FDA Logo On Tuesday, the U.S. Food and Drug Administration (FDA) said manufacturers of certain type 2 diabetes drugs have agreed to add a stronger heart failure warning on drug labels.

Heart failure is a condition that occurs when the heart does not adequately pump blood.

The FDA said the information will be included in the form of a “boxed” warning — the FDA’s strongest form of a warning — emphasizing the drugs might cause or worsen heart failure in some patients.

The FDA also said that the warning involves the thiazolidinedione class of anti-diabetic drugs. The products include the brands Avandia, Actos, Avandaryl, Avandamet and Duetact, all of which are manufactured by GlaxoSmithKline and Takeda.

Dr. Steven Galson, director of the FDA’s Center for Drug Evaluation and research said, “This new boxed warning addresses FDA’s concerns that Â… these drugs are still being prescribed to patients without careful monitoring for signs of heart failure.”

The strengthened warning advises health care professionals to observe patients carefully for the signs and symptoms of heart failure, including excessive and rapid weight gain, shortness of breath, and edema after starting drug therapy. The FDA said the use of the drugs by such patients should be reconsidered.