Many medications, toxins, and other substances can have profoundly significant, even letal, effects at a high-enough dose. Identifying the 'poisoned patient', determining the cause, and treating appropriately are important skills for health care providers. 


Ask for help; overdoses can be very difficult to

The majority of intoxications can managed supportively.


Common Toxins


Numerous chemicals can have impoact on health, either acutely or chronically. Some common toxins important for health care providers to be aware of include:



Other Toxins


Information can be gathered from Poisonex or from company websites. A key number to call is Poison Control, staffed largely by nurses and pharmacists.


"When an activity poses a threat to human health or the environment, precautionary measures should be taken, even when the cause and effect relationship is not fully established scientifically..." the Precautionary Principle




Toxidromes are combinations of vital signs and clinically obvious end-organ manifestations, including pupils and skin. They provide clues to diagnosis and direct  management.

However, it is important not to depend on them. Not all toxins cause a toxidrome, mixed ingestions can cancel each other out, and underlying medical conditions or regular prescription meds can influence manifestations. The differential includes other types of shock.


  • sympathomimetic
  • sympatholytic
  • anticholinergic
  • cholinergic
  • opioid

sympathomimetic toxidrome

SNS overstimulation results in an elevation of vitals: fight or flight

  • diaphoresis
  • hypertension
  • tachycardia or arrhythmias
  • increased respiratory rate
  • mydriasis
  • hyperreflexia
  • delusions, paranoia

sympatholytic toxidrome

  • hypotension
  • bradycardia
  • hypothermia (less movement, lying on cold floors)
  • decreased RR (indication for narcan)
  • miosis
  • decreased BS

anticholinergic toxidrome

most common; results from removal of vagal tone

  • big, dilated pupils
  • tachycardia
  • hypertension
  • dry mouth
  • dry, hot skin
  • tachycardia, arrhythmias, CV collapse
  • mydriasis
  • decreased bowel sounds, urinary retention
  • altered mental status
  • delerium, hallucinations
  • seizures, coma
  • ECG: sinus tachy, prolonged PR, QRS, QT intervals; RBBB, ST elevation in leads V1-V3

mad as a hatter, red as a beet, dry as a bone

cholinergic toxidrome

nicotinic and muscarinic effect

  • fluids pouring from every orifice: salivation, lacrimation, urination, diaphoresis, bronchorrea (what kills people early on)
  • bradycardia, hypotension
  • emesis, urinary and fecal incontinence
  • neuro: miosis, altered LOC, seizures


causes: organophosphate and carbamate pesticides, some mushrooms, nerve gas

people often die of bronchorrhea

atropine an antidote

opioid toxidrome

  • decrease in vitals
  • stupor, seizures, coma, respiratory depression
  • miosis,
  • dry skin
  • urinary retention
  • decreased bowel sounds
  • hyporeflexia

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The poisoned patient

Ensure healthcare/rescuer safety - acids/bases, gases, organophosphates

  • history
  • physical exam
  • lab investigations


collateral history is extremely important

medical history

precription medications -

  • drug ingested
  • amount
  • time frame
  • route
  • circumstances (intentional vs unintentional; occupational, recreational, suicidal, accidental)



did they spit it out? swallowed? vomited?

Physical Exam

Be brief but attentive. Assume nothing Examine:

  • pupils
  • lungs
  • heart
  • GI 
  • mucous membranes: dry or wet (armpit specific for ruling out pure anticholinergic
  • skin
  • GU: are they making urine?

in particular, pay attention to:

  • signs of trauma, track marks


  • GCS, HR, BP, O2 sat, temp, chem strip




blood tests

  • CBC-diff
  • electrolytes
  • urea and sCR (can patients clear the drug)
  • glucose
  • ALT, AST, ALP, billi, INR, PTT
  • Ca, Mg, PO4
  • beta hCG (if applicable)
  • osmolar gap
  • anion gap

tox screen (within 72 hours) - be aware of many false positives or negatives

  • ethanol
  • acetaminophen 
  • salicylates
  • methanol
  • ethylene glycol
  • digoxin
  • other medication levels

urine tox screen has limited utility

arterial blood gas (debatable)



CT head

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When contemplating treatment, consider:

  • ABCs
  • preventing absorption
  • enhancing elimination


Perform a complete set of vitals  (HR/BP/T/GCS/O2 sat) and immediately correct life-threatening abnormailites. 

Airway/breathing: intubate if GCS <8, with severe hypoxia or hypercapnia, and with hemodynamic instability

Circulation: 2 large bore IV's, equipped with pressure bags

coma/depressed level of consciousness

Important antidotes to consider (DON'T Forget):

  • dextrose (hypoglycemia)
  • oxygen
  • naloxone: use for respiratory depression, not CNS (people who go into withdrawal will take off)
  • thiamine
  • flumazenil (benzodiazepine antidote)

anticiapte seizures/ CV collapse


secondary survey

Complete exam

  • signs of trauma
  • pupils
  • skin: temp, colour
  • bowel sounds
  • CNS

other A: antibiotics: 1qm Ceftriaxone

Prevent absorption

Induction of emesis is no longer recommended


activated charcoal

  • most effective within a couple hours
  • liquid meds likely no benefit
  • does not bind Li, Pb, Fe, alcohols
  • children do not like it
  • vomiting and aspiration is an important potential risk
  • take at 0.5-1.0 g/kg


gastric lavage has limited indications, and can be especially difficult in children.

  • ingestion within an hour
  • lethal drug for which there is no antidote


whole bowel irrigation

  • NG tube; 35ml/kg/hr
  • Go-Lytely until clear rectal effluent
  • slow release/enteric coated
  • toxins that are not adsorbed to AC (ie iron)
  • body packers/stuffers (ie drug mules)
  • contraindications: airway, GI pathology, hemodynamic instability

Enhance elimination

urine alkalinization (for salicylates)

multiple dose activated charcoal (gut dialysis)


  • alcohols, ASA, lithium, theophylline


  • theophylline, carbamezapine, phenytoin, barbituates

caustic injestion: no charcoal (don't cause vomiting); don't cause lavage

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Resources and References


US National Library of Medicine ToxNet