Rosiglitazone maleate/metformin hydrochloride: a new formulation therapy for type 2 diabetes

Many patients with type 2 diabetes require treatment with more than one antihyperglycemic drug to achieve optimal glycemic control. The thiazolidinediones are a novel class of oral antihyperglycemic drugs that improve glycemic control primarily by increasing peripheral insulin resistance and sensitizing the skeletal muscle, liver and adipose tissue to the actions of insulin, in addition to improving beta-cell function. One of the many features of the thiazolidinedione class of drugs is their synergism with other antihyperglycemic drugs that have a different mechanism of action. The combination of metformin hydrochloride, a biguanide that enhances glucose uptake in peripheral tissues and reduces hepatic gluconeogenesis, with rosiglitazone maleate, one of the newly available members of the thiazolidinedione family, offers a rational therapeutic approach to the treatment of type 2 diabetes. In patients whose type 2 diabetes is inadequately controlled with metformin monotherapy, the addition of rosiglitazone significantly improves glycemic control, insulin sensitivity and beta-cell function, compared with either drug alone. In addition, this combination therapy has beneficial effects on other cardiovascular risk factors. Rosiglitazone maleate/metformin hydrochloride combination therapy is well tolerated in patients with type 2 diabetes and has a favorable safety profile. This review summarizes the available evidence on the clinical efficacy and safety of rosiglitazone maleate and metformin hydrochloride combination therapy in patients with type 2 diabetes.