The continuing controversy surrounding the cardiovascular risk of the diabetes drug Avandia has led to sharp declines in its use and a surge in sales of the competing drug Actos, in part because the latter is perceived to be safer. Sales of Avandia, as high as $3.4 billion in 2006, have fallen to about $1.1 billion this year, while those of Actos have climbed to about $4.6 billion. But new results reported Monday suggest that the cardiovascular risks of the two drugs are about the same.
Both drugs are members of the family known as thizolidinediones, which decrease the insulin resistance of body tissues and modify the production of cholesterol. They are considered among the most powerful drugs for treating Type 2 diabetes but have been plagued by reports of side effects. A 2007 study of more than 200,000 Medicare patients suggested that Avandia, known generically as rosiglitazone, increased the risk of heart attack, cardiovascular disease, stroke and death by 30% to 40% compared with metformin and other, older diabetes drugs. That study also suggested that the increased risk was not observed with Actos, known generically as pioglitazone.
That study led the Food and Drug Administration to require a stronger warning label on Avandia to alert consumers to the risks. After more reports of increased risk with the drug, an FDA advisory panel last month recommended even stronger warning labels on the Avandia package, although it said that the drug should be kept on the market because the benefits outweigh the potential risks. The panel also recommended that no more patients be enrolled in a prospective study comparing Avandia and Actos directly.