Metformin: A Review of Its Use in the Treatment of Type 2 Diabetes

Metformin is now the most widely prescribed oral hypoglycemic agent. This review outlines its use in the treatment of type 2 diabetes. The main mechanisms of action include reduction of appetite and of intestinal carbohydrate absorption, inhibition of hepatic gluconeogenesis, and increased glucose uptake by peripheral tissues. Metformin has been established as the drug of choice for the first-line treatment of type 2 diabetes. According to broadly accepted guidelines, it should be administered early at diagnosis of this metabolic disorder, alongside diet and exercise. This agent may also be safely and efficaciously combined with all other oral hypoglycemic agents, enabling a useful additive effect. Additionally, it may be prescribed in conjunction with insulin. This combination aims to offset insulin resistance, reduce insulin requirements and minimize weight gain. Of greater importance, metformin has been consistently shown to have a favorable effect on cardiovascular risk factors and to improve cardiovascular outcomes. Interestingly, the efficacy of metformin is accompanied by excellent safety: caution is only needed to avoid the drug in patients with obvious contraindications (mainly chronic renal failure, congestive heart failure, chronic obstructive pulmonary disease, liver disease). Moreover, the cost-effectiveness of metformin has been established. Generally, metformin is an excellent choice both in the specialized setting and in primary health care.