skip to main content

Acute acetaminophen overdose requiring NAC — RCPSC EM MCQ

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

ModerateToxicologyAcute acetaminophen overdose requiring NACRCPSC EM

CTAS 3: A 19-year-old presents 6 hours after taking 22 g acetaminophen. Vitals are normal and exam is benign. Acetaminophen concentration plots above the treatment line on the Rumack-Matthew nomogram. ALT and INR are normal. What is the most appropriate next step?

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

Reveal the answer and explanation

Correct answer: C — Start N-acetylcysteine now

A timed acetaminophen level above the nomogram treatment line requires NAC even before liver tests become abnormal.

Reference: Canadian Poison Centre resources; acetaminophen nomogram guidance