On August 14, 2007, the U.S. Food and Drug Administration (FDA) announced it was placing a black box warning on a class of diabetes drugs that includes Avandia. The warning, which is the most serious warning the agency can give, says the drugs are linked to an increase in heart failure.

The drugs receiving the warning are in a class of antidiabetic drugs called thiazolidinedione. The drugs which will receive the black-boxed warning about heart risks include:

Avandia (rosiglitazone) Actos (pioglitazone) Avandaryl (rosiglitazone and glimepiride) Avandamet (rosiglitazone and metformin) Duetact (pioglitazone and glimepride)

The FDA reviewed adverse event reports for the drugs and found cases of significant weight gain and edema (swelling), which are considered warning signs of heart failure. Continuation of these therapies has also been associated with patient deaths.

Heart failure is a condition characterized by the heart’s inability to properly pump blood. It is a condition that develops over time, and differs from a heart attack.

GlaxoSmithKline manufactures Avandia, Actos and Avandaryl. Avandia was the focus of a July 2007 FDA review because of a possible link to heart attacks. The panel agreed to allow the drug to continue to be marketed.

Takeda manufactures Avandamet and Duetact.

Sources: Jennifer Corbett Dooren, “FDA requires Avandia, Actos to have ‘black box’ warning,” Wall Street Journal, August 15, 2007; “Manufacturers of some diabetes drugs to strengthen warning on heart failure risk,” Food and Drug Administration [Press Release]; August 14, 2007; “Information for Healthcare professionals,” Food and Drug Administration [Information Sheet], August 14, 2007; “Information for Healthcare professionals,” Food and Drug Administration Information Sheet, August 14, 2007.