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 (tearing), Urination, Diarrhea, Gastrointestinal cramps, and Emesis (vomiting).”
  • 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: Morphine, heroin, fentanyl, oxycodone, and codeine. • Key Symptoms: CNS depression ranging from extreme drowsiness to unresponsiveness or coma. • Vital Signs & Exam: Severely depressed respiratory rate (bradypnea), constricted (pinpoint) pupils, low blood pressure (hypotension), and low body temperature.

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/