Combination Tratment of Oral Agents and Insulin in Type 2 Diabetes: A Narrative Review

Abstract

Type 2 diabetes (T2DM) necessitates early and effective treatment to delay or prevent micro- and macrovascular complications associated with diabetes. Monotherapy often fails after a period of treatment, so that multiple drugs are needed to achieve effective glycemic control. It is known that insulin is very effective in reducing hyperglycemia and may improve β-cell function in patients with T2DM. Based on the improved understanding of the pathophysiology and natural history of T2DM, insulin therapy should be introduced sooner rather than later to sustain glycemic targets. Adding oral antidiabetic drugs (OAD) to insulin can improve glycemic control and potentially lower the required insulin dose, resulting in less weight gain and lower risk for hypoglycemia. The treatto-target algorithms of the recent studies combining OADs plus insulin have demonstrated that patients can reach glycemic treatment targets with low risk of hypoglycemia, greater convenience and with limited weight gain. This article presents the pharmacologic and physiologic aspects of combination treatment of oral agents with insulin in T2DM and elaborates current options available for this combination therapy. The evidence along with potential advantages and drawbacks of such regimens are discussed.