What are the thiazolidinediones (TZDs) and how do they differ from other pharmacotherapies?
The thiazolidinediones (known commercially as the glitazones) are the newest class of OHAs. The TZDs are insulin sensitizers; they reduce insulin resistance and increase glucose uptake into peripheral tissues, which results in decreased insulin levels. The TZDs are different from all other OHAs, most of which increase insulin by directly affecting the beta cells of the pancreas. The sulfonylureas work by stimulating the beta cells of the pancreas to make more insulin. Metformin, the only biguanide, inhibits glucose production in the liver and sensitizes organs to the presence of an endogenous, direct effect on the beta cells of the pancreas to increase insulin production. The prandial glucose regulators, repaglinide and nateglinide, work by stimulating insulin release from the beta cells.
