Library
Emergency
·
easy
Acetaminophen Intoxication
Flowchart
Play
Charcoal early; NAC if level above the Rumack–Matthew line.
Decision
Outcome
Decision
Acetaminophen ingestion. First triage question?
✓
Was it a single dose ≥7.5 g (or ≥150 mg/kg in peds)?
✗
Order liver transplant evaluation
✗
Give flumazenil
Decision
Single toxic dose confirmed. Is it ≤4 hours since ingestion AND acute?
✓
Yes → activated charcoal
✓
No / chronic / indeterminate → skip charcoal, draw labs
✗
Discharge — APAP is safe
Decision
After charcoal — next step?
✓
Acetaminophen level + AST/ALT + INR + Cr
✗
Wait 24 hours then recheck
Decision
Treatment indication?
✓
Level above Rumack–Matthew line, OR any AST/ALT elevation, OR >10 µg/mL with unclear timing → start NAC
✓
All below line, normal LFTs → discharge with follow-up
Outcome
N-acetylcysteine + monitor LFTs/INR
NAC replenishes glutathione and detoxifies NAPQI. Best efficacy <8 h but still indicated later. 21-h IV protocol most common.
Outcome
No NAC needed
Provide return precautions; reassess if late symptoms appear.