Which of the following medications is a Biguanide?

The medication classified as a Biguanide is Metformin. This drug is widely used in the management of type 2 diabetes mellitus due to its ability to improve insulin sensitivity and decrease hepatic glucose production. Biguanides, as a class, primarily function by reducing the amount of glucose produced by the liver and enhancing the uptake of glucose by peripheral tissues, which helps to lower blood sugar levels effectively.

The other medications listed belong to different classes; for example, Pioglitazone is a thiazolidinedione that primarily works by increasing insulin sensitivity, Glimepiride is a sulfonylurea that stimulates insulin secretion from the pancreas, and Saxagliptin is a DPP-4 inhibitor that increases incretin levels, leading to increased insulin release and decreased glucagon levels. Understanding these distinctions is important for comprehending how diabetes medications work and their role in management strategies.