The head of the Food and Drug Administration told the House Committee on Oversight and Government Reform yesterday that the label of the diabetes drug Avandia will now carry a “black-box” warning.

Commissioner Andrew von Eschenbach revealed that the FDA is also ordering the same for another diabetes medication, Actos, made by Takeda Pharmaceuticals. Late last month, a study published in the New England Journal of Medicine said GlaxoSmithKline’s Avandia raised the risk of heart attack.

The announcement about Avandia comes at a time when some lawmakers are rebuking the FDA and calling for tighter regulation of the pharmaceutical industry. The controversy intensified when Dr. John Buse, president-elect of the American Diabetes Association, told the committee of vague threats to sue him eight years ago after he had drawn attention to Avandia’s heart attack risks.

“Despite additional warnings from outside experts, despite the millions of patients who rely on Avandia to control their blood sugar, and despite the potential risks involved, [the] FDA never required the manufacturer to conduct a thorough post-market study of its heart risks,” said Rep. Henry Waxman, chairman of the committee.

Wednesday’s hearing was called after the NEJM’s analysis in May came to the conclusion that Avandia could cause patients taking it to have a 43% greater risk of heart attack.

Von Eschenbach informed the committee that the FDA continues to assess a number of studies and analyses on Avandia’s effects on people with diabetes. In three weeks, the FDA will have a group of outside experts review the data.

GSK executives claimed to be surprised by von Eschenbach’s announcement but said they would nevertheless comply. The British-based drug maker claims that Avandia is safe and that it has data to prove it, although some doctors and researchers have their doubts about that.