Poisoning - Overview


These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full CAHS clinical disclaimer.


To guide PCH Emergency Department (ED) staff with the assessment and management of poisoning or overdose in children.

This guideline provides an outline of the general approach to poisoning. Specific information about poisoning presentations can be obtained from Poisons Information: 13 11 26 or refer to the Toxicology and Toxinology – Therapeutic Guidelines.


  • The vast majority of morbidity and mortality in toxicology arises from complication of the poisoning not the poisoning itself, particularly aspiration due to sedation
  • Good supportive care is the best way to prevent complications
  • Poisonings follow a highly predictable path
  • Consider child protection concerns including intentional poisoning or neglectful supervision in significant and/or unusual overdose or if frequent concerning presentations.
  • All ingestion presentations in children under 2 years must have an Early Childhood Injury Proforma completed (MR301.3) (internal WA Health only)
  • Risk assessment is an essential cognitive step during assessment that outlines ongoing care

  • If information is unclear always base the risk assessment upon a 'worse case scenario'
  • Know your list of '2 pills can kill' in a toddler (see table 1 below)
    • Most accidental paediatric ingestions are only 1-2 tablets and a risk assessment will be low. Nevertheless, there are some toxins which can kill a young child with a very small exposure. These should be aggressively managed with early senior advice and/or toxicology service input.

The general approach to all poisonings should follow the RRSIDEAD format:

R Resuscitation
R Risk Assessment
S Supportive Care
D Decontamination
E Enhanced Elimination
A Antidotes
D Disposition



Follow traditional ABC approach with modification:

  • Airway
  • Breathing
  • Circulation
  • Control/Correct
    • Seizures with midazolam – Medication Management Manual (internal WA Health only) (phenytoin contraindicated)
    • Hypothermia
    • Hyperthermia
      • Temperature > 38.5º requires core monitoring
      • Temperature > 39.5° is an indication for intubation, ventilation and paralysis.

Risk assessment

The following five factors will provide an accurate prediction of clinical course, potential complications and time coarse of poisoning to direct management.

1. Agent/s

2. Dose

3. Time of ingestion

  • Use the latest possible time if uncertain

4. Patient factors

  • Weight
  • Comorbidities that may affect prognosis, for example:
    • Heart disease complicating calcium channel overdose
    • Morbid obesity affecting airway patency

5. Clinical status (features and progress)

  • Agents commonly affect the autonomic, central nervous system (CNS) and neuromuscular systems and may produce a recognisable 'toxidrome'
  • Does the clinical presentation of the patient fit with the predictable profile of the overdose?

Table 1: Toxidromes1

    Anticholinergic Sympathomimetic Serotonergic 
Examples   e.g. Antihistamines


Street amphetamines


selective serotonin reuptake inhibitors / serotonin and noradrenaline reuptake inhibitors, tricyclic antidepressants, monoamine oxidase inhibitors

Autonomic Vital Signs  Elevated Elevated Elevated
  Temperature  Elevated
  Pupils Dilated Dilated
  Skin/mucous membranes  Flushed, dry Flushed, sweaty Flushed, sweaty
CNS Mental status Agitated, delirium Agitated, euphoria Agitated, coma
  Seizures Rarely Yes Yes
Neuromuscular  Tone Normal Increased/rigidity Increased/rigidity
  Reflexes Normal Hyperreflexic Hyperreflexic/clonus
Complications   Urinary retention
Injury to self
Severe hypertension
Myocardial infarction
Pulmonary oedema
Subarachnoid haemorrhage

Supportive care and monitoring1

  • Supportive care is tailored to the risk assessment and may involve:
    • IV hydration
    • Control of agitation and seizures with titrated benzodiazepines
    • Ensuring normoglycaemia
    • Bladder care (especially monitoring for urinary retention).


Investigations are done for either specific purposes, to identify occult overdoses, or specific tests to determine the presence or level of a known ingestant.


  • 12 lead Electrocardiogram (ECG)
    • Wide QRS (sodium channel blockade)
    • Long QT (potassium channel blockade, anti-psychotic overdose)
    • Heart blocks (calcium channel and beta blockers/calcium channel poisoning
  • Serum Paracetamol level (4 hours)
  • Blood glucose level (BGL).


  • Drug levels
    • Paracetamol (in known ingestion)
    • Iron
    • Alcohols
    • Lithium
    • Salicylate
    • Theophylline
    • Anti-epileptics

Other adjunctive tests as indicated

  • Blood gas:
    • High anion gap metabolic acidosis
      • Tricyclic antidepressants
      • Salicylates (late)
      • Iron
      • Toxic alcohol
      • Metformin
    • Respiratory alkalosis
      • Salicylates
    • Respiratory acidosis
      • Sedatives.

  • Abdominal X-ray:
    • Confirmation of iron or other heavy metal ingestion.
  • Blood tests:
    • Liver Function Tests (delayed paracetamol)
    • Urea Electrolytes and Creatinine
    • International Normalised Ratio (INR) (Warfarin, delayed paracetamol)


  • Consider but rarely required
    • Activated charcoal
      • Will not bind to hydrocarbons or alcohol, corrosives and metals
      • Reserved for life threatening intoxications in which other measures are not expected to result in a good outcome
      • Contraindicated in un-intubated patient if decreased conscious level, vomiting or seizures are expected
      • Can be considered where the toxin is likely to remain in the gastrointestinal tract (generally within the first hour post ingestion for most agents)
    • Other methods: e.g. whole bowel irrigation - should not be instigated in the ED and should only be commenced on advice of Poisons Information.

Enhanced elimination

  • Consider but rarely required
    • Techniques include: multiple dose activated charcoal, urinary alkalinisation, haemodialysis, haemofiltration, charcoal haemoperfusion.


  • The risk assessment should determine if the potential benefit outweighs the possible adverse effects of the antidote.
Antidote Poison
N-acetylcysteine Paracetamol
Naloxone Opiates
Flumazenil Benzodiazapines
Desferrioxamine Iron
Sodium Bicarbonate Tricyclic antidepressants (TCA)


  • The disposition will be determined by:
    • The clinical risk assessment of the overdose
    • The psychiatric safety of the patient (for deliberate overdoses)
    • Other safety factors (parental neglect or drug use, domestic issues)
  • Children should not be discharged home at night unless the risk assessment determines that the overdose is trivial and not requiring any form of observation.

Discharge home with parental supervision

  • Trivial overdose with no requirement for observation
  • Ensure safety issues such as accessibility to tablets are addressed and provide parents with Kidsafe resources
  • Low risk overdose with minimal potential for deterioration during day-time hours
  • Parents must be able to return to ED in the event of deterioration.

Emergency Short Stay Unit

  • Accidental overdoses
  • Stable patient with low-risk overdose requiring observation
  • Low risk overdose with minimal potential for deterioration during night hours.

Medical ward

  • Stable patient requiring medical or antidote therapy
  • Any suspicion of non-accidental injury (NAI)


  • Unstable or intubated patient

Psychiatric ward

  • Medically cleared patient deemed at risk of deliberate self harm

Nursing care

  • Record a full set of observation on the Observation and Response Chart, with additional information to be recorded on the Clinical Comments chart.
  • Record a full set of neurological observations.
  • Frequency of observations can be dependent on the substance ingested.
  • A minimum of hourly observations including full neurological observations (FNOs) should be recorded whilst in the ED.
  • Any significant changes should be reported immediately to the medical team.
  • Continuous cardiac monitoring if clinically indicated.
  • Consider topical local anaesthetic e.g., lidocaine (lignocaine) with prilocaine (EMLA®) if an IV may be required.
  • Strict, accurate fluid balance monitoring.
  • Urinalysis for toxicology drug screen.
  • Nursing care specific to the presentation.

Two Tablets - Potentially Lethal to a 10kg Child2


Principle features of severe toxicity


  • Amphetamine

  • Metamphetamine

  • MDMA (ecstacy)




Calcium Channel Blockers

  • Diltiazem CD

  • Verapamil SR

Delayed onset of bradycardia
Conduction defects
Refractory shock


Rapid onset of coma
Cardiovascular collapse


Ventricular tachycardia


  • Oxycodone

  • Methadone

  • Morphine Sulphate

  • Diphenoxylate/Atropine

Coma, respiratory arrest
Note: May be delayed with diphenoxylate/atropine and controlled release morphine


Ventricular tachycardia


  • Glibenclamide

  • Glibenclamide/Metformin

  • Gliclazide

  • Glimepiride

Note: Onset may be delayed up to eight hours.


Supraventricular tachycardia

Tricyclic antidepressants

  • Dothiepin

Ventricular tachycardia

Venlafaxine XR


Non-pharmaceutical agents considered potentially lethal to children1

Agent Dose of concern for 10 kg child Clinical effects
Organophosphate and carbamate insecticides
Single sip

Cholinergic symptoms
Depressed level of consciousness

Paraquat/Diquat Sip Oro-pharyngeal burns
Multiple organ failure
Pulmonary fibrosis


  • Solvents
  • Eucalyptus oil
  • Kerosene
Sip Rapid depressed level of consciousness
Aspiration pneumonia

5mL of 100%

Rapid depressed level of consciousness


  • Sodium hydroxide
  • Strong acids
  Gastro-oesophageal injury including perforation

One mothball

NB: Most mothballs contain paradichlorbenzene, which is non-toxic after a single accidental ingestion
  Rapid onset of generalised muscle spasm
Death by respiratory failure


  1. Murray L, Little M, Pascu O and Hoggett K. Toxicology Handbook. 3rd Edition. Chatswood, NSW: Elsevier Australia; 2015. Available from: Toxicology Handbook - ClinicalKey (health.wa.gov.au) 
  2. McCoubrie D, Murray L, Daly FFS and Little M. Toxicology case of the month: ingestion of two unidentified tablets by a toddler. Emerg Medicine J 2006; 23: 718-720
  3. Bar-Oz B, Levichek Z and Koren G. Medications That Can Be Fatal For a toddler with One Tablet or Teaspoon. Paediatric Drugs 2004; 6 (2): 123-126

Endorsed by:  CAHS Drug and Therapeutics Committee  Date: Apr 2022

 Review date:  Nov 2023

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