Type 2 diabetes is a metabolic disease that has reached epidemic proportions. The global incidence of this disease is estimated to increase from 120 million individuals to over 200 million by the year 2010. In type 2 diabetes, multiple metabolic defects contribute to hyperglycemia. These include insulin resistance, inadequate insulin secretion, and excessive hepatic glucose production. Nine classes of antihyperglycemic agents are currently approved for the treatment of type 2 diabetes (insulin, sulfonylureas, biguanides, alpha-glycosidase inhibitors, thiazolidinediones, glinides, glucagon-like peptide analogues, amylin analogues, and dipeptidyl peptidase 4 inhibitors). Each class acts by a unique mechanism on 1 or more of the metabolic defects.