The purpose of this guideline is to provide clinical advice around the use of intravenous acetylcysteine in
paediatric patients at the Queensland Children’s Hospital (QCH).
Description and Indications for Use
Acetylcysteine is an effective antidote to paracetamol overdose by increasing the synthesis and availability of
glutathione and directly binding to NAPQI (N-acetyl-p-benzoquinone imine).
Acetylcysteine reduces mortality even if commenced in patients presenting with established paracetamolinduced fulminant hepatic failure. The mechanisms of action in this period may be different.
Acetylcysteine is available as a 2,000 mg / 10 mL solution for injection
Contraindications
• None
 Precautions
• Fluid restricted patients require adjustment of total volume to minimize risk of hyponatraemia,
seizure and death – seek specialist advice.
• Risk of anaphylactoid reactions is dose-related and occurs more commonly during the initial
infusion. Previous hypersensitivity reactions to Acetylcysteine do not prevent future use.
Discussion with Poison Information Centre or toxicologist is recommended.
• Nausea, vomiting and other gastrointestinal symptoms are the most common adverse effects
experienced with high dose Acetylcysteine infusions. Antiemetic therapy may be required.
• Use with caution in children with a history of asthma/bronchospasm. Close monitoring is
required.
• Use with caution in children with history of oesophageal varices and peptic ulceration as
Acetylcysteine induced vomiting can increase risk of haemorrhage.
Dose
Care must be taken in dose calculation and administration instructions. Dosage of acetylcysteine is based on
actual bodyweight with a ceiling weight of 110 kg.2 Doses are written in milligrams.
The regimen involves a two-bag infusion and both infusions should be charted by treating medical officer at
time of initiation to avoid delays in treatment.
Clinical Considerations
Adverse Reactions
Clinical effects associated with acetylcysteine administration:
• Nausea, vomiting (Common reaction with ~30% incidence.4 May require antiemetic treatment).
• Shortness of breath, wheeze.
• Rash, flushing, itchiness.
• Hypotension.
If adverse effects occur, notify medical officer. Most of the above reactions are related to the release of
histamine4 and can be managed by stopping the infusion briefly, treating any effects, and recommencing at
the same rate. An antiemetic and antihistamine may be given if required.
Consultation
Key stakeholders who reviewed this version include Pharmacist Senior – Queensland Poisons Information
Centre and Pharmacist Senior – Safety Quality
Key stakeholders who reviewed the previous version:
• Pharmacist Team Leader – Critical Care
• Senior Medical Officer, Department of Emergency Medicine
• Medical Director, Queensland Poisons Information Centre
• Manager, Queensland Poisons Information Centre
• Pharmacist Advanced – Safety and Quality
• Pharmacist Consultant – Electronic Medication Management