👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Pharmacological Therapies🔖 Free to read, print, and share
Also known as: Tylenol overdose · paracetamol toxicity · acetaminophen overdose
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Use this quick-reference guide to spot, treat, and prevent Acetaminophen Poisoning in Children on the NCLEX. Keep it handy during review and on exam day!
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📒 The 1-minute cheat sheet
📌 Phases
1: N/V, malaise (0-24 hr)
2: false improve, RUQ pain
3: hepatic failure (72-96 hr)
✅ Do
Plot level on Rumack nomogram
Activated charcoal if < 1 hr
Monitor LFTs, PT/INR
🧪 Meds
NAC (Mucomyst) PO or IV
Most effective within 8 hr
🚩 Report
Jaundice, ↑ liver enzymes
Coagulopathy, encephalopathy
📚 Acetaminophen Poisoning in Children — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Acetaminophen overdose is a leading cause of pediatric poisoning and the most common cause of acute liver failure from a drug. Toxicity damages the liver when the body's glutathione stores are depleted by a toxic metabolite. Key principle: the antidote N-acetylcysteine is most effective within 8-10 hours of ingestion, so timing and the Rumack-Matthew nomogram guide treatment.
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Key points
Understand these first
Toxicity is dose-related; a single acute ingestion of about 150 mg/kg or more is potentially toxic.
Clinical course has four stages: early stage may be asymptomatic or show only nausea, vomiting, and malaise.
Stage 2 (24-72 hours) brings right upper quadrant pain and rising liver enzymes despite the child feeling better.
Peak hepatotoxicity (stage 3) occurs at 72-96 hours with jaundice, coagulopathy, and possible liver failure.
N-acetylcysteine (NAC) is the antidote; it replenishes glutathione and is most effective if given within 8-10 hours.
The Rumack-Matthew nomogram uses a serum acetaminophen level drawn at least 4 hours post-ingestion to predict toxicity.
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Nursing priorities
What to do, in order
Determine the exact dose, formulation, and time of ingestion immediately.
Obtain a serum acetaminophen level no earlier than 4 hours after ingestion to plot on the nomogram.
Administer activated charcoal if the child presents within about 1 hour and the airway is protected.
Administer N-acetylcysteine (oral or IV) as ordered without delay when toxicity is likely.
Monitor liver function tests, PT/INR, ammonia, and renal function and assess for bleeding.
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Red flags — report now
Escalate immediately
Do not delay N-acetylcysteine waiting for a level when ingestion was large or time is uncertain; the antidote loses efficacy after 8-10 hours.
Jaundice, confusion, bleeding, or rising INR signal hepatic failure and require urgent escalation.
Never give activated charcoal to a child with a decreased level of consciousness or unprotected airway (aspiration risk).
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Labs & values
Numbers to know
Serum acetaminophen level (draw at 4+ hours, plot on Rumack-Matthew nomogram)
ALT/AST: normal roughly under 40 U/L (rise with hepatotoxicity)
PT/INR: INR ~1.0 normal (prolonged with liver injury)
Bilirubin and ammonia (elevated in liver failure)
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Patient teaching
What patients must know
Store all medications, including liquid pediatric products, locked and out of a child's reach.
Use only the dosing device that comes with the product and dose by the child's weight, not age alone.
Do not combine multiple products that both contain acetaminophen, as doses add up.
Call Poison Control at 1-800-222-1222 immediately for any suspected overdose, even before symptoms appear.
❓ Acetaminophen Poisoning in Children: NCLEX FAQs
What are the priority nursing interventions for Acetaminophen Poisoning in Children?
Determine the exact dose, formulation, and time of ingestion immediately. Obtain a serum acetaminophen level no earlier than 4 hours after ingestion to plot on the nomogram. Administer activated charcoal if the child presents within about 1 hour and the airway is protected. Administer N-acetylcysteine (oral or IV) as ordered without delay when toxicity is likely.
What are the warning signs of Acetaminophen Poisoning in Children a nurse must report?
Do not delay N-acetylcysteine waiting for a level when ingestion was large or time is uncertain; the antidote loses efficacy after 8-10 hours. Jaundice, confusion, bleeding, or rising INR signal hepatic failure and require urgent escalation. Never give activated charcoal to a child with a decreased level of consciousness or unprotected airway (aspiration risk).
What do I need to know about Acetaminophen Poisoning in Children for the NCLEX?
Toxicity is dose-related; a single acute ingestion of about 150 mg/kg or more is potentially toxic. Clinical course has four stages: early stage may be asymptomatic or show only nausea, vomiting, and malaise. Stage 2 (24-72 hours) brings right upper quadrant pain and rising liver enzymes despite the child feeling better. Peak hepatotoxicity (stage 3) occurs at 72-96 hours with jaundice, coagulopathy, and possible liver failure.
What patient teaching is important for Acetaminophen Poisoning in Children?
Store all medications, including liquid pediatric products, locked and out of a child's reach. Use only the dosing device that comes with the product and dose by the child's weight, not age alone. Do not combine multiple products that both contain acetaminophen, as doses add up. Call Poison Control at 1-800-222-1222 immediately for any suspected overdose, even before symptoms appear.
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Quick Tip
Toxicity is dose-related; a single acute ingestion of about 150 mg/kg or more is potentially toxic.