Which antidote is indicated for organophosphate toxicity?

• A. Atropine
• B. Naloxone
• C. Flumazenil
• D. Pralidoxime

Answer: (A)

Organophosphate poisoning causes a surge of acetylcholine at both muscarinic and nicotinic receptors, leading to airway secretions, bronchospasm, slowed heart rate, pinpoint pupils, sweating, and muscle weakness. The most immediate antidote is atropine, which blocks muscarinic receptors. By doing so, it rapidly reduces the dangerous muscarinic effects—like bronchorrhea, bronchospasm, bradycardia, and excessive secretions—helping to open the airway and stabilize breathing and circulation.

Pralidoxime is another important treatment because it reactivates acetylcholinesterase, addressing both muscarinic and nicotinic symptoms more broadly and helping with muscle weakness and paralysis that atropine alone cannot reverse. In practice, atropine is used first to control life-threatening muscarinic effects, then pralidoxime is given to reverse the underlying enzyme inhibition. The other agents listed are for different types of toxicity (opioids or benzodiazepines) and do not treat organophosphate poisoning.