A 66-year-old woman with a history of chronic alcohol abuse has had headaches and nausea for the past 4 days. She has become increasingly obtunded. On physical examination, she has right upper quadrant tenderness, tachycardia, tachypnea, and hypotension. Laboratory studies show serum AST of 475 U/L, ALT of 509 U/L, alkaline phosphatase of 23 U/L, total bilirubin of 0.9 mg/dL, albumin of 3.8 g/dL, and total protein of 6.1 g/dL. She is treated with N-acetylcysteine. Which of the following drugs has she most likely ingested in excess?

In the setting of chronic liver disease, the ingestion of acetaminophen is more likely to produce hepatotoxicity because detoxification by conjugation is exceeded. This leads to metabolism by cytochrome P-450 to the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which accumulates beyond the capacity of glutathione. The N-acetylcysteine increases available glutathione. Aspirin ingestion is a cause for Reye syndrome in children. Ibuprofen, which is a nonsteroidal anti-inflammatory drug (NSAID), meperidine, and oxycodone do not have significant hepatotoxicity.