Which of the following medications is not a sulfonylurea?

Metformin is not a sulfonylurea; it belongs to a different class of antidiabetic medications known as biguanides. Sulfonylureas, such as Glyburide, Glipizide, and Chlorpropamide, function by stimulating the pancreas to release more insulin, which helps to lower blood sugar levels in individuals with type 2 diabetes.

In contrast, Metformin works primarily by decreasing hepatic glucose production and improving insulin sensitivity, which facilitates better utilization of glucose by the cells. It helps manage blood sugar levels but does not share the same mechanism of action as sulfonylureas. This distinction is essential for understanding the pharmacological classifications and mechanisms of the medications commonly used in the treatment of diabetes.