Question

Which of the following drugs irreversibly inhibits the \(H^+/K^+\)-ATPase pump in gastric parietal cells used to treat peptic ulcer disease?

• A. Misoprostol
• B. Ranitidine
• C. Sucralfate
• D. Omeprazole

Hint:

Omeprazole is a proton pump inhibitor and blocks the final step of gastric acid secretion.

Answer 1

The Correct Option is D

Concept:
Peptic ulcer disease is commonly treated by reducing gastric acid secretion. Proton pump inhibitors are among the most effective acid-suppressing drugs.

Step 1: Understanding the proton pump.
The \(H^+/K^+\)-ATPase pump is present in gastric parietal cells. It is responsible for the final step of acid secretion into the stomach.

Step 2: Role of omeprazole.
Omeprazole is a proton pump inhibitor. It irreversibly inhibits the \(H^+/K^+\)-ATPase pump. \[ H^+/K^+\text{-ATPase inhibition} \Rightarrow \text{decreased gastric acid secretion} \]

Step 3: Why irreversible inhibition is important.
Because omeprazole irreversibly blocks the pump, acid secretion remains reduced until new proton pumps are synthesized.

Step 4: Checking other options.
Misoprostol is a prostaglandin analogue.
Ranitidine is an \(H_2\)-receptor blocker.
Sucralfate forms a protective coating over ulcerated mucosa.
Omeprazole directly inhibits the proton pump.

Step 5: Final answer.
Therefore, the drug that irreversibly inhibits the \(H^+/K^+\)-ATPase pump is omeprazole. \[ \boxed{\text{Omeprazole}} \]