What is the management for a child who ingested 30 tablets of paracetamol (Acetaminophen)?

Management of Pediatric Paracetamol Overdose (30 Tablets)

Both activated charcoal AND N-acetylcysteine (NAC) should be administered immediately, along with serial liver function tests (LFTs) to monitor for evolving hepatotoxicity—even if the child appears clinically normal at presentation. 1

Immediate Actions Required

1. Activated Charcoal Administration

• Give activated charcoal (1 g/kg orally) immediately if the child presents within 4 hours of ingestion, just prior to starting NAC 1, 2
• Activated charcoal is most effective within 1-2 hours but retains benefit up to 4 hours post-ingestion 1
• In massive overdoses (≥40g), activated charcoal given within 4 hours significantly reduces paracetamol concentrations (ratio 1.4 vs 2.2, p<0.0001) and hepatotoxicity risk (OR 0.12) 3
• Do not delay NAC while giving activated charcoal—administer charcoal just before NAC infusion begins 1, 2

2. N-Acetylcysteine (NAC) Therapy

Start NAC immediately without waiting for laboratory results if:

• The ingested dose is potentially hepatotoxic (≥150 mg/kg or ≥10g total, whichever is less) 1, 4
• Time of ingestion is unknown or unreliable 2, 5
• The child presents >8 hours post-ingestion 1, 5

NAC dosing regimen (IV): 1, 2, 5

• Loading dose: 150 mg/kg over 15 minutes (or 4 hours in newer two-bag regimen)
• Second dose: 50 mg/kg over 4 hours (or combined with maintenance in two-bag regimen)
• Third dose: 100 mg/kg over 16 hours
• Total treatment time: 21 hours minimum

3. Serial Laboratory Monitoring

Obtain immediately: 1

• Serum paracetamol concentration (must be drawn ≥4 hours post-ingestion for nomogram interpretation)
• Baseline liver function tests (AST, ALT)
• Prothrombin time/INR
• Creatinine

Serial monitoring: 1

• Repeat LFTs every 12-24 hours until trending downward
• Continue monitoring even if initial labs are normal—hepatotoxicity peaks at 3-4 days post-ingestion 6

Risk Stratification Using Rumack-Matthew Nomogram

The nomogram ONLY applies if: 1, 5

• Single acute ingestion (not repeated doses)
• Known time of ingestion
• Paracetamol level drawn 4-24 hours post-ingestion

If paracetamol concentration plots above the "possible toxicity" line (≥150 mg/L at 4 hours or ≥50 mg/L at 12 hours), continue full NAC course. 1, 4

Critical Timing Considerations

NAC efficacy is time-dependent: 1

• Within 8 hours: 2.9% risk of severe hepatotoxicity
• Within 10 hours: 6.1% risk
• 10-24 hours: 26.4% risk
• Even after 24 hours, NAC still reduces mortality (from 80% to 52%) and should never be withheld 1

Special Scenarios Requiring Modified Management

If the Child Appears "Normal"

Clinical appearance is unreliable—paracetamol hepatotoxicity is delayed, with maximum liver injury occurring 3-4 days post-ingestion 6. Early presentation with normal examination does NOT exclude need for treatment 1.

Massive Overdose (≥30g or ≥500 mg/kg)

• Consider increased NAC dosing (double the maintenance dose: 200 mg/kg over 16 hours instead of 100 mg/kg) 1, 7, 3
• Patients with paracetamol ratio ≥2 (concentration double the nomogram line) who received increased acetylcysteine had 73% reduction in hepatotoxicity (OR 0.27) 3

Unknown Time of Ingestion

• Start NAC immediately 1, 2, 5
• Obtain paracetamol level urgently—if detectable, continue full NAC course 1
• Monitor LFTs serially regardless of initial paracetamol level 1

When to Extend NAC Beyond 21 Hours

Continue NAC if: 1

• Paracetamol level remains detectable
• AST or ALT elevated above normal or rising
• INR elevated
• Patient presented >24 hours post-ingestion
• Delayed presentation with any evidence of hepatotoxicity

Common Pitfalls to Avoid

1. Do not wait for paracetamol levels before starting NAC if presentation is >8 hours post-ingestion or dose is clearly toxic 1, 5
2. Do not rely on the nomogram if timing is uncertain—treat empirically 1
3. Do not assume safety based on normal initial LFTs—hepatotoxicity develops over days 1, 6
4. Do not withhold activated charcoal because NAC will be given—they work synergistically when charcoal is given first 1, 3
5. Low or undetectable paracetamol levels do NOT rule out toxicity if ingestion was remote or occurred over multiple doses 1, 4

Answer to Original Question

Both A and B are correct and should be done simultaneously:

• A (Serial LFTs): Essential for detecting evolving hepatotoxicity, which may not manifest for 24-72 hours 1, 6
• B (NAC & Activated Charcoal): Both should be given immediately—activated charcoal first (if within 4 hours), followed immediately by NAC infusion 1, 2, 3

The child appearing "normal" is expected early after ingestion and does not change management—paracetamol hepatotoxicity is characteristically delayed 6.