Toxidrome Identification Pathway

The toxidrome from the bedside picture, and the resuscitation that goes with it · v1.1

  • Enter the vital signs and the examination findings.
  • The categories fill in from the numbers; change one by hand where the reading does not match the patient in front of you.
  • You get the toxidrome that best fits the pattern, named, and the empirical resuscitation to start on before any screen has come back.
  • It points to a syndrome, not to a named agent.

  • Antidote doses for anybody under 18. Every figure it prints, atropine, naloxone, physostigmine and cyproheptadine included, is an adult dose.
  • Poisonings that produce no recognisable toxidrome. Paracetamol, salicylate and the toxic alcohols are found on levels rather than on a pattern, and no management for them is printed here.
  • Naming the agent. That needs the history and the toxicology screen; the pattern gets you to a class.
  • Neuroleptic malignant syndrome, which imitates the serotonin pattern. The pearls separate the two and the pathway prints no management for it.

1. Demographics

2. Vital Signs

Enter the numbers and the categories below fill in on their own. Change one by hand if the reading does not match the patient in front of you.

3. Physical Examination

Fields marked with ● are auto-populated from vitals above.

Clinical Context & Pearls

A poisoned patient is recognised by pattern long before any laboratory can name the agent. That pattern is the toxidrome, and it is usually enough to start the right resuscitation on. The agent can be established later; the treatment cannot wait for it.

1. The Anticholinergic Toxidrome

What it is: Blockade of muscarinic receptors (e.g., antihistamines, tricyclic antidepressants, atropine, Datura species).

Bedside Pearl: Remember the mnemonic: "Mad as a hatter (delirium), blind as a bat (mydriasis), red as a beet (flushed), hot as a hare (hyperthermia), dry as a bone (dry skin/mucosa)."

Indian Context: Datura stramonium poisoning is relatively common in rural India, often consumed accidentally or for deliberate self-harm. The presence of completely dry axillae is a very reliable physical sign separating it from sympathomimetic toxicity.

2. Sympathomimetic vs. Anticholinergic

These two look alike at the foot of the bed: tachycardia, hypertension, dilated pupils, agitation. Two findings separate them.

  • Skin: Sympathomimetics cause profound sweating (diaphoresis). Anticholinergics cause bone-dry skin. Check the patient's armpits.
  • Bowel Sounds: Hyperactive in sympathomimetic toxicity, hypoactive or absent in anticholinergic toxicity.

3. The Cholinergic Toxidrome

What it is: Excess acetylcholine at muscarinic and nicotinic receptors, classic for organophosphorus (OP) or carbamate insecticides.

Why it matters: Death comes from bronchorrhoea and from paralysis of the respiratory muscles. The patient drowns in secretions. Treatment is large and rapidly escalating doses of atropine, titrated to one endpoint alone: the clearing of the crackles.

4. Serotonin Syndrome

What it is: Excess serotonergic activity in the central and peripheral nervous systems, often from combining medications (e.g., SSRIs with tramadol, linezolid, or dextromethorphan).

Bedside Pearl: The hallmark physical finding is lower extremity hyperreflexia and inducible or spontaneous clonus. That is what separates it from neuroleptic malignant syndrome, where the rigidity is of the lead-pipe kind and is generalised.

Practice advisory: the coma cocktail is obsolete
Unconscious patients were once given a standing cocktail of D50, naloxone, thiamine and flumazenil, whatever the history. Treat what you have reason to treat instead. Flumazenil in particular is not given routinely, because in a mixed overdose or in somebody who takes benzodiazepines regularly it can precipitate seizures that are then very difficult to stop.
Abbreviations ABC (Airway, Breathing, Circulation) · BMI (Body Mass Index) · BP (Blood Pressure) · CK (Creatine Kinase) · CNS (Central Nervous System) · D50 (50% Dextrose) · ECG (Electrocardiogram) · HDU (High Dependency Unit) · HR (Heart Rate) · HTN (Hypertension) · ICU (Intensive Care Unit) · IM (Intramuscular) · IV (Intravenous) · NG (Nasogastric) · OP (Organophosphorus) · OT (Operating Theatre) · PPE (Personal Protective Equipment) · QRS (QRS Complex of the Electrocardiogram) · QTc (Corrected QT Interval) · RR (Respiratory Rate) · SSRI (Selective Serotonin Reuptake Inhibitor) · TCA (Tricyclic Antidepressant)
References
  1. Mokhlesi B, et al. Adult toxicology in critical care: Part I: general approach to the intoxicated patient. Chest. 2003;123(2):577-592. PMID 12576382.
  2. Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005;352(11):1112-1120. PMID 15784664.
  3. Pillay VV. Modern Medical Toxicology. 4th ed. New Delhi, India: Jaypee Brothers Medical Publishers; 2013.
  4. Hoffman RS, et al. Goldfrank's Toxicologic Emergencies. 11th ed. McGraw-Hill Education; 2019.
  5. Dunkley EJ, Isbister GK, Sibbritt D, Dawson AH, Whyte IM. The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM. 2003;96(9):635-642. PMID 12925718.
  6. Dawson AH, Buckley NA. Pharmacological management of anticholinergic delirium: theory, evidence and practice. Br J Clin Pharmacol. 2016;81(3):516-524. PMID 26589572.
  7. Seger DL. Flumazenil: treatment or toxin? J Toxicol Clin Toxicol. 2004;42(2):209-216. PMID 15214628.
  8. Peter JV, Sudarsan TI, Moran JL. Clinical features of organophosphate poisoning: a review of different classification systems and approaches. Indian J Crit Care Med. 2014;18(11):735-745. PMID 25425841.
  9. Srinivas Rao Ch, Venkateswarlu V, Surender T, Eddleston M, Buckley NA. Pesticide poisoning in south India: opportunities for prevention and improved medical management. Trop Med Int Health. 2005;10(6):581-588. PMID 15941422.

One entry was withdrawn on 28 August 2026. It read Sharma SK, et al. Guidelines for the management of pesticide poisoning in India. Indian J Crit Care Med. 2011;15(3):141-152. That citation resolves in PubMed to a different paper entirely: Arun Babu T, Alveolar recruitment maneuvers in ventilated children: caution required, Indian J Crit Care Med 2011;15(2):141 (PMID 21814385). No paper of the cited title could be found. Two traceable Indian sources take its place.

How to Cite This Tool

DOIhttps://doi.org/10.5281/zenodo.22401655

AMA Style:Umakanth S. Toxidrome Identification Pathway. Version 1.1. MEDiscuss Clinical Decision Support System. Published 2026. Accessed . https://mediscuss.org/cdss/toxidrome-id. doi:10.5281/zenodo.22401655

Vancouver Style:Umakanth S. Toxidrome Identification Pathway [Internet]. Version 1.1. MEDiscuss.org; 2026 [cited ]. Available from: https://mediscuss.org/cdss/toxidrome-id. doi:10.5281/zenodo.22401655

Disclaimer and scope
Disclaimer: This decision-support system is written for healthcare professionals. It does not substitute clinical judgment, and the treating physician retains absolute responsibility for every diagnostic, dosing and therapeutic decision. The algorithms are built on the evidence as it stands, and the evidence moves. Verify the output against your current institutional protocol, and against the patient in front of you.
© 2026 MEDiscuss.org. All rights reserved. Provided free of charge for clinical use. Unauthorised reproduction or redistribution is strictly prohibited.
Category Acute ResuscitationPathway
Specialties Internal Medicine, Emergency Medicine, Toxicology

Written and maintained by

Dr Shashikiran Umakanth

Last revised 24 August 2026

How these tools are written and reviewed

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