Paracetamol overdose Paediatric



These guidelines relate to paediatric patients only. Click for ADULT Paracetamol overdoses.


Background

  • Hepatocellular necrosis is the major toxic effect.
  • Biochemical evidence of maximal damage may not be attained until 72 - 96 hours after ingestion.
  • Severe liver damage is defined as a peak plasma ALT exceeding 1000 u/L.
  • Those who present > 12 hours post ingestion tend to be more severely poisoned and at greater risk.
  • Acute renal tubular damage and necrosis may also occur.
  • If there is doubt about the timing or the need for treatment - treat.
  • Methionine is ineffective in patients who have been given oral activated charcoal.
  • NAC is the treatment of choice when patients are vomiting or present more than 8 hours after ingestion..

Do NOT take plasma levels within 4 hours of ingestion as they are unreliable.

But patients may give inaccurate histories. If in doubt, treat with NAC.



Treatment nomogram

Antidote ( NAC ) doses

The standard administration of NAC is a 2 stage infusion (not 3 as in adults) giving a total dose of 300 mg/kg:

200 mg/kg over 4 hours

100 mg/kg over the next 16 hours

NAC may be diluted in 5% glucose or 0.9% sodium chloride.

The volume of NAC needs to be included in the total volume of the infusion to avoid under-dosing (volumes specified in tables below are total volumes – ie. NAC volume plus fluid volume combined).

For children >20 kg body weight:
NAC Dose Dilute to
(using NaCl)
Rate and Duration
200 mg/kg Total vol. 250 mL 62.5 mL/hr for 4 hours
Infuse entire bag
100 mg/kg Total vol. 500 mL 31.25 mL /hr  for 16 hours 
Infuse the entire bag
For children ≤20 kg body weight:
NAC Dose Dilute to
(using NaCl)
Rate and Duration
200 mg/kg Total vol. 250 mL 62.5 mL/hr for 4 hours
Infuse entire bag
100 mg/kg Total vol. 250 mL 15 mL /hr  for 16 hours 
Infuse the entire bag

Please contact pharmacy if these infusion large volumes are not suitable for your patient.


Specialist advice on those with liver disease.

Patients who develop severe liver damage may merit discussion with a specialist liver unit (not necessarily a liver transplant unit). Such discussions are likely to be of greater benefit if they are held early. Patients in this category include those who have an INR greater than 3.0, an elevated plasma creatinine, evidence of acidosis or encephalopathy, hypotension (mean arterial pressure less than 60 mmHg) or pre-existing liver disease.


Adverse reactions to NAC

  • N-acetylcysteine adverse effects may be localised to infusion site or be more generalised.
  • Usually occur during the first 30 minutes of administration (large dose given rapidly).
  • Include nausea, flushing, itching, erythematous rashes, urticaria, angioedema, bronchospasm and, rarely, ↑BP or ↓BP.
  • Infusion of NAC should be stopped and an antihistamine given.
  • Once adverse effects settled, resume infusion at the lowest infusion rate (100 mg/kg over 16 hours).


Content by Dr Íomhar O' Sullivan 23/06/2000.   Reviewed by Dr ÍOS 10/07/2004 and 14/02/2007. Based upon 2007 guidelines published by the Paracetamol Information Centre and TOXBASE. Last review Prof R. O'Sullivan, Dr ÍOS20/11/18