Defining the role of repaglinide in the management of type 2 diabetes mellitus - A review

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia due to a combination of insulin resistance and impaired insulin secretion. The hyperglycemia is associated with an increased risk for micro- and macrovascular complications, and lowering fasting and postprandial hyperglycemia may be protective against these complications. Repaglinide is an insulin secretagogue that lowers blood glucose levels in patients with T2DM. We review the effects of repaglinide in patients with T2DM, its impact on glycemia and its non-glycemic effects, and its effects when used in special situations or patient populations. Results from randomized controlled trials, observational studies, and safety reports involving humans and published in the English-language through I May 2007 identified by a search in PubMed/MEDLINE were evaluated. Present knowledge indicates that repaglinide reduces fasting and postprandial hyperglycemia and the level of glycosylated hemoglobin (HbA(1c)) in patients with T2DM. It is at least as effective in reducing HbA(1c) and fasting plasma glucose as sulphonylureas, metformin, or the glitazones and in combination therapy with other drugs, repaglinide is as effective as any other combination. Some studies show a better effect of repaglinide on postprandial glycemia than the comparators. Its propensity to induce hypoglycemia is similar to or a little less than that of sulphonylureas. Repaglinide is associated with less weight gain than sulphonylureas and the glitazones. Repaglinide has primarily a role in the treatment of T2DM when metformin cannot be used due to adverse effects, when metformin fails to adequately control blood glucose levels, when there is a need for flexible dosing (i.e. the elderly or during Ramadan fasting), or when there is a specific wish to lower postprandial glucose. Repaglinide may also have an advantage when an oral agent is needed in diabetic patients with renal impairment. Because of its short duration of action, repaglinide should be taken before each meal, usually at least three times a day. Although no study has investigated whether repaglinide lowers total mortality or cardiovascular endpoints, several studies indicate beneficial effects on cardiovascular surrogate endpoints, such as carotid intima-media thickening, markers of inflammation, platelet activation, lipid parameters, endothelial function, adiponectin, and oxidative stress. In conclusion, repaglinide is a compound that can be used in both mono- and combination therapy for the treatment of both fasting and postprandial hyperglycemia in patients with T2DM. It can be used in patients at different stages of the disease, from uncomplicated to severe renal impairment. Although the drug has been tested in a large number of clinical trials and observational studies, its world-wide use is far less than, for example, sulphonylureas. Repaglinide may offer an additional potential for lowering blood glucose levels in T2DM that until now has not been fully realized by many clinicians.