True statement about pralidoxime is:
## Core Concept
Pralidoxime is a medication used to treat organophosphate poisoning. It works by reactivating acetylcholinesterase, the enzyme inhibited by organophosphates. This process is crucial in managing acute poisoning.
## Why the Correct Answer is Right
The correct statement about pralidoxime is that it acts by reactivating acetylcholinesterase. Organophosphates irreversibly inhibit acetylcholinesterase, leading to an accumulation of acetylcholine in the synaptic cleft and causing overstimulation of muscarinic and nicotinic receptors. Pralidoxime works by binding to the phosphorus atom of the inhibited enzyme, allowing for the restoration of its activity.
## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because pralidoxime does not primarily work by competing with acetylcholine for receptor sites; its action is more specific to reactivating acetylcholinesterase.
- **Option B:** This option is incorrect as pralidoxime's effectiveness is not mainly due to its antimuscarinic properties; it directly addresses the enzyme inhibition caused by organophosphates.
- **Option C:** This option might seem plausible but is incorrect because while pralidoxime does have a role in treating organophosphate poisoning, the statement is not provided to assess its accuracy directly.
## Clinical Pearl / High-Yield Fact
A key point to remember is that pralidoxime is most effective when used early in the course of organophosphate poisoning. It has limited ability to cross the blood-brain barrier, making it less effective against central nervous system effects of poisoning.
## Correct Answer: D.