Management of Anticholinergic Toxicity

Clinical Presentation

The American Academy of Pediatrics notes that anticholinergic toxicity presents with central nervous system effects, including agitated delirium, hallucinations, seizures, and coma, as well as cardiovascular effects such as tachycardia and mild hypertension, in patients with anticholinergic toxicity 1, 2
Anticholinergic toxicity also presents with respiratory effects, including tachypnea, and skin effects, including hot, dry, erythematous skin, in patients with anticholinergic toxicity 1, 2
The American Academy of Pediatrics reports that anticholinergic toxicity can cause eye effects, including mydriasis (dilated pupils), and gastrointestinal effects, including hypoactive or absent bowel sounds, in patients with anticholinergic toxicity 1, 2
Other effects of anticholinergic toxicity include hyperthermia and urinary retention, according to the American Academy of Pediatrics 2, 3

The American Heart Association recommends securing airway, breathing, and circulation in patients with anticholinergic toxicity 3
The American Academy of Pediatrics suggests obtaining vital signs, including temperature, heart rate, and blood pressure, in patients with anticholinergic toxicity 1
A focused neurological assessment should be performed to evaluate level of consciousness and presence of agitation in patients with anticholinergic toxicity, according to the American Academy of Pediatrics 2
The American College of Cardiology recommends obtaining an ECG to assess for QRS prolongation or dysrhythmias in patients with anticholinergic toxicity 4

The American Academy of Pediatrics recommends discontinuing the precipitating anticholinergic agent in patients with anticholinergic toxicity 1
Supportive care, including IV fluids for hydration, should be provided to patients with anticholinergic toxicity, according to the American Academy of Pediatrics 1
Benzodiazepines should be administered for agitation and seizure control in patients with anticholinergic toxicity, as recommended by the American Academy of Pediatrics 1, 2
Activated charcoal may be considered if recent oral ingestion and airway is protected in patients with anticholinergic toxicity, according to the American Academy of Pediatrics 3

Physostigmine is indicated for severe anticholinergic toxicity with significant central nervous system effects or life-threatening peripheral manifestations, according to the American Academy of Clinical Toxicology 3
Adult dosing of physostigmine is 1-2 mg IV slowly over 5 minutes, which may be repeated after 10-30 minutes if needed, as recommended by the American Academy of Clinical Toxicology 3
Pediatric dosing of physostigmine is 0.02 mg/kg IV (maximum 0.5 mg/dose), according to the American Academy of Pediatrics 3

Hyperthermia should be treated with external cooling measures in patients with anticholinergic toxicity, as recommended by the American Academy of Pediatrics 1
Urinary retention may be treated with bladder catheterization in patients with anticholinergic toxicity, according to the American Urological Association 3
Prolonged QRS or dysrhythmias may be treated with sodium bicarbonate administration in patients with anticholinergic toxicity, as recommended by the American Heart Association 1
Severe agitation not responsive to benzodiazepines may be treated with physostigmine in patients with anticholinergic toxicity, according to the American Academy of Clinical Toxicology 3

Patients receiving physostigmine have significantly lower rates of intubation compared to those receiving other treatments, according to the American Academy of Clinical Toxicology 3
Avoid succinylcholine in patients with anticholinergic crisis as it may cause prolonged paralysis, as recommended by the American Society of Anesthesiologists 3

Continuous cardiac monitoring should be performed for at least 6 hours after symptom resolution in patients with anticholinergic toxicity, as recommended by the American Heart Association 3
Serial neurological assessments should be performed to evaluate response to treatment in patients with anticholinergic toxicity, according to the American Academy of Neurology 3

Physostigmine is contraindicated in patients with cardiovascular disease, asthma, gangrene, diabetes, or mechanical obstruction of the intestines or urinary tract, as recommended by the American Academy of Clinical Toxicology 3
Underdosing of physostigmine is common, and larger doses than standard may be required in severe cases, according to the American Academy of Clinical Toxicology 3

Elderly patients are more susceptible to anticholinergic toxicity due to baseline decreased acetylcholine physiology, with common culprits including diphenhydramine, cyclobenzaprine, and oxybutynin, and a lower threshold for physostigmine administration is recommended due to the higher risk of falls and delirium complications, as suggested by the Mayo Clinic Proceedings 5

Airway, breathing, and circulation take absolute priority over toxin identification, and supportive care should not be delayed while attempting to identify the specific toxin. 6, 7
Remove any remaining plant material from the patient as part of exposure discontinuation. 6
Do not induce vomiting because of the risk of aspiration and rapid deterioration of mental status. 6

Vital signs in anticholinergic poisoning commonly show mild hyperthermia (≤ 38.8 °C), tachycardia, mild hypertension, and tachypnea. 8
Central nervous system effects frequently include agitated delirium, hallucinations, disorientation, incomprehensible speech, seizures, or coma. 8
Cardiovascular manifestations are characterized by tachycardia and mild hypertension. 8
Dermatologic signs consist of hot, dry, erythematous, flushed skin with absent sweating. 8
Ocular findings feature markedly dilated, sluggish or fixed pupils (mydriasis). 8
Gastrointestinal findings may involve hypoactive or absent bowel sounds and dry mucous membranes. 8
Respiratory findings can include tachypnea and reduced pharyngeal and bronchial secretions. 8

Contact a regional poison‑control center or medical toxicologist for expert guidance, especially when considering physostigmine administration. 6