Doctors often prescribe drugs to help patients with type 2 diabetes control their blood sugar. They use a blood test (called hemoglobin A1c) to assess sugar control. In most cases, doctors should aim for optimal control of sugar levels (hemoglobin A1c values less than 7%), depending on several factors. Some patients need more than 1 drug to get their blood sugar levels under optimal control. Drugs that may be used include insulin, alpha-glucosidase inhibitors (acarbose and miglitol), biguanides (metformin), sulfonyureas (glipizide or glyburide), and thiazolidinediones (TZDs, such as rosiglitazone and pioglitazone). Exenatide is a new drug called an incretin mimetic. Few studies have assessed whether adding this drug to TZD treatment improves sugar control.