Stronger Warning for Some Diabetes Drugs

Makers of Certain Diabetes Drugs Agree to 'Black Box' Warning of Heart Failure Risk

Medically Reviewed by Louise Chang, MD on August 14, 2007
From the WebMD Archives

Aug. 14, 2007 -- The FDA today announced that the makers of certain type 2 diabetes drugs have agreed to strengthen the drugs' warnings about the risk of heart failure, a condition in which the heart doesn't adequately pump blood.

The strengthened warning will come in the form of a "black box" warning, the FDA's sternest warning. The upgraded warning emphasizes that the drugs may cause or worsen heart failure in certain patients.

All drugs in the class of diabetes drugs called thiazolidinediones -- which includes the drugs Avandia, Actos, Avandaryl, Avandamet, and Duetact -- will get the black box warning.

Those drugs, which are used in conjunction with diet and exercise to improve blood sugar control in adults with type 2 diabetes, already carried a warning about heart failure risk.

In June, the FDA announced that two drugs in that drug class would get a black box warning.

After reviewing postmarketing adverse event reports, the FDA determined that the entire class of thiazolidinediones needed the black box warning about heart failure risk. The FDA had asked the drugs' makers -- GlaxoSmithKline and Takeda -- to address those concerns.

"This new boxed warning addresses [the] FDA’s concerns that despite the warnings and information already listed in the drug labels, these drugs are still being prescribed to patients without careful monitoring for signs of heart failure," Steven Galson, MD, MPH, director of the FDA's Center for Drug Evaluation and Research, says in an FDA news release.

Black Box Warning

The strengthened warning advises health care professionals to observe patients carefully for the signs and symptoms of heart failure, including excessive, rapid weight gain, shortness of breath, and swelling (edema) after starting drug therapy.

Patients with those symptoms who develop heart failure should receive appropriate management of the heart failure and use of the diabetes drug should be reconsidered, states the FDA.

The warning also states that these drugs shouldn't be used by people with serious or severe heart failure who have marked limits on their activity and who are comfortable only at rest or who are confined to bed or a chair.

The FDA advises people with questions about the risks to contact their health care providers to discuss alternative treatments.

FDA's Review

The FDA states that its review of adverse event reports showed cases of significant weight gain and edema, which can be warning signs of heart failure. The FDA notes that in some reports, continuation of therapy has been associated with poor outcomes, including death.

The FDA’s review of Avandia and possible increased risk of heart attacks is ongoing. On July 30, FDA committees recommended that Avandia continue to be marketed and further recommended that information be added to the labeling for risk of heart attacks.

The new black box warning doesn't address heart attack risk.

GlaxoSmithKline states in a news release that the approval of the updated warning "allows GSK [GlaxoSmithkline] to implement changes in the label for Avandia as previously committed."

GlaxoSmithKline says it will put the heart failure black box warning on its other thiazolidinediones.

A Takeda spokesperson wasn't immediately available for comment.