Yet another study suggests problems with Avandia. This time, however, Actos also gets tagged. An article published in this week’s edition of the Journal of the American Medical Association concludes the two drugs pose a significantly greater risk of heart attack, congestive heart failure and death in older patients compared with other diabetes meds. (This is the abstract).

This is only the latest difficulty for Glaxo, which has seen Avandia sales plummet this year following a controversial meta-analysis last spring that linked the drug to an increased risk of heart attacks. The FDA allowed the pill to remain on the market, but slapped a second Black Box warning on the labeling. The troubles facing the med, which was once a best seller, is now cited as a key reason for Glaxo’s plans to downsize.

In the JAMA study, researchers at Toronto’s Institute for Clinical Evaluative Sciences studied the risk of heart failure, heart attack and death among diabetic patients aged 66 or older. They analyzed data from various healthcare databases in Ontario that included 159,026 diabetics, who were tracked for nearly four years until March 2006. Patients given Avandia and Actos had a 60 percent increased risk of congestive heart failure, a 40% increased risk of heart attack and a 29% increased risk of death, compared with other diabetes meds, according to the study.

“These findings provide evidence from a real-world setting and support data from clinical trials that the harms of (this class of drugs) may outweigh their benefits, even in patients without obvious baseline cardiovascular disease,” the researchers wrote. “Further studies are needed to better quantify the risk-benefit trade-offs associated with TZD therapy and to explore whether the hazards associated with these agents are specific to (Avandia).”

In a statement, Glaxo says “the retrospective analysis of the Ontario Drug Benefit (ODB) database has significant limitations and generates misleading conclusions regarding acute myocardial infarction and death. These conclusions are inconsistent with a more robust body of evidence from large, long-term, prospective, well-designed clinical studies, including ADOPT and RECORD.” (Here is the rest of the statement).