GlaxoSmithKline Plc's drug Avandia, the world's top-selling oral diabetes treatment, may raise a patient's chance of having a heart attack, researchers said. In the June 14, 2007 issue of the New England Journal of Medicine, Dr. Steven Nissen and his colleague Kathy Wolski, evaluated 42 studies that compared patients taking Avandia with patients not using the drug. The studies included nearly 28,000 patients, 15,560 of whom were taking Avandia.

The researchers found the risk of a heart attack was increased 43 percent among those taking Avandia. There is also a 64 percent increased risk of dying from cardiovascular causes while taking the drug. The studies concluded that there were 86 heart attacks and 39 deaths among the 15,560 Avandia patients, compared with 72 heart attacks and 22 deaths among the 12,283 patients not taking Avandia.

Avandia was FDA approved in 1999 and millions of Americans take the drug to help control their blood sugar levels. Avandia helps sensitize the body to insulin and was considered a breakthrough medication for blood-sugar control. Avandia contains rosiglitazone, which is part of the class of prescription drugs called called thiazolidinediones (TZDs). It helps the body use the insulin that it already manufactures. Avandia makes it possible for the insulin the body produces to move glucose out of the bloodstream and into the cells where it's needed for energy.

The FDA plans to take no immediate action on a label change or other measures regarding the drug. The FDA reported that some data suggests that there is a potentially significant increase in the risk but there also is risk if patients switch drugs or do not keep their blood-sugar under control. The FDA urged patients who are taking Avandia, especially those who are known to have underlying heart disease or who are at high risk of heart attack to talk to their doctor about this new information as they evaluate the available treatment options for their type 2 diabetes.

However, the agency didn't issue a call for a sharper warning label on the drug. Several experts said Avandia was another example of the FDA failing to detect a safety problem early enough.