WASHINGTON -- Avandia, a diabetes drug that could increase the risk of heart attacks in some patients, got a tougher warning label yesterday, but the government decided against the more drastic step of halting sales.
The Food and Drug Administration advised patients with Type 2 diabetes who take Avandia to consult their doctors if they suffer from heart disease or are at high risk of a heart attack, and it urged physicians to closely monitor those patients. But the agency rejected calls to withdraw the oral drug from the market, saying its potential heart attack risks require further study.
Seven million patients have taken Avandia since it was approved in 1999, but use of the drug has plunged since a prominent cardiologist reported in May that the prescription medicine raised the risk of heart attacks.
The report, in the New England Journal of Medicine, sparked requests for a halt to sales of the drug and raised fresh concerns about the government's ability to protect Americans from unsafe drugs. At congressional hearings last summer, critics assailed the FDA for ignoring red flags.
But during the deliberations leading to the tougher warning, the agency's staff was split over questions about the drug's safety and what the appropriate government response should be.
The FDA's deputy commissioner, Dr. Janet Woodcock, said in a conference call with reporters that officials concluded the risks weren't clear enough to prompt more drastic action, such as stopping sale of the drug.
Agency officials emphasized that scientific studies aren't conclusive on whether taking Avandia increases the risk of a heart attack. They also said it wasn't clear how the side effects of Avandia compare with those from other oral diabetes drugs.
To get a firmer understanding of any link, the FDA asked GlaxoSmithKline, maker of Avandia, to study potential heart-related risks. The company said it would conduct the long-term study and expressed confidence that new research would support "both the benefit and safety of Avandia."
While the company's statement was muted, it had to be pleased with the FDA action. The new warning says one review found a higher risk of heart attack, while three other studies and the available evidence generally were inconclusive.
By contrast, the Canadian government said last week that it no longer approved Avandia's use by many Type 2 diabetes patients.
The FDA language is not as strong as an existing warning that recommends against prescribing Avandia to patients who suffered heart failure.
In taking its latest action, the FDA also asked that labels for other oral diabetes drugs make clear that there is no evidence to indicate they reduce the risk of stroke, heart attack and other heart-related events.
Dr. Steven E. Nissen, the Cleveland Clinic cardiologist whose report highlighted concerns about the safety of Avandia, said the new warning wasn't strong enough. He said physicians need better direction from the government about whether to prescribe the drug while they await the results of the long-term study, which won't be completed until 2014, according to FDA officials.
"That's really too long to wait for answers," Nissen said. "We really need to guide physicians on what to do now and, unfortunately, the FDA statement doesn't provide much clarity."
Dr. James H. Mersey, chief of the endocrinology division at Greater Baltimore Medical Center, said he would make sure to tell diabetes patients about the safety concerns highlighted in the new warning, as he has been doing since questions about Avandia were raised. He said he would continue prescribing Avandia and competing drugs.
"The warning to me makes no difference. I'm very aware of the data," Mersey said.
The changes to Avandia's label also apply to the labels for two related drugs sold by Glaxo, Avandamet and Avandaryl.
The Food and Drug Administration advises patients with Type 2 diabetes who take Avandia to consult their doctors if they suffer from heart disease or are at high risk of a heart attack.