- Known history of hypersensitivity to metformin (e.g. Glucophage®) and/or related drugs such as glyburide (Diaβeta®, Euglucon®), tolbutamide (Orinase®, Apo-chlorpropamide), acetohexamide (Dimelor®), chlorpropamide (Diabinese®) and glipizide (Glucotrol®, Glibenese®).