The safety of the controversial diabetes drug Avandia (rosiglitazone) was attacked in a new analysis by German researchers, who found little evidence that the drug improved the quality or length of life and concluded it could actually worsen complications of the disease. Their conclusions were based on a review of pooled data from 18 past trials involving 8 000 patients.
Dr Bernd Richter of Duesseldorf's Heinrich-Heine University, who led the research, questioned whether it was ethical to conduct any further clinical tests with Avandia, since "less dangerous" alternative treatments were available.
Drug maker Glaxo dismissed these findings as misleading and said it strongly disagreed with the conclusions, which were published in the Cochrane Library journal.
Avandia has been under a cloud since May, when top US cardiologist Dr Steven Nissen published a pooled analysis of 42 previous trials that showed it increased the risk of heart attack by 43 percent.
Richter said his research was conducted independently of Nissen's, and the timing was a coincidence, though the two teams reached similar conclusions.
The German analysis found that Avandia produced about the same reductions in blood sugar levels as other oral antidiabetic drugs, but patients taking Avandia gained up to 11 pounds (5 kilograms) and the risk of oedema, or swelling, doubled.
Avandia was also linked to heart failure and bone fractures.
"I see a bundle of adverse effects, and I don't see really good positive effects," Richter told Reuters.
Small risks, big effects
He noted that even very small risks could be significant for such a widely used medicine. "On a global scale, tiny risks can translate into big effects, because millions of people are taking this drug," he said.
Glaxo said Richter's analysis provided no new evidence about the use of Avandia in clinical practice.
"It's looking at a very thin slice of the total available evidence for rosiglitazone and really ignoring a huge amount of research," Ronald Krall, chief medical officer of the world's second-largest drugmaker, said in a telephone interview.
Krall said Glaxo has studied Avandia in more than 52 000 patients, and this much larger dataset showed the drug had a similar safety profile to other oral antidiabetic drugs.
The issue will come to a head on July 30, when US Food and Drug Administration advisers meet to discuss the drug's safety. Krall said he is confident Glaxo has a compelling body of evidence to present at the meeting. – (ReutersHealth)