From the Research
The recommended atropine dosing for organophosphate (OP) poisoning begins with 1-2 mg IV bolus for adults, which should be doubled every 5 minutes until signs of atropinization appear (dry mucous membranes, decreased bronchial secretions, mydriasis, tachycardia) 1. In severe cases, doses may need to escalate rapidly, sometimes requiring 10-20 mg or more in the first hour. After achieving atropinization, continuous infusion at 10-20% of the total loading dose per hour is typically maintained. For children, the initial dose is 0.02-0.05 mg/kg, doubled every 5 minutes until atropinization. Some key points to consider when treating OP poisoning include:
- Treatment should continue for at least 24 hours after symptoms resolve, with gradual tapering to avoid recurrence of cholinergic symptoms.
- Atropine works by competitively blocking muscarinic acetylcholine receptors, counteracting the excess acetylcholine that accumulates due to the organophosphate's inhibition of acetylcholinesterase.
- This addresses the muscarinic symptoms (bronchorrhea, bronchospasm, bradycardia, hypotension) but does not treat nicotinic effects like muscle weakness, which require additional interventions such as pralidoxime.
- High-dose atropine therapy and early intervention are crucial in managing OP poisoning, and novel treatment approaches such as hemofiltration treatments and lipid solutions have been studied in recent years 1.
- Grading the severity of OP poisoning is essential to identify high-risk cases, and a revised simplified grading is proposed 2.
- Cardiac monitoring of OP intoxicated patients for relatively long periods after the poisoning and early aggressive treatment of arrhythmias may be the clue to better survival 3.