<p>This tablet combines two antihyperglycemic agents with complementary mechanisms of action to improve glycemic control in patients with type 2 diabetes. Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, and Metformin HCl, a member of the biguanide class. Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor, which is believed to exert its actions in patients with type 2 diabetes by slowing the inactivation of incretin hormones. Incretin hormones, including glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are released by the intestine throughout the day, and levels are increased in response to a meal. These hormones are rapidly inactivated by the enzyme, DPP-4. The incretins are part of an endogenous system involved in the physiologic regulation of glucose homeostasis. When blood glucose concentrations are normal or elevated then GLP-1 and GIP increase insulin synthesis and release from pancreatic beta cells by intracellular signaling pathways involving cyclic AMP. GLP-1 also lowers glucagon secretion from pancreatic alpha cells, leading to reduced hepatic glucose production. By increasing and prolonging active incretin levels, Sitagliptin increases insulin release and decreases glucagon levels in the circulation in a glucose-dependent manner. The pharmacologic mechanism of action of Metformin HCl is different from other classes of oral antihyperglycemic agents. Metformin HCl decreases hepatic glucose production, decreases intestinal absorption of glucose and increases peripheral glucose uptake and utilization.</p>