A 64-year-old woman with osteoarthritis is brought to the emergency room because of a 2-day history of nausea and vomiting. Over the past few weeks, she has been taking acetaminophen frequently for worsening knee pain. Examination shows scleral icterus and tender hepatomegaly. She appears confused. Serum alanine aminotransferase (ALT) level is 845 U/L, aspartate aminotransferase (AST) is 798 U/L, and alkaline phosphatase is 152 U/L. Which of the following is the most likely underlying mechanism of this patient's liver failure?

Question

Quizplus · Accepted Answer

Eductional Objective: N-acetyl-p-benzoquinoneimine (NAPQI) is a toxic breakdown product of acetaminophen. At therapeutic doses, glutathione acts to inhibit toxic NAPQI. However, in cases of acetaminophen overdose, glutathione reserves are depleted and concentrations of NAPQI build up, ultimately leading to acute liver failure, as seen in this patient.

A 64-Year-Old Woman with Osteoarthritis Is Brought to the Emergency