Anticholinergic syndrome follows exposure to substances that are muscarinic receptor antagonists. Clinical effects include tachycardia, delirium, hallucinations, mydriasis, dry skin and mucous membranes, urinary retention, decreased gastric motility, and occasionally hyperthermia.
Implicated medications include anticholinergics such as atropine, benztropine, and scopolamine; antihistamines such as diphenhydramine; antipsychotics such as clozapine and quetiapine, antispasmodics such as dicyclomine and oxybutynin; tricyclic antidepressants such as amitriptyline and imipramine; and muscle relaxants such as cyclobenzaprine.
Some plants such as Jimson weed (Datura stramonium) and deadly nightshade, also known as belladonna (Atropa belladonna), have anticholinergic properties.
Related topic: poisoning caused by sedative
Potentially life-threatening emergency
Anticholinergic syndrome
Alerts and Notices
Synopsis
Codes
ICD10CM:
T44.3X1A – Poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, accidental (unintentional), initial encounter
SNOMEDCT:
216593002 – Accidental poisoning by anticholinergic
T44.3X1A – Poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, accidental (unintentional), initial encounter
SNOMEDCT:
216593002 – Accidental poisoning by anticholinergic
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Neuroleptic malignant syndrome
- Serotonin syndrome
- Sympathomimetic syndrome
- Malignant hyperthermia
- Alcohol withdrawal
- Benzodiazepine withdrawal
- Hypoglycemia
- Central nervous system infection (meningitis [viral, bacterial, fungal], encephalitis)
- Autoimmune encephalitis
- Head trauma (see, eg, traumatic brain injury)
- Pheochromocytoma
- Thyrotoxicosis
- Heat stroke
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
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References
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Last Reviewed:09/04/2022
Last Updated:07/06/2023
Last Updated:07/06/2023
Potentially life-threatening emergency
Anticholinergic syndrome