Acetaminophen overdose — MCCQE Part 1 MCQ

Correct answer: A — Check level at appropriate time and start N-acetylcysteine if above treatment line or high-risk/uncertain

Check level at appropriate time and start N-acetylcysteine if above treatment line or high-risk/uncertain is best because early labs can be normal and NAC prevents hepatic injury. Wait for confirmatory testing before any stabilisation is suboptimal because resuscitation and time-critical treatment should not wait when instability is present; Discharge once symptoms temporarily improve is suboptimal because temporary improvement can precede deterioration; Give an adjunctive medication as the sole first-line treatment is suboptimal because adjuncts do not replace definitive stabilisation; Delay escalation until cardiac arrest or respiratory failure occurs is suboptimal because early escalation is central to emergency care. Do not wait for transaminases to rise.

Reference: Canadian poison centre guidance