The U.S. Food and Drug Administration announced today that the manufacturer of Avandia (rosiglitazone), a drug used to treat type 2 diabetes, has agreed to add new information to the existing boxed warning in the drug's labeling about potential increased risk for heart attacks.

People with type 2 diabetes who have underlying heart disease or who are at high risk of heart attack should talk with their health care provider about the revised warning as they evaluate treatment options. FDA advises health care providers to closely monitor patients who take Avandia for cardiovascular risks.

"FDA has moved expeditiously to review the cardiovascular risks of this drug so that we could inform patients and doctors at the earliest possible time of our findings," said Janet Woodcock, M.D., FDA's deputy commissioner for scientific and medical programs, chief medical officer, and acting director of the Center for Drug Evaluation and Research. "FDA remains committed to making sure that doctors and patients have the latest information about the risks and benefits of medicines."

Avandia, manufactured by GlaxoSmithKline (GSK), Philadelphia, Pa., was approved in 1999 as an adjunct to diet and exercise to improve control of blood sugar levels. Avandia is approved to be used as a single therapy or used in combination with metformin and sulfonylureas, other oral anti-diabetes treatments.

During the past year, FDA has carefully weighed several complex sources of data, some which show conflicting results, related to the risk of chest pain, heart attacks and heart-related deaths, and deaths from any cause in patients treated with Avandia.

The revision of Avandia's existing boxed warning – FDA's strongest form of warning – includes the following statement:

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.

The previous upgraded warning, added to certain diabetes drugs (in class of drugs related to Avandia) on Aug. 14, 2007, emphasized that these types of drugs may worsen heart failure, a condition in which the heart does not adequately pump blood, in some patients.

To date, no oral anti-diabetes drug has been conclusively shown to reduce cardiovascular risk. Consequently, the agency also will be requesting that labeling of all approved oral anti-diabetes drugs contain language describing the lack of data showing this benefit.