A farmer visiting an orchard gets unconscious, excessive salivation , constricted pupils and fasciculation of muscles, treatment started with
**Core Concept**
The question describes symptoms suggestive of organophosphate poisoning, a type of cholinergic toxicity. Organophosphates inhibit the enzyme acetylcholinesterase, leading to an accumulation of acetylcholine in the synaptic cleft and overstimulation of muscarinic and nicotinic receptors.
**Why the Correct Answer is Right**
The treatment of choice for organophosphate poisoning involves administering an antidote that reactivates acetylcholinesterase. Pralidoxime (2-PAM) is a specific antidote that works by reactivating the enzyme acetylcholinesterase, thereby reducing the accumulation of acetylcholine in the synaptic cleft. Atropine is often used in conjunction with pralidoxime to counteract the muscarinic effects of acetylcholine, such as excessive salivation and constricted pupils.
**Why Each Wrong Option is Incorrect**
* **Option A:** Atropine alone may be used to counteract the muscarinic effects of acetylcholine, but it does not address the underlying cause of the poisoning and would not be sufficient as a standalone treatment.
* **Option B:** Diazepam is a benzodiazepine that may be used to manage seizures or muscle fasciculations, but it is not a specific antidote for organophosphate poisoning and would not be the primary treatment.
* **Option C:** Neostigmine is an acetylcholinesterase inhibitor, which would worsen the symptoms of organophosphate poisoning by increasing the accumulation of acetylcholine in the synaptic cleft.
**Clinical Pearl / High-Yield Fact**
In cases of organophosphate poisoning, the use of atropine and pralidoxime is critical in managing the muscarinic and nicotinic effects of acetylcholine. It is essential to note that pralidoxime is most effective when administered early in the course of treatment.
**Correct Answer: D. Pralidoxime (2-PAM)**