The September 2007 Drug Watch reported that the Food and Drug Administration (FDA) was reviewing data indicating the risk of ischemic cardiovascular events posed by the use of rosiglitazone (Avandia), an oral drug for the treatment of type 2 diabetes. The FDA finished its review of the data submitted by the drug manufacturer in May 2007 concerning chest pain, heart attack, and death attributable to cardiac causes. In response, the FDA has requested a revision to the black box warning to the one that had been added in August 2007. The warning now includes the following additional information:

A meta-analysis of 42 clinical studies (mean duration 6 months; 14,237 total patients), most of which compared Avandia to placebo, showed Avandia to be associated with an increased risk of myocardial ischemic events such as angina or myocardial infarction. Three other studies (mean duration 41 months; 14,067 patients), comparing Avandia to some other approved oral antidiabetic agents or placebo, have not confirmed or excluded this risk. In their entirety, the available data on the risk of myocardial ischemia are inconclusive.

All patients with diabetes are at some risk for developing cardiovascular disease and many also have hypertension. Because rosiglitazone is often added to diabetes drug therapy when the blood glucose level has been difficult to control, the apparently greater incidence of cardiovascular events might be attributable to pathophysiologic changes. In November 2007, the FDA concluded that all data that had been reviewed to that point do not clearly indicate that rosiglitazone poses a greater risk of cardiovascular events than that posed by other drugs used to treat type 2 diabetes. To resolve the uncertainty, the manufacturer has been asked to conduct a long-term clinical trial to compare rosiglitazone with an active control agent.

Nurses should carefully monitor patients taking rosiglitazone for signs of cardiovascular problems. Patients should be informed of the possibility of adverse cardiovascular effects and instructed to seek emergency care if chest pain or signs of myocardial infarction develop. To decrease the overall risk of developing cardiovascular disease, patients taking rosiglitazone should also be encouraged to follow a healthful diet; to control their blood pressure; and if necessary, to lose weight.