Criticism of the diabetes therapy Avandia is reaching a fever pitch. The drug has been in the spotlight since 2007, when it was linked to heart attacks. Yesterday, two new studies analyzing outcomes for hundreds of thousands of people reaffirmed that the drug can be hazardous for the heart and pegged the degree of risk close to the 2007 finding. The company that makes Avandia, GlaxoSmithKline, shot back with a denial that Avandia is dangerous. But pressure to pull it from the market is running high, and two advisory panels from the U.S. Food and Drug Administration (FDA) are meeting in a couple weeks to discuss what to do.
The new studies were led by researchers who have long voiced concerns about Avandia, also known by its generic name rosiglitazone. The first was published online by The Journal of the American Medical Association. There, David Graham, who works in drug safety at FDA, and colleagues turned to a database of 227,571 people on Medicare, meaning they were over the age of 65. All of them had been treated with either Avandia or Actos, (pioglitazone), a very similar drug.
Data about drug use were available thanks to the Medicare prescription drug benefit, which took effect in January 2006 . Graham's group found that people taking Avandia had about an 18% higher risk of heart attack, stroke, heart failure, or death compared with those on Actos, which other work has shown is just as effective.
The second study was led by cardiologist Steven Nissen at the Cleveland Clinic in Ohio; it was Nissen who, 3 years ago, set off the Avandia firestorm with a meta-analysis of 42 Avandia trials that he said suggested an increased risk of heart attack. In his latest paper, published with his colleague Kathy Wolski and released online yesterday in the Archives of Internal Medicine, Nissen updated his previous meta-analysis by analyzing 56 trials and found one extra heart attack for every 52 patients on the drug.
Although both studies have limitations, an editorial accompanying Graham's paper considered the findings compelling: "Accumulating concerns about rosiglitazone make it difficultto advance a cogent argument regarding why, exactly, a patient might want to receive the drug." FDA advisers meet 13 July to give their own judgment on whether the drug is safe enough to be used.