Toxodromes

A toxidrome (toxic syndrome) is a specific constellation of clinical signs and symptoms caused by an overdose or exposure to a particular class of toxins or drugs. There are five major toxidromes:

This toxidrome involves overstimulation of the sympathetic nervous system, mimicking the body's “fight or flight” response.

• Common Agents
  • Cocaine
  • Amphetamines
  • Methylphenidate (Ritalin/Adderall)
  • MDMA (Ecstasy)
  • Bath salts
• Key Symptoms
  • Agitation, anxiety, paranoia, hyperactivity, tremors, and seizures.
• Vital Signs & Exam
  • tachycardia
  • hypertension
  • hyperthermia
  • diaphoresis
• Eye Findings: Mydriasis

This occurs when drugs block the action of acetylcholine in the parasympathetic nervous system.

• Common Agents
  • Atropine
  • Antihistamines
  • Tricyclic antidepressants (TCAs)
  • Plants like Jimson weed.
• Key Symptoms
  • Delirium, hallucinations, confusion
  • Muscle twitching.
  • Classic mnemonic: “Mad as a hatter, blind as a bat, red as a beet, hot as a hare, dry as a bone.”
• Vital Signs & Exam:
  • Tachycardia
  • Hyperthermia
  • Dry skin and mucous membranes (no sweating)
• Eye Findings: Miosis

This toxidrome is caused by overstimulation of parasympathetic nerves due to an excess of acetylcholine.

• Common Agents
  • Organophosphates (pesticides)
  • nerve agents (e.g., Sarin)
  • Meds like physostigmine.
• Key Symptoms:
  • Mnemonic “SLUDGE: Salivation, Lacrimation, Urination, Diarrhea, Gastrointestinal cramps, and Emesis”
  • Severe cases cause pinpoint pupils, muscle fasciculations, and respiratory distress.
• Vital Signs & Exam:
  • Profuse bodily secretions
  • Bradycardia
• Eye Findings: Miosis

This toxidrome suppresses the central nervous system, mainly through the activation of mu-opioid receptors.

• Common Agents
  • Opioids: Morphine, heroin, fentanyl, oxycodone, and codeine
• Key Symptoms:
  • CNS depression ranging from extreme drowsiness to unresponsiveness or coma.
• Vital Signs & Exam:
  • Bradypnea
  • Hypotension
  • Hypothermia
• Eye Findings: Miosis

This syndrome results from the enhancement of GABA receptors, which generally slows down brain activity.

• Common Agents: Benzodiazepines (e.g., Valium, Xanax), barbiturates, ethanol (alcohol), and sleeping aids (Z-drugs). • Key Symptoms: Drowsiness, slurred speech, confusion, and ataxia (loss of coordination). • Vital Signs & Exam: Depressed breathing, decreased reflexes (hyporeflexia), and low blood pressure. Unlike opioids, pinpoint pupils are generally not a feature of this toxidrome.

1. Youtube link
2. Toxodrome clinical features
3. Toxidrome Review
4. https://www.rch.org.au/clinicalguide/guideline_index/Toxidromes_poisoning/ Toxidrome Poisioning Clinical Guide
5. Youtube link
6. Demystifying Toxodromes
7. Link
8. Common Toxodromes

[9] https://emspodcast.com/episode/toxidromes/ [10] https://www.youtube.com/watch?v=4JE0owcG85I [11] https://en.wikipedia.org/wiki/Toxidrome [12] https://foamed.ebmedicine.net/rapid-reference/toxidromes/ [13] https://chemm.hhs.gov/toxicsyndromes.htm [14] https://www.youtube.com/watch?v=UAOK66qAoBg [15] https://pmc.ncbi.nlm.nih.gov/articles/PMC12429776/ [16] https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/toxidrome [17] http://www.thegasmanhandbook.co.uk/toxidromes.html [18] https://www.jems.com/patient-care/emergency-medical-care/common-poisoning-syndromes-to-know/ [19] https://www.tldrpharmacy.com/content/a-pharmacist-friendly-introduction-to-toxicology [20] https://hospitalhandbook.ucsf.edu/content/03-toxidromes [21] https://www.lecturio.com/concepts/general-principles-of-toxidromes/ [22] https://quizlet.com/study-guides/major-toxidromes-symptoms-drugs-and-identification-ea3f9aa1-fd53-45db-a6bd-1b55d8f148e1 [23] https://pmc.ncbi.nlm.nih.gov/articles/PMC12429776/ [24] https://floridapoisoncontrol.org/healthcare-professional/toxidromes/