Avandia, the widely used diabetes drug manufactured by GlaxoSmithKline PLC got a new warning label Wednesday telling patients that it may, or may not, increase the risk of heart attacks.
Thus far, studies by the Food and Drug Administration have been too contradictory to tell if Avandia really is riskier than other Type 2 diabetes medications.
Still, the FDA put the controversy in a black box on the drug's label — the most severe warning the agency can require — at the behest of its scientific advisers, while it awaits further research to settle the issue.
Further complicating the new warning label: Patients may need a medical dictionary to interpret it. The warning says that Avandia may be associated with "myocardial ischemic events such as angina or myocardial infarction." In layman's terms, that's chest pain or a heart attack.
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.
Type 2 diabetics who also have heart disease or are at high risk for it should talk with their doctor about Avandia's potential risk as they decide among treatment options, the FDA advised.
GlaxoSmithKline PLC has agreed to begin a major new study comparing that drug to another active blood sugar-lowering medication to better understand if there is a risk.
About 1 million Americans with Type 2 diabetes use Avandia.