Oral combination therapy with thiazolidinediones in type 2 diabetes.

Insulin resistance occurs early in the type 2 diabetes disease process, leading to progressive beta cell failure and overt diabetes. By the time the diagnosis of diabetes is made, advanced macrovascular disease may already be present. Monotherapy with a sulfonylurea or metformin can slow, but does not prevent, the progression of disease. Successful management requires combination therapy that addresses both insulin resistance and beta cell dysfunction. Clinical trials support the use of combinations of agents with complementary mechanisms of action, such as a sulfonylurea or metformin plus a thiazolidinedione. Early aggressive treatment can improve patient outcomes while reducing overall healthcare costs.