The consequences of deadly Avandia side-effects are now being seen in the general population, a new study has found. Previously, evidence that Avandia placed patients at an increased risk of heart attacks had only been seen in clinical trials. But now, Canadian researchers have found that patients taking the controversial diabetes drug who are not enrolled in clinical trials are showing increased evidence of heart attacks and other cardiac problems.
Avandia’s heart attack link came to light when an analysis of 42 clinical trails published by the Cleveland Clinic in May showed that patients taking the drug had a 43% higher risk of having a heart attack. Just last month, the Food & Drug Administration (FDA) announced the addition of a long-awaited black box warning for Avandia’s increased risk of heart attacks. However, many patient advocates and FDA critics thought the black box warning was a weak response to Avandia’s safety issues, and have called on GlaxoSmithKline, the maker of Avandia, and the FDA to pull the drug from the market.
Now, it seems that Avandia side effects have reached the general public. That is made clear in a study conducted by scientists at the Institute for Clinical Evaluative Sciences in Toronto, Canada. Researchers there analyzed data for 159,026 older adults who were treated with at least one oral diabetes drug between 2002 and 2005 and were entered in an Ontario healthcare database. The subjects were followed through March 2006. During an average follow-up period of 3.8 years, 7.9 percent of the patients were hospitalized for congestive heart failure, 7.9 percent were hospitalized for a heart attack, and 19 percent died, according to the researchers’ report in Journal of the American Medical Association. Further analysis revealed that the risks were largely confined to patients who were using Avandia, known generically as rosiglitazone.
The Canadian researchers wrote that their findings “provide evidence from a real-world setting and support data from clinical trials that the harms of thiazolidinediones may outweigh their benefits, even in patients without obvious…cardiovascular disease”.
This latest research does not bode well for Avandia. Earlier this month, pharmacy benefit managers HealthTrans and Prime Therapeutics announced that they would be dropping the controversial diabetes drug from their value-based prescription drug formularies as of January 1, 2008 because of safety concerns. In October, the Department of Veterans Affairs (VA) announced that it was removing Avandia from its prescription drug formulary because of its heart attack risks. The VA said that it would still make Avandia available for patients who were already taking it and wanted to continue. But the decision means that patients not currently prescribed Avandia will not be able to get it through the VA in the future. Prior to its announcement, the VA accounted for about 8 percent of Avandia sales.
Avandia was once GlaxoSmithKline’s second-biggest selling drug, with worldwide revenue of $3.2 billion in 2006, but sales have plunged since May, with US sales down 48 percent in the third quarter from a year ago.