Avandia has come under fire again, after two more studies raised additional concerns over the safety of the diabetes medication.
The new research could add to pressure on the Food & Drug Administration (FDA) to further regulate the controversial drug, and will undoubtedly cause many more doctors to cease prescribing Avandia. Sales of Avandia had already plunged over the summer after an earlier study indicated the drug could increase a patient's risk of suffering a heart attack.
Both studies were published in the Journal of the American Medical Association. The first found that Avandia doubled the risk of a patient developing heart failure, and increased the chance of heart attack by 42 percent. The second study found that another diabetes drug, Actos, actually provided patients some protection from heart attacks, strokes and death, although it also increased the risk of heart failure.
An accompanying editorial only added fuel to the controversy by claiming that had Avandia's heart attack risk been known in 1999, it would have never been granted FDA approval.
Avandia has been a subject of debate since May 21, when an analysis of 42 clinical trails published by the Cleveland Clinic showed that patients taking the drug had a 43-percent higher risk of having a heart attack. Following the publication of that study, it was revealed that in 2005, GlaxoSmithKline, Avandia's manufacturer, had informed the FDA of a study it had conducted that produced similar results.
However, both the agency and the manufacturer felt that more investigation was needed before conclusions could be made about Avandia's possible safety issues. As a result, the cardiac problems were not made public until the Cleveland Clinic published its analysis in May.
The first of the two studies published in the Journal was conducted by researchers from Wake Forest University. It was similar to the analysis published by the Cleveland Clinic in May, but was limited to four long-term clinical trials. The results of the Wake Forest analysis were strikingly similar to the Cleveland Clinic's earlier findings.
The second was conducted by the Cleveland Clinic, and analyzed data from 19 clinical trails on Actos. The study found that Actos actually lowered the risk of heart attacks, stroke and death by 20-percent. Although Actos also increased a patient's risk of heart failure, those problems are reversible.
Dr. Sonal Singh, a co-author of the Wake Forest Study, told the New York Times that doctors should reconsider prescribing Avandia. "There are older and cheaper drugs that are far better to treat diabetes." He also said that in addition to the risks of heart failure and heart attacks, Avandia also can lead to blindness, and can cause bone fractures in women
In July, the FDA convened a panel to discuss the issues surrounding Avandia's heart attack risk. The panel voted 20-3 that the drug did in fact raise the chance of heart attacks, yet the panel still voted 22-1 to allow it to remain on the market.
As a result of that meeting, new warnings were added to Avandia's label. But in an editorial published along with the new studies, two doctors from Boston's Brigham and Woman's Hospital wrote that had such a lopsided vote on Avandia's heart risks taken place prior to its approval, the drug would never have gotten on to the market. And Dr. Steven Nissan, an author on both Cleveland Clinic studies, told USA Today that the new research should put more pressure on the FDA to reconsider Avandia.