Anticholinergic Toxicity

Perform immediate airway, ventilation, circulation, temperature, mental-status, and point-of-care glucose assessment. Escalating agitation, coma, seizures, hyperthermia, or unstable tachyarrhythmia should be managed as severe poisoning rather than attributed solely to delirium. Anticholinergic toxicity may produce agitation, psychosis, perceptual distortion, hyperthermia, tachycardia, urinary retention, and ileus. BMJ+2BMJToxidromes and a general approach to poisoningScienceDirectAnticholinergic Syndrome - an overviewWileySevere Neurotoxicity due to Atropa belladonna Poisoning: A Case Report and Literature Review - Boskabadi - 2024 - Case Reports in Neurological Medicine - Wiley Online Library

Place the patient on cardiac monitoring and obtain a 12-lead ECG early. In suspected tricyclic antidepressant (TCA) poisoning, clinical deterioration may occur within 1 to 2 hours; sinus tachycardia may progress to wide-complex tachycardia and ventricular arrhythmias. BMJBMJTricyclic antidepressant overdose - Symptoms, diagnosis and treatment | BMJ Best Practice US A QRS duration greater than 100 ms or a rightward shift of the terminal 40-ms frontal-plane QRS vector identifies patients at greater risk for cardiac or neurologic toxicity, although ECG findings alone neither confirm nor exclude impending severe toxicity. ScienceDirectScienceDirectECG abnormalities in tricyclic antidepressant ingestion

Obtain a focused exposure history from family, emergency medical services, pharmacy records, and packaging: sedating antihistamines, antidepressants, antipsychotics, sleep aids, muscle relaxants, inhaled anticholinergics, and plant products are important medication branches. Diphenhydramine, chlorpheniramine, psychiatric medications, and jimsonweed are recognized causes. BMJ+1BMJToxidromes and a general approach to poisoningScienceDirectAnticholinergic Syndrome - an overview A shared tea, meal, or street-drug exposure with simultaneous presentations should prompt notification of poison-center and public-health partners because Datura and scopolamine adulteration have produced clusters of severe illness. CDC+2CDCAnticholinergic Poisoning Associated with an Herbal Tea -- New York City, 1994CDCJimsonweed Poisoning Associated with a Homemade Stew --- Maryland, 2008CDCScopolamine Poisoning among Heroin Users -- New York City, Newark, Philadelphia, and Baltimore, 1995 and 1996

Anticholinergic poisoning is a clinical diagnosis based on compatible exposure plus central and peripheral findings; routine clinical laboratory testing does not detect the syndrome. CDCCDCJimsonweed Poisoning Associated with a Homemade Stew --- Maryland, 2008 Delirium with dry skin and mucosa, flushing, nonreactive mydriasis, tachycardia, hypoactive or absent bowel sounds, and urinary retention is more discriminating than altered mental status alone. BMJ+3BMJToxidromes and a general approach to poisoningCDCAnticholinergic Poisoning Associated with an Herbal Tea -- New York City, 1994CDCJimsonweed Poisoning Associated with a Homemade Stew --- Maryland, 2008CDCScopolamine Poisoning among Heroin Users -- New York City, Newark, Philadelphia, and Baltimore, 1995 and 1996

Separate antimuscarinic delirium from sympathomimetic toxicity at the bedside by assessing sweating and mucosal moisture. Both syndromes can cause tachycardia, mydriasis, hyperthermia, agitation, and hypertension, but antimuscarinic poisoning is characteristically dry, whereas sympathomimetic poisoning is typically associated with diaphoresis. The absence of sweating is a key physical finding supporting anticholinergic syndrome. BMJ+1BMJToxidromes and a general approach to poisoningScienceDirectAnticholinergic Syndrome - an overview

Do not assume that a recognizable anticholinergic examination excludes TCA cardiotoxicity. TCAs combine antimuscarinic effects with sodium-channel blockade; toxidrome findings alone are insufficient to detect or exclude clinically important TCA toxicity. ScienceDirect+1ScienceDirectAnticholinergic Syndrome - an overviewScienceDirectECG abnormalities in tricyclic antidepressant ingestion The ECG therefore changes both disposition and antidote selection when a cyclic antidepressant or another sodium-channel blocker is plausible.

Use supportive treatment as the baseline strategy because most anticholinergic poisonings have a favorable outcome with vital-sign support and observation. ScienceDirectScienceDirectAnticholinergic Syndrome - an overview For agitation, benzodiazepines are part of basic treatment; they are particularly appropriate while the diagnosis remains uncertain, when seizures are present, or when physostigmine is not appropriate. ScienceDirectScienceDirectAnticholinergic Syndrome - an overview

Treat hyperthermia actively and reassess for severe central toxicity. Hyperthermia is a recognized feature of antimuscarinic poisoning, and central involvement with agitation, hallucinations, delirium, seizures, loss of consciousness, or coma signals greater severity. BMJ+1BMJToxidromes and a general approach to poisoningWileySevere Neurotoxicity due to Atropa belladonna Poisoning: A Case Report and Literature Review - Boskabadi - 2024 - Case Reports in Neurological Medicine - Wiley Online Library Patients with predominant severe central manifestations may require intensive hemodynamic monitoring. WileyWileySevere Neurotoxicity due to Atropa belladonna Poisoning: A Case Report and Literature Review - Boskabadi - 2024 - Case Reports in Neurological Medicine - Wiley Online Library

For QRS duration greater than 100 ms or wide-complex tachycardia, administer sodium bicarbonate rather than treating this as uncomplicated antimuscarinic delirium. ScienceDirectScienceDirectAnticholinergic Syndrome - an overview This ECG branch is especially important after suspected TCA ingestion because sodium-channel blockade, rather than muscarinic antagonism, drives the major conduction abnormalities. ScienceDirectScienceDirectECG abnormalities in tricyclic antidepressant ingestion

Address urinary retention directly. Acute drug-induced retention is generally managed with bladder catheterization plus discontinuation or dose reduction of the causal medication. ccjmccjmDrug-induced urinary retention: incidence, management and prevention - PubMed Anticholinergic medications, antipsychotics, antidepressants, inhaled anticholinergics, opioids, benzodiazepines, alpha-agonists, NSAIDs, calcium-channel blockers, and anesthetics can contribute; older adults are at increased risk because of comorbidity, including benign prostatic hyperplasia, and additive medication effects. ccjmccjmDrug-induced urinary retention: incidence, management and prevention - PubMed

Physostigmine is a centrally acting acetylcholinesterase inhibitor that reverses both central and peripheral antimuscarinic effects by increasing synaptic acetylcholine. BMJ+1BMJToxidromes and a general approach to poisoningScienceDirectPhysostigmine treatment of anticholinergic poisoning - ScienceDirect It is an effective, relatively safe treatment for anticholinergic delirium, but use should be selective rather than automatic because safety concerns, optimal dosing, and patient selection remain clinically important. Wiley+1WileyPharmacological management of anticholinergic deliriumWileyPharmacological management of anticholinergic delirium ‐ theory ...

Consider physostigmine when a patient has an otherwise convincing antimuscarinic syndrome with consequential agitated delirium and no ECG conduction disturbance. ScienceDirectScienceDirectAnticholinergic Syndrome - an overview The principal pre-administration decision is whether the patient could have sodium-channel blockade, particularly TCA toxicity: QRS prolongation or wide-complex rhythm should redirect treatment to sodium bicarbonate and supportive resuscitation. ScienceDirect+1ScienceDirectAnticholinergic Syndrome - an overviewScienceDirectECG abnormalities in tricyclic antidepressant ingestion

Avoid physostigmine in patients at very high risk of adverse effects. WileyWileyPharmacological management of anticholinergic delirium Historical concern has focused on cyclic antidepressant ingestion and QRS prolongation; some reviews question whether every possible cyclic-antidepressant exposure or every ECG criterion should be an absolute contraindication. ScienceDirectScienceDirectPhysostigmine treatment of anticholinergic poisoning - ScienceDirect In practice, the safer operational distinction is between a clear, ECG-normal, predominantly antimuscarinic delirium and a possible mixed overdose with conduction abnormality, where the competing cardiotoxicity must take priority. ScienceDirect+2ScienceDirectAnticholinergic Syndrome - an overviewScienceDirectECG abnormalities in tricyclic antidepressant ingestionWileyPharmacological management of anticholinergic delirium

Physostigmine can produce rapid reversal in observed outbreaks and case series, but its duration may be shorter than the poisoning syndrome. CDC+1CDCAnticholinergic Poisoning Associated with an Herbal Tea -- New York City, 1994WileyCase series profile of olanzapine post‐injection delirium/sedation ... Reassess mental status, pulse, blood pressure, and ECG after reversal; recurrent delirium requires renewed evaluation for ongoing absorption, co-ingestion, or a longer-acting agent rather than assuming diagnostic closure.

Continue observation with serial clinical and ECG assessment when TCA exposure is possible because significant cardiovascular and neurologic deterioration can occur early and ECG abnormalities may emerge during emergency-department evaluation. BMJ+1BMJTricyclic antidepressant overdose - Symptoms, diagnosis and treatment | BMJ Best Practice USScienceDirectECG abnormalities in tricyclic antidepressant ingestion ICU-level monitoring is appropriate for patients with severe central manifestations or hemodynamic instability. WileyWileySevere Neurotoxicity due to Atropa belladonna Poisoning: A Case Report and Literature Review - Boskabadi - 2024 - Case Reports in Neurological Medicine - Wiley Online Library

Before discharge after a medication-related event, reconcile all agents that impair bladder emptying or add anticholinergic burden. Acute urinary retention is associated with antipsychotics, antidepressants, anticholinergic respiratory medications, opioids, benzodiazepines, alpha-agonists, NSAIDs, detrusor relaxants, calcium-channel blockers, and anesthetics; medication combinations can amplify risk. ccjmccjmDrug-induced urinary retention: incidence, management and prevention - PubMed

For plant, food, tea, or illicit-drug clusters, document the suspected source and alert poison-center and public-health channels. Datura-related outbreaks have followed herbal tea and homemade food, while scopolamine-adulterated heroin has produced regional clusters; recognition protects co-exposed persons who may still be symptomatic or deteriorate. CDC+2CDCAnticholinergic Poisoning Associated with an Herbal Tea -- New York City, 1994CDCJimsonweed Poisoning Associated with a Homemade Stew --- Maryland, 2008CDCScopolamine Poisoning among Heroin Users -- New York City, Newark, Philadelphia, and Baltimore, 1995 and 1996