Toxicology Mnemonic Challenge

aka Toxicology Conundrum 054

There are multiple learning tools used as an adjunctive aide memoire such as a pattern of letters, ideas, or associations. Here are a number of Toxicological related mnemonics used with varying frequency throughout the conundrums. Let us know if you have any more to add…

Agents Affecting Pupil Size

Miosis (COPS)
  • Cholinergic, clonidine, carbamates
  • Opioids, organophosphates
  • Phenothiazines (antipsychotics), pilocarpine, pontine haemorrhage
  • Sedative – hypnotics
Mydriasis (SAW)
  • Sympathomimetics
  • Anticholinergics
  • Withdrawal syndromes

Agents Causing Coma or Seizures

  • Lead, lithium
  • Ethanol, ethylene glycol, ethchlorvyol
  • Tricyclic antidepressants, thallium, toluene
  • Heroin, hemlock, hepatic encephalopathy, heavy metals, hydrogen sulphide, hypoglycaemics
  • Arsenic, antidepressants, anticonvulsants, antipsychotics, antihistamines
  • Rohypnol (sedative hypnotics), risperidone
  • Gamma-hydroxybutyrate (GHB)
  • Isoniazid, insulin
  • Carbon monoxide, cyanide, clonidine
  • Organophosphates, oral hypoglycaemics
  • Tricyclic antidepressants
  • Isoniazid, insulin
  • Sympathomimetics, strychnine, salicylates
  • Camphor, cocaine, carbon monoxide, cyanide, chlorinated hydrocarbons
  • Amphetamines, anticholinergics
  • Methylxanthines (theophylline, caffeine), methanol
  • Phencyclidine (PCP), propranolol
  • Benzodiazepine withdrawal, botanicals (water hemlock, nicotine), bupropion, GHB
  • Ethanol withdrawal, ethylene glycol
  • Lithium, lidocaine
  • Lead, lindane

Cholinergic Toxidrome

Muscarinic (DUMBELLS)

Cholinergic Toxidrome (Flashcard)

  • Diarrhoea, diaphoresis
  • Urination
  • Miosis
  • Bradycardia
  • Emesis
  • Lacrimation
  • Lethargic
  • Salivation
Nicotinic: Days of the Week
  • Mydriasis
  • Tachycardia
  • Weakness
  • Tremors
  • Fasiculations
  • Seizures
  • Somnolent


Reveal Mnemonics

Anticholinergic Toxidrome (Flashcard)

  • Blind as a bat;
  • Mad as a hatter;
  • Red as a beet;
  • Hot as Hades/Hell/Desert;
  • Dry as a bone;
  • The bowel and bladder lose their tone, and the heart runs alone.


  • Can’t See (blurred vision);
  • Can’t pee (urinary retention);
  • Can’t spit (dry mouth);
  • Can’t Shit (constipated)

Substances that cause bradycardia.

  • Propranolol (Beta blockers), poppies (opiates), propoxyphene, physostigmine
  • Anticholinesterase drugs (I.e. cholinergics like physostigmine), antiarrythmics
  • Clonidine, calcium channel blockers
  • Ethanol or other alcohols
  • Digoxin, digitalis

Substances that cause tachycardia.

  • Free Base or other forms of cocaine, Freon
  • Anticholinergics, antihistamines, antipsychotics, amphetamines, alcohol withdrawal
  • Sympathomimetics (cocaine, caffeine, amphetamines, phencyclidine [PCP]), solvent abuse, strychnine
  • Theophylline, tricyclic antidepressants, thyroid hormones

Substances that cause hypothermia.

  • Carbon monoxide
  • Opioids
  • Oral hypoglycaemics, insulin
  • Liquor (alcohols)
  • Sedative-hypnotics

Substances that cause hyperthermia.

  • Neuroleptic malignant syndrome, nicotine
  • Antihistamines, alcohol withdrawal
  • Salicylates, sympathomimetics, serotonin syndrome
  • Anticholinergics, antidepressants, antipsychotics

Substances that cause hypotension

  • Clonidine, calcium channel blockers
  • Rodenticides (containing arsenic, cyanide)
  • Antidepressants, aminophylline, antihypertensives
  • Sedative-hypnotics
  • Heroin or other opioids

Substances causing hypertension.

  • Cocaine
  • Thyroid supplements
  • Sympathomimetics
  • Caffeine
  • Anticholinergics, amphetamines
  • Nicotine

Substances that cause hyperventilation.

  • PCP, paraquat pneumonitis, phosgene
  • Acetylsalicylic acid (ASA) and other salicylates
  • Noncardiogenic pulmonary oedema, nerve agents
  • Toxin-induced metabolic acidosis

Substances that cause hypoventilation

  • Sedative-hypnotics (barbiturates, benzodiazepines)
  • Liquor (alcohols)
  • Opioids
  • Weed (marijuana)

Substances causing a wide anion-gap acidosis.

  • Cyanide, carbon monoxide, colchicine
  • Alcohol, alcoholic ketoacidosis, acetaminophen (in large doses)
  • Toluene
  • Methanol, metformin
  • Uraemia
  • Diabetic Ketoacidosis
  • Paraldehyde
  • Isoniazid, iron
  • Lactic acidosis
  • Ethylene glycol
  • Salicylates

Potentially lethal toxins where early activated charcoal maybe indicated.

Killer C’s
  • Cyanide
  • Colchicine
  • Calcium channel blockers
  • Cyclic antidepressants
  • Cardiac glycosides
  • Cyclopeptide mushrooms
  • Cocaine
  • Cicutoxin (water hemlock)
  • Salicylates

Substances that do not bind to charcoal.

  • Pesticides
  • Heavy metals
  • Acids/alkalis/alcohols
  • Iron
  • Lithium
  • Solvents

Dialysable Toxins.

  • Phenobarbitol
  • Lithium
  • Acidosis
  • Salicylates
  • Metformin
  • Alcohols
  • Theophylline
  • Valproic Acid

Substances amenable to multi-dose activated charcoal.

  • Aminophylline / theophylline
  • Barbiturates
  • Carbamazepine / concretion forming drugs (salicylates)
  • Dapsone
  • Quinine


Toxicology Conundrum

Dr Neil Long BMBS FACEM FRCEM FRCPC. Emergency Physician at Kelowna hospital, British Columbia. Loves the misery of alpine climbing and working in austere environments (namely tertiary trauma centres). Supporter of FOAMed, lifelong education and trying to find that elusive peak performance.


    • Sorry, just looked at the post; it says anticholinesterase drugs – it’s a bit like a double negative, It’s referring to cholinergic drugs that have an anticholinesterase activity. I’ve changed the post slightly for clarification.

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