Medication and PharmacologyMedication Dosing and Pharmacology
Cholinergic Toxidrome
Medication-focused toxicology response with antidote use and dosing-focused treatment priorities.
Query: How do I recognize and treat a cholinergic toxidrome?
Summary
In a cholinergic toxidrome, patients typically present with signs of muscarinic excess – the classic “SLUDGE” picture (Salivation, Lacrimation, Urination, Defecation, Gastrointestinal upset, Emesis) – as well as nicotinic findings such as muscle fasciculations and weakness. Other key findings include miosis, bronchorrhea leading to respiratory compromise, and potentially seizures or altered mental status. Recognizing these findings is essential to guide prompt antidotal therapy alongside supportive care .
Agents
Dose (Atropine): 0.02 mg/kg IV bolus (start low, double the dose every 3–5 minutes until drying of secretions)
When: For patients with excessive secretions, bradycardia, or hemodynamic compromise due to muscarinic overstimulation
Monitoring: Serial cardiac monitoring and reassessment of secretions, heart rate, and blood pressure
Caution
Avoid high doses that risk atropine toxicity (e.g., tachycardia, urinary retention, hyperthermia)
In suspected organophosphate poisoning, check for nicotinic effects (i.e., muscle weakness) – atropine does not reverse these symptoms
Be cautious if the ECG shows conduction abnormalities before implementing additional therapies
Targets
Goal: Reverse life‐threatening muscarinic symptoms (e.g., bronchorrhea and bradycardia) and stabilize the patient
Hold/stop if: Secretions diminish and adverse effects (e.g., severe tachycardia) emerge
Dosing
Population
Atropine Dose
Max (per bolus)
Notes
Adult
0.02 mg/kg IV bolus; titrate by doubling dose every 3–5 minutes
Varies; often up to 2–4 mg in total
Titrate to effect – drying of secretions and improved hemodynamics
Peds
Use weight-based dosing (0.02 mg/kg IV)
Monitor cumulative dose over repeated boluses
Similar titration to adult guidelines
For organophosphate poisoning (a common cause of cholinergic toxicity), adjunct therapy with pralidoxime is indicated:
Population
Pralidoxime Dose
Max/Notes
Adult
30 mg/kg IV bolus, then infusion at 8 mg/kg/hr if needed
Addresses nicotinic effects (e.g., muscle weakness) and reactivates cholinesterase
Adjustments
Renal/Hepatic: No specific adjustments for atropine; dosing for pralidoxime is standard unless significant organ dysfunction exists
Obesity: Dose based on actual body weight may be considered, with careful titration
Benzodiazepines (e.g., midazolam 0.2 mg/kg IV) for seizure control or agitation — they do not reverse the cholinergic effects but help with supportive sedation
Supportive care measures (airway management, oxygen supplementation)