Treatment of Cholinergic Intoxication

Protocol for Initial Treatment

The American Heart Association recommends atropine as the first-line medication for cholinergic intoxication, to be administered immediately in doses of 1-2 mg IV for adults (0.02 mg/kg for children), doubling the dose every 5 minutes until complete atropinization is achieved, always in conjunction with pralidoxime and benzodiazepines 1, 2
Remove contaminated clothing and perform copious irrigation with water and soap for dermal exposure 1
Use personal protective equipment (PPE) when handling contaminated patients to prevent secondary intoxication of healthcare professionals 1

Initial dose for adults: 1-2 mg IV 1, 2
Initial dose for children: 0.02 mg/kg IV (minimum 0.1 mg, maximum single dose 0.5 mg) 1, 2
Double the dose every 5 minutes until atropinization is complete 1, 2
Never stop escalating the dose due to tachycardia - tachycardia is not a contraindication for continuing atropine administration 1
Cumulative doses can reach 10-20 mg in the first 2-3 hours, with some patients requiring up to 50 mg in 24 hours 2

The American Heart Association recommends pralidoxime with evidence Class 2a, Level A 1
Pralidoxime should be administered early in conjunction with atropine, as it reverses the nicotinic effects that atropine cannot reverse 1
Initial IV dose for adults: 1-2 g, preferably as an infusion in 100 mL of saline solution over 15-30 minutes 1

Administer benzodiazepines (diazepam or midazolam) to treat seizures and agitation 1, 2, 3
Benzodiazepines are essential for controlling CNS effects 3

Early endotracheal intubation is recommended for life-threatening intoxication 1
Observational data suggest better outcomes with early intubation in significant organophosphate poisoning 1
Avoid neuromuscular blockers metabolized by cholinesterase (succinylcholine and mivacurium) - they are not recommended for patients with organophosphate poisoning 1

Organophosphate poisoning causes a biphasic pattern of cardiac effects 4
Phase 1 (minutes): brief period of cardiac hyperstimulation with hypertension and sinus tachycardia due to nicotinic stimulation 4
Phase 2 (hours): severe cardiac depression manifested as bradycardia and hypotension due to parasympathetic hyperstimulation of muscarinic receptors 4
Alterations in ST-T segments may appear, as well as atrioventricular conduction disturbances 4, 3
Prolongation of the QTc interval on the ECG denotes a poor prognosis 4

Never underestimate the necessary doses - organophosphate poisoning often requires high total doses of atropine 2
The therapeutic goal is control of muscarinic symptoms, not normalization of heart rate 2
In children, relatively higher doses are necessary compared to standard pediatric resuscitation doses 1

Severe myonecrosis can result from excessive accumulation of acetylcholine causing calcium influx into skeletal muscle 1
Rhabdomyolysis with subsequent myoglobinuria can cause renal damage 1
Monitor creatine kinase and potassium levels 1
Treatment of rhabdomyolysis: adequate hydration, forced diuresis, and urine alkalization when urine turns reddish (due to myoglobin, not hemoglobin) 1
Monitor for late-onset muscle weakness, which can follow the initial cholinergic crisis up to 4 days after acute exposure 1
Restoration of normal enzyme activity can take up to 6 weeks in untreated patients 2
Maintain monitoring for at least 48-72 hours 1