Now that you have some good advice on the insulins here's some info on oral antidiabetics:
(Acarbose, Miglitol) act locally in GI tract to inhibit Alpha-glucosidase which is responsible for carb breakdown, because of it's mechanism of action it does not cause hypoglycemia.
(Metformin) works by multiple mechanisms. It reduces gluconeogenesis, decreases intestinal reabsorption of glucose, increases cellular uptake of glucose, and increases excretion of glucose. It also does not cause hypoglycemia.
(Sitagliptan/Januvia) Inhibits DPP-4 from breaking down incretins, increased levels of incretins lowers blood glucose because incretins respond to glucose load and are responsible for 60% of insulin release. These can cause hypoglycemia.
(Prandin) Stimulate insulin release from pancreatic beta-cells. These can cause hypoglycemia.
(Glyburide, Glipizide) stimulate release of insulin from pancreatic beta cells and increase sensitivity of peripheral tissues to insulin. These can cause hypoglycemia.
*Thiazolidinedione aka TZDs
(Avandia, Actose) increase cellular sensitivity to insulin and decrease gluconeogenesis by liver. These can cause hypoglycemia.
*Antihypoglycemic Agent (
Glucogon/Gluca Gen) increases glycogenolysis, stimulates uptake of amino acids, increases gluconeogenesis, and promotes lipolysis.
You can find all of this in your drug book and much more information, but this should provide a brief overview. I pulled this information from Davis's Drug Guide and my teachers. Hope it helps.