Taking a piece of metformin fasting blood sugar is normal but postprandial blood sugar is high need to be treated, you can use a combination of drugs to treat, such as the choice of non-sulfonylureas, alpha-glucosidase inhibitors and so on. 1. Non-sulfonylurea: the representative drug is Repaglinide, which is a kind of insulin secretion agent, mainly through stimulating the early phase secretion of insulin to reduce postprandial blood glucose. It is used in the treatment of type 2 diabetes. Adverse effects of Repaglinide are mainly hypoglycemia, gastrointestinal discomfort, etc. Repaglinide is contraindicated in patients with type 1 diabetes mellitus, diabetic ketoacidosis, and severe hepatic dysfunction. 2. α-glucosidase inhibitor: the representative drug acarbose, can inhibit the intestinal mucosa α-glucosidase, thereby delaying the absorption of carbohydrates, lowering postprandial glucose, can be used in combination with metformin to help patients control blood sugar. Acarbose is contraindicated in patients who are allergic to Acarbose or have severe renal insufficiency. Adverse reactions such as gastrointestinal flatulence and diarrhea may occur after taking acarbose. Therefore, patients who take one tablet of metformin with normal fasting blood glucose but high blood glucose after meals should go to the hospital in time and use the appropriate medication under the guidance of the doctor.