metabolite, especially at higher doses or with prolonged use. The other agents are mainly cleared by hepatic metabolism or, in one case, rapid inactivation by plasma esterases, not by significant pulmonary metabolism.

Prilocaine is processed by both the liver and the lungs, which sets it apart from many other local anesthetics. In the lungs, tissue enzymes metabolize prilocaine to o-toluidine, and in the liver it undergoes further metabolism. This dual route helps explain why prilocaine has a higher risk of methemoglobinemia due to the o-toluidine metabolite, especially at higher doses or with prolonged use. The other agents are mainly cleared by hepatic metabolism or, in one case, rapid inactivation by plasma esterases, not by significant pulmonary metabolism.