The antidiabetic drug market is characterized by steady increases in volume, and newly approved drugs experienced substantial uptake, especially DPP-4 inhibitors. The use of rosiglitazone has been negligible since restrictions were put in place in 2011. Further study is needed to understand why one-third to one-half of other noninsulin antidiabetic drug use was not concomitant with metformin use despite guidelines recommending that metformin be continued when other agents are added to treatment (Diabetes Care)