Acarbose is the first of a new class of antidiabetic agents, the alpha-glucosidase inhibitors. Acarbose has proven effectiveness as a first-line drug in type 2 diabetes insufficiently controlled by diet alone. In addition to providing short-term glycemic control, acarbose also reduces HbA1c levels. This effect is greatest when therapy is initiated early in the disease and when baseline HbA1c levels are high. Depending on the baseline HbA1c value, therapeutic doses of acarbose lead to a HbA1c reduction of 0.5%-1.2%. Acarbose may be safely combined with all oral hypoglycemic agents, and has been found to have utility as an adjunct to sulfonylurea and metformin therapy. It also improves control of insulin-treated type 2 diabetes and enables a reduction of exogenous insulin requirements of up to 30%. Acarbose also has beneficial effects on the coronary risk factors, e.g. postprandial triglyceride levels, elevated cholesterol, and hyperinsulinemia. The early phase of acarbose therapy may be associated with side effects such as meteorism, flatulence, and diarrhea. These result from the local effect of the drug and decline with time. To date, there have been no reports of systemic toxicity. Acarbose does not cause hypoglycemias or weight gain.