INS and type 2 diabetes mellitus: A variety of drugs are used to treat T2DM and can be divided into five main categories: drugs that stimulate insulin production by beta cells (sulfonylureas), improve insulin action (thiazolidinediones), delay carbohydrate uptake in the gut (alpha-glucosidase inhibitors), reduce hepatic glucose production (metformin) or target the glucagon-like peptide (GLP-1) axis (GLP-1 receptor agonists or DPP-4 inhibitors) (9).