TREATMENT OF DIABETES MELLITUS 2 THROUGH METFORMIN

Role of Metformin in Treatment of Type 2 Diabetes Mellitus

Role of Metformin in Treatment of Type 2 Diabetes Mellitus

Introduction

Type 2 diabetes mellitus results from impaired insulin secretion and reduced peripheral insulin sensitivity. Treatment options include diet, oral antihyperglycemic agents, and insulin. Metformin, an oral biguanide, ameliorates hyperglycemia by improving peripheral sensitivity to insulin, and reducing gastrointestinal glucose absorption and hepatic glucose production. Unlike sulfonylureas, it does not stimulate insulin secretion, aggravate hyperinsulinemia, or cause hypoglycemia or weight gain (weight stabilizes or decreases). It also has beneficial effects on serum lipid profiles. In lean or overweight type 2 diabetic patients uncontrolled by diet, metformin monotherapy significantly improves glycemic control, compared with placebo, and to similar extents as sulfonylurea monotherapy. (Poulsen & Nielsen 2005 3273-3279) In secondary sulfonylurea failure, combination metformin-sulfonylurea treatment significantly improves glycemic control beyond that achieved with either agent alone. Metformin-sulfonylurea also appears to be as effective as insulin or insulin plus sulfonylurea, suggesting that such combination therapy may obviate or substantially delay insulin therapy.

Critical Evaluation of the Role of Metformin in Treatment of Type 2 Diabetes Mellitus

Although dietary management is the mainstay of therapy, at least 50% of type 2 diabetic patients require the addition of an oral antihyperglycemic agent to achieve satisfactory glycemic control. In the United States, the number of type 2 diabetic patients estimated to be on treatment with insulin is about 30%, and many of these patients first underwent therapy with oral sulfonylurea agents. At present, sulfonylureas are more commonly prescribed worldwide than metformin but can promote weight gain (as patients are brought under control) and cause hypoglycemia. Metformin is not associated with weight gain, does not produce hypoglycemia, and can also have a favorable effect on the dyslipidemia of type 2 diabetes mellitus (Ovalle & Bell 2006 146-147)

Metformin monotherapy is considered to be a first-line treatment in patients prone to weight gain and/or are dyslipidemic and who have failed to achieve adequate glycemic control on dietary management alone. Metformin is also used, however, in combination with other antihyperglycemic agents and insulin. Patients with type 2 diabetes mellitus uncontrolled by dietary management and a sulfonylurea may have metformin added to their treatment regimen. Such combination treatment has been reported to provide satisfactory long-term glycemic control. This approach has been questioned in the literature because the eventual need for insulin is unavoidable in one third of patients who develop diabetes after the age of 40 years. However, the use of combination therapy may obviate the need for insulin injections in some patients or at least delay the need for insulin for several years. (Moses et al., 2008 119-124)

Metformin is an antihyperglycemic agent which improves glucose tolerance in type 2 diabetic patients, lowering both basal and postprandial plasma glucose levels. Its mode of action differs from that of the sulfonylureas and, in contrast to the latter agents, metformin alone does not produce hypoglycemia in either diabetic or nondiabetic individuals. Pharmacological studies indicate that metformin acts by (a) improving peripheral sensitivity to ...