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Anticholinergic Agents (Anticholinergic Toxidrome)

Concise toxidrome definition: Exposure to an anticholinergic chemical may result in under stimulation of cholinergic receptors leading to dilated pupils (mydriasis), decreased sweating, elevated temperature, rapid heart beat, and mental-status changes, including characteristic hallucinations.

Rationale or reasoning for toxidrome decisions: The name was chosen based upon clinical relevance and accuracy as well as ease of recall. Examples of names initially considered included: Anticholinergics, (BZ)/hallucinations, delirium, dry all over, hot.

Issues or concerns about this toxidrome:  Recognition by providers of the characteristic nature of anticholinergic hallucinations and other CNS effects; recognition of CNS vs. ANS (peripheral) signs and symptoms; training will need to address possible confusion between “cholinergic,” “anticholinergic,” and “anticholinesterase.”

Anticholinergic examples of industrial chemicals and potential chemical warfare/terrorism agents: BZ (3-quinuclidinyl benzilate), and other glycolate anticholinergics (tropane alkaloids) [atropine, hyoscyamine, scopolamine].

The clinically relevant routes of exposure and types of sources: Inhalation, ingestion, and dermal.

The organ systems generally affected: Central nervous system (CNS), and Autonomic Nervous System (ANS, parasympathetic portion).

The initial signs and symptoms: Blind as a bat, dry as a bone, full as a flask (can’t urinate), hot as a hare (or hell, or Hades), red as a beet, mad as a hatter (concrete, easily describable, often Lilliputian hallucinations), tacky (tachycardic) as a leisure suit (pink flamingo); phantom behaviors (“woolgathering”).

A progression of signs and symptoms includes: Initial peripheral parasympathetic signs and symptoms (“blind as a bat, . . .”); then confusion with hallucinations and agitated delirium; eventually stupor and coma; finally recovery of consciousness with paranoia.

The underlying pathology, biological processes, or modes of action include: Competitive antagonism of cholinergic receptors peripherally and in the CNS. 

Common treatment protocol, specific antidotes and key supportive measures: Physostigmine, cooling, benzodiazepines, general supportive care. 

Report to the Toxic Chemical Syndrome Definitions and Nomenclature Workshop (PDF - 2.01 MB) (DHS, NLM, May, 2012)

Information from Other Resources

Resource Comparison Table of Resource Comparison
Information from CDC, WISER, and CAMEO
Emergency Response Safety and Health Database (CDC/NIOSH) arrow WISER (NIH/NLM) arrow
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Medical Management Guidelines for Acute Chemical Exposures (CDC/ATSDR) arrow
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Chemical Emergencies (CDC) arrow

Additional Resources:

ChemIDplus - Chemical dictionary, structures, and links to many Internet resources (NIH/NLM)
BZ (3-quinuclidinyl benzilate), Other glycolate anticholinergics (tropane alkaloids) [Atropine, Hyoscyamine, Scopolamine]

Hazardous Substances Data Bank - Comprehensive, peer-reviewed toxicology data (NIH/NLM)
BZ (3-quinuclidinyl benzilate), Other glycolate anticholinergics (tropane alkaloids) [Atropine, Hyoscyamine, Scopolamine]

Report on Toxic Chemical Syndromes: Definitions and Nomenclature (PDF - 2.01 MB)

An Interagency Agreement between the Department of Homeland Security (DHS) Office of Health Affairs (OHA) and the National Library of Medicine led to a workshop to discuss and develop a consistent lexicon to describe toxic chemical syndromes, or toxidromes. This workshop included practitioners and experts in emergency response, emergency medicine, and medical toxicology developed names and definitions for twelve unique toxidromes that describe and differentiate the clinical signs and symptoms from exposures to chemicals. These toxidromes focus on acute signs and symptoms caused by inhalation and dermal exposures, and each toxidrome is characterized by exposure routes and sources, organs/systems affected, initial signs and symptoms, underlying mode of action, and treatment/antidotes. The toxidrome names and definitions are designed to be readily understood and remembered by users since communication in a crisis requires accurate and succinct terms that can quickly convey the health conditions of patients. These toxidromes lay the foundation for a consistent lexicon for use in CHEMM and for other uses that, if adopted widely, will improve response to chemical mass exposure incidents.

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