NAPQI Wikipedia Acetaminophen toxicity Most patients who overdose on acetaminophen will initially be asymptomatic, as clinical symptoms of end organ toxicity do not manifest until 24 48 hours after an acute ingestion. Therefore, to identify a Acetaminophen Pathway (toxic doses), Pharmacokinetics Full article: Paracetamol (acetaminophen) overdose and hepatotoxicity: mechanism, treatment, prevention measures, and estimates of burden of disease