Question

All of the following antidiabetic drugs act by enhancing insulin secretion except

• A. Exenatide
• B. Alogliptin
• C. Glibenclamide
• D. Rosiglitazone

Hint:

Antidiabetic drugs lower blood glucose by different routes — some increase insulin release (secretagogues/incretin-based), while others improve insulin sensitivity.

Answer 1

The Correct Option is D

Step 1: The question format - all EXCEPT.
This is a negative question. We need to find the drug that does NOT enhance insulin secretion. Three drugs do enhance it; one does not.

Step 2: Evaluate Option 1 - Exenatide.
Exenatide is a GLP-1 receptor agonist. GLP-1 stimulates glucose-dependent insulin secretion from pancreatic beta-cells. So Exenatide DOES enhance insulin secretion.

Step 3: Evaluate Option 2 - Alogliptin.
Alogliptin is a DPP-4 inhibitor. It prevents breakdown of GLP-1, which in turn enhances insulin secretion in a glucose-dependent manner. So Alogliptin DOES enhance insulin secretion.

Step 4: Evaluate Option 3 - Glibenclamide.
Glibenclamide is a sulfonylurea that acts on ATP-sensitive K⁺ channels on beta-cells, closing them and causing depolarization, which leads to insulin release. So Glibenclamide DOES enhance insulin secretion.

Step 5: Evaluate Option 4 - Rosiglitazone.
Rosiglitazone is a thiazolidinedione (TZD). It acts as a PPAR-gamma agonist and reduces insulin resistance in peripheral tissues (fat, muscle, liver). It does NOT stimulate insulin secretion. It works by making the body more sensitive to the insulin already present.

Step 6: Conclusion.
Rosiglitazone is the only drug among the choices that does not enhance insulin secretion.
Answer: Option (4) — Rosiglitazone