APAP (˜90%) + glucuronide OR sulfate through conjugation → nontoxic metabolites

APAP (˜5%) → toxic NAPQI (N-acetyl-p-benzoquinoneimine), through cytochrome P450… then, rather rapidly… toxic NAPQI + GSH (glutathione) → nontoxic metabolites

Toxic dose = 150 mg per kg or 15 g in a 100-kg adult.

Chronic ingestion of ” class=LK href=”javascript:void(0)” target=right xpath=”/CT{06b9ee1beed59419a81e5e1e1a4f60b0cc8cd1057525de73425b2b43f4df7f1b3a3cc636ba8697199dace83d364e9438}/ID(AB1-M10)”>>4 g per day may also be toxic.

First phase (initial 24 hours)—nonspecific findings (gastrointestinal [GI] symptoms, anorexia, pallor, lethargy); Liver function tests (LFTs) start to increase

Second phase (24-72 hours)—clinical (right upper quadrant [RUQ] pain) and laboratory (↑ prothrombin time [PT], ↑ bilirubin, ↑ creatinine) signs of hepatotoxicity

Third phase (72-96 hours)—fulminant hepatic failure (alanine aminotransferase [ALT] and aspartate aminotransferase [AST] ” class=LK href=”javascript:void(0)” target=right xpath=”/CT{06b9ee1beed59419a81e5e1e1a4f60b0cc8cd1057525de73425b2b43f4df7f1b3a3cc636ba8697199dace83d364e9438}/ID(AB1-M10)”>>10 K, ↑ PT, ↑ bilirubin producing jaundice)