Study: Avandia riskier than Actos for older diabetics

Older patients taking GlaxoSmithKline P.L.C.'s diabetes drug Avandia had an increased risk of death and heart failure compared with similar patients taking Actos, a competing diabetes drug.

The study of about 28,000 patients, all of them older than 65, also concluded that neither drug should be considered very safe.

The study, published yesterday in the Archives of Internal Medicine, was based on Medicare claims data from patients in Pennsylvania and New Jersey.

Those who took Avandia had a 15 percent higher rate of death and a 13 percent greater risk of heart failure compared with those taking Actos, made by Takeda Pharmaceuticals North America Inc.

"This study confirms the safety concerns that have been raised for rosiglitazone compared with pioglitazone, which, in turn, also cannot be considered a very safe drug given its well-documented effect on the risk of congestive heart failure," the study's authors said.

The study found no difference in heart attack and stroke risks. But because 75 percent of diabetics die from heart-related causes, the researchers think heart attacks and strokes likely contributed to the overall increased deaths in the Avandia group.

Rosiglitazone is the generic name for Avandia, pioglitazone for Actos. Avandia has been under intense scrutiny since May, when a New England Journal of Medicine study concluded that the drug increased the risk of cardiovascular problems in those who took it.

In a statement yesterday, GlaxoSmithKline said it "strongly supports the safety and efficacy of Avandia based on extensive clinical trial experience and widespread post-marketing use."

The company said the study, led by researcher Wolfgang C. Winkelmayer, a doctor at Brigham and Women's Hospital in Boston, was limited, because subjects were not assigned to take the drugs randomly. This was because the study relied on people already taking one of the drugs, and those decisions were made by their doctors.

The company also said the difference in number of Avandia and Actos users who died could be attributed to differing rates of cardiovascular disease and other problems in each group.

Winkelmayer agreed that the inability to randomly assign study subjects to each drug was a shortcoming. But he said he believed the results.

Both Avandia and Actos now carry a so-called black box warning, the most serious type, about increased risk of heart failure among users.

The research received funding from several sources, including the American Heart Association, GlaxoSmithKline and drugmaker Amgen Inc.