Question

Match List-I with List-II 
 
Choose the correct answer from the options given below:} 
 

• (A) - (II), (B) - (III), (C) - (IV), (D) - (I)
• (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)

Hint:

To remember these key gastrointestinal drug classes:
- Ondansetron is a setron, which are selective \(\text{5-HT}_3\) blockers used for severe vomiting.
- Ranitidine is a tidine, which are \(\text{H}_2\) antihistamines used for ulcers.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Autonomic and gastrointestinal drugs act by binding to specific neurotransmitter or hormone receptors, serving as agonists or antagonists to modulate physiological functions.

Step 2: Detailed Explanation:
Let us match each drug with its specific target receptor:
- (A) Ranitidine: This is a competitive antagonist of the histamine \(\text{H}_2\)-receptor (III) on gastric parietal cells.
It is used to decrease gastric acid secretion and manage ulcers. Thus, (A) matches with (III).
- (B) Ondansetron: This is a selective \(\text{5-HT}_3\) receptor antagonist (IV).
It is used as an antiemetic to control severe vomiting by acting on serotonin receptors in the chemoreceptor trigger zone (CRTZ) and vagal afferents. Thus, (B) matches with (IV).
- (C) Metoclopramide: This is a prokinetic and antiemetic agent that acts as a central and peripheral dopamine \(\text{D}_2\)-receptor antagonist (I). Thus, (C) matches with (I).
- (D) Pirenzepine (Pienzepine): This is a selective muscarinic \(\text{M}_1\)-receptor antagonist (II).
It is used to reduce gastric acid secretion by blocking acetylcholine signaling. Thus, (D) matches with (II).
This matching sequence gives: (A) - (III), (B) - (IV), (C) - (I), (D) - (II).

Step 3: Final Answer:
The correct match is (A) - (III), (B) - (IV), (C) - (I), (D) - (II). This corresponds to option (C).