Patient details/sticker here:
Paracetamol Overdose in Adults, WSHT Guidelines
(revised December 2015)
In overdose paracetamol can be fatal. N-acetylcysteine (NAC, Parvolex) has proven
benefit as the ‘antidote’. If untreated, Liver damage is maximal 3-4 days after
ingestion and can develop into acute liver failure syndrome (hypoglycaemia,
coagulopathy, haemorrhage, jaundice, renal failure, cerebral oedema,
encephalopathy) & death.
Significant ingestion?
Work out ingested dose in mg/kg
Total
mg
dose
=
Patient
mg/kg
kg
weight
Initial ABCDE assessment of the patient
Is it a staggered overdose or unknown time of ingestion or a late presentation
(>8 hours)?
NO
If time of overdose is known and within 4-8 hour window take a
post overdose paracetamol level (& INR, Lactate, FBC, U&E, LFT).
Do not take levels before 4hrs.
Plot paracetamol level against treatment line (see
next page for nomogram)
Is the paracetamol level plotted above the
treatment line, therefore in the toxic range?
Disregard any additional kilos in
excess of 110kg
If pregnant, enter pre-pregnancy
not actual weight
YES, as one of the below
Ingested dose >75mg/kg/24h
YES
NO, as none of the above
YES
Take bloods: Paracetamol levels, INR, Lactate, FBC,
U&Es, LFTS and Start N-acetylcysteine treatment
immediately.
CEM standard in < 1hr
NO
Significant ingestion
Psych review before discharge, unless truly accidental. Be
aware of concealed overdose. Any disturbance to LFT/INR
may need to consider empirical treatment. Give
paracetamol OD patient information leaflet. May also need
information on Substance Misuse services.
Additional Notes:
1) Some patients may develop hypoglycaemia several hours after
Paracetamol – be aware of this
Treatment Regime: NAC infusions are weight based and
should be prescribed according to the adult dosage table
shown below. All infusions are to be diluted with 5% Dextrose.
Bag 1 (200ml 5% Dextrose): IV N-acetylcysteine (PARVOLEX)
150 mg/kg over 1 hour (max dose 16.5g)
Bag 2 (500ml 5% Dextrose):IV N-acetylcysteine (PARVOLEX)
50 mg/kg over the next 4 hours (max dose 5.5g)
Bag 3 (1000ml 5% Dextrose): IV N-acetylcysteine (PARVOLEX)
100 mg/kg over the next 16 hours (max dose 11g)
Bag 4 (1000ml 5% Dextrose): IV N-acetylcysteine (PARVOLEX)
100 mg/kg over the next 16 hours (max dose 11g)
2) Be aware of coexistent poly pharmacy overdose. All patients
should be tested for Salicylate levels and questioned about other
drug consumption
3) For patients weighing > 110 kg the antidote dose in mg/kg should
be calculated using a maximum of 110 kg, rather than actual weight
Re-check INR, creatinine, bicarb, LFT activity
(ALT/AST) after Bag 3;
While awaiting results repeat 16 hour dose (Bag 4)
4) Pregnancy: NAC dose should be calculated using the patient’s
actual pregnant weight
5) Beware renal failure may occur either in isolation or as part of
the acute liver failure spectrum – this should be managed with a
standard AKI approach
6) See over for patients wanting to self-discharge
INR <1.3 (& transaminases <3x Normal
&<2x admission level)
1. Can stop N-Acetylcysteine administration
2. If all other medical issues treated &
patient well, then needs psychiatric
referral
INR >1.3 OR transaminase activity has x2
since admission level OR the transaminase
activity is >3x ULN
1. Continue to repeat the 16 hour bags until
the INR <1.3
2. Seek specialist advice (Working hours –
Drs Rashid, Philipose, Thomson, OOH Liver unit)