Which of the following drug causes flaccid paralysis of ascaris?
**Core Concept**
The question is testing the student's knowledge of anthelmintic drugs and their mechanism of action. Specifically, it is asking about the drug that causes flaccid paralysis of ascaris, which is a type of nematode worm. The correct answer is a drug that acts on the muscles of the worm, causing it to relax and become paralyzed.
**Why the Correct Answer is Right**
The correct answer is Piperazine, which is a type of anthelmintic drug that works by causing flaccid paralysis of ascaris and other nematode worms. Piperazine acts by blocking the release of acetylcholine at the neuromuscular junction, which leads to relaxation of the worm's muscles and eventual paralysis. This allows the worm to be easily expelled from the body. Piperazine is a GABA agonist, which means it activates GABA receptors in the worm's nervous system, leading to a calming effect and eventual paralysis.
**Why Each Wrong Option is Incorrect**
**Option A:** Pyrantel is incorrect because it works by causing muscle contraction in the worm, rather than relaxation. It acts as a nicotinic agonist, which stimulates the worm's muscles and causes it to contract and eventually die.
**Option B:** Mebendazole is incorrect because it works by inhibiting microtubule polymerization in the worm's cells, which leads to impaired glucose uptake and eventual death. It does not cause flaccid paralysis.
**Option C:** Albendazole is incorrect because it also works by inhibiting microtubule polymerization, similar to mebendazole. It does not cause flaccid paralysis.
**Clinical Pearl / High-Yield Fact**
Piperazine is a classic example of a drug that causes flaccid paralysis, which is a distinct clinical feature that can be used to diagnose and treat nematode worm infections. Remember that piperazine works by blocking the release of acetylcholine, which is a key neurotransmitter involved in muscle contraction.
**Correct Answer:** C. Piperazine.