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Acetaminophen overdose — RCPSC EM MCQ

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ModerateToxicologyAcetaminophen overdoseRCPSC EM

CTAS 2. A 19-year-old presents 10 hours after taking 20 g acetaminophen. She feels nauseated. AST is 64 U/L, INR 1.2, acetaminophen level is above the treatment line, and pregnancy test is negative. What is the most appropriate next step?

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Correct answer: B — Start N-acetylcysteine

Acetaminophen level above the nomogram treatment line, especially at 10 hours, requires N-acetylcysteine rather than delayed observation.

Reference: Ontario Poison Centre acetaminophen guidance; American College of Medical Toxicology