Acetaminophen is the most common cause of acute liver failure in the United States, largely from inadvertent overdose using multiple combination products. Adult ceiling: 4 g per 24 hours from all sources for short-term use; 2 to 3 g per 24 hours for chronic users, alcohol use, malnutrition, or liver disease. Pediatric: 75 mg/kg/day not to exceed adult ceiling. Acetaminophen is hidden in many OTC products: cold-flu combos (DayQuil, NyQuil, Theraflu), opioid-acetaminophen (Percocet, Norco, Vicodin), Tylenol PM (acetaminophen + diphenhydramine), and many migraine and menstrual products. Teaching: (1) total daily acetaminophen from all sources, (2) read every OTC and Rx label for the word acetaminophen or APAP or paracetamol, (3) do not double-dose, (4) avoid alcohol, (5) report jaundice, dark urine, RUQ pain, persistent nausea or vomiting, (6) hepatotoxicity is biphasic — N/V/malaise within 24 hours, then asymptomatic, then RUQ tenderness and rising AST/ALT 24 to 72 hours, then encephalopathy and coagulopathy by 72 to 96 hours.
For study reference only. Always follow current clinical guidelines and your institution’s protocols.