Glyburide belongs to which drug class?

• A. Biguanide
• B. Sulfonylurea
• C. Thiazolidinedione
• D. DPP-4 inhibitor

Answer: (B)

Glyburide is a sulfonylurea, a class that increases the body's own insulin production. It acts on pancreatic beta cells by binding to the sulfonylurea receptor on the ATP-sensitive potassium (KATP) channel. This closes the channel, the cell depolarizes, calcium channels open, and insulin granules are released. This mechanism relies on some remaining beta-cell function, which is why sulfonylureas are used in type 2 diabetes with preserved insulin secretion. A practical point is the risk of hypoglycemia, particularly in the elderly or if meals are skipped. Other drug classes differ in action: metformin (a biguanide) lowers hepatic glucose production and improves insulin sensitivity without stimulating insulin release; thiazolidinediones (PPAR gamma agonists) mainly improve insulin sensitivity; DPP-4 inhibitors increase incretin hormones to boost glucose-dependent insulin secretion and typically carry a lower hypoglycemia risk.