Thiazolidinediones: the Forgotten Diabetes Medications

PURPOSE OF REVIEW: Thiazolidinediones (TZDs) are the only pharmacologic agents that specifically treat insulin resistance. The beneficial effects of TZDs on the cardiovascular risk factors associated with insulin resistance have been well documented. TZD use has been limited because of concern about safety issues and side effects. RECENT FINDINGS: Recent studies indicate that cardiovascular toxicity with rosiglitazone and increase in bladder cancer with pioglitazone are no longer significant issues. There are new data which show that pioglitazone treatment reduces myocardial infarctions and ischemic strokes. New data concerning TZD-mediated edema, congestive heart failure, and bone fractures improves the clinician’s ability to select patients that will have minimal significant side effects. SUMMARY: Thiazolidinediones are now generic and less costly than pharmaceutical company–promoted therapies. Better understanding of the side effects coupled with clear benefits on the components of the insulin resistance syndrome should promote TZD use in treating patients with type 2 diabetes.