skip to main content

Acetaminophen overdose — RCPSC EM MCQ

Instant feedback + full explanation. One question, done properly.

ModerateToxicologyAcetaminophen overdoseRCPSC EM

A 24-year-old woman presents 10 hours after taking an unknown number of acetaminophen tablets. She is nauseated, AST is 72 U/L, INR is 1.4, and serum acetaminophen level will not return for 3 hours. What is the most appropriate investigation?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Serum acetaminophen concentration with ALT/AST and INR

Serum acetaminophen concentration interpreted against timing, together with liver enzymes and INR, is central to risk assessment. Treatment should start if results are delayed or timing is uncertain.

Reference: Ontario Poison Centre guidance; Canadian toxicology practice