Glaxos Avandia Has More Heart Risks Than Actos, Study Finds
Researchers analyzed prescription data for 39,736 patients ages 66 and older who were enrolled in the Ontario Public Drug Benefit Program and began taking Avandia or Actos from April 2002 to March 2008. During the six-year study, 6.9 percent of patients on Avandia died or were hospitalized for a heart attack or heart failure, compared with 5.3 percent of those on Actos.
Avandia was the best-selling drug for diabetes in the world when it was linked to heart attacks in a 2007 study, sending sales down 63 percent from a peak of 1.4 billion pounds ($2.3 billion) in 2006 for London-based Glaxo. While Avandia and Actos increase the risk of heart failure, and both carry warnings about the danger on their labels, questions remain about other differences in heart risks between the two drugs.
The study shows that among older diabetics, Actos is associated with a lower risk of heart failure and death than Avandia, said researchers led by David Juurlink, head of Sunnybrook Health Sciences Centers pharmacology and toxicology unit in Toronto. Given the evidence of harm with Avandia and the lack of benefit beyond what is seen with Actos, its reasonable to question whether continued use is justified, they said.
The study, funded by the Ontario Ministry of Health and Long Term Care, appears today in the British Medical Journal. While its not clear what is responsible for the differences between the two drugs, Actos appears to improve cholesterol levels and may have anti-inflammatory and other beneficial effects, the researchers said.
Patient Differences
Patients getting Avandia had diabetes for a longer period of time than those given Actos, who may have been healthier when the study started, wrote Corinne de Vries from the University of Bath and David Russell-Jones from the University of Surrey in an accompanying editorial. The study emphasizes the need to avoid both drugs in patients with heart failure, though its hard to draw other conclusions from the results, they said.
The findings conflict with three previous studies that showed no difference in heart failure rates between the two drugs, said Mary Anne Rhyne, a Glaxo spokeswomen. Another more scientifically rigorous study released earlier this year found Avandia doesnt boost hospital stays for cardiac complications or death more than standard diabetes therapy, she said.
The current study was flawed because it didnt properly take into account the different doses of the drugs, she said in a telephone interview.