The sudden safety alert from America's drugs regulator, the Food and Drug Administration (FDA), about the diabetes drug Avandia leaves two vital questions unanswered. The alert follows a study that has discovered that Avandia (rosiglitazone) increases the risk of heart attack by 45 per cent.
Why, in the first place, did the drug get approved? It is part of a family of drugs known as thiazolidinediones, which were discredited in the earliest stages of their development. Another thiazolidinedione, muraglitazar, was withdrawn from the licensing process after early trials found it increased the chances of heart attack. On hearing the news, other drug manufacturers abandoned the development of their own thiazolidinedione.
So how did GlaxoSmithKline's Avandia slip through the net?
The second question concerns ongoing safety checking. It's well known that diabetics are much more prone to heart disease; it's also known that the thiazolidinediones increase that risk further. So why is it that in the eight years since approval, GSK has not undertaken a major study into Avandia's safety?
In the event, it took two researchers from the Cleveland Clinic to review 42 small studies to come up with the alarming - but hardly surprising - conclusion about the drug's dangers.
Avandia is one of the most popular of the drugs for treating type II diabetes. It's not known exactly how many prescriptions have been written for the drug, but GSK reveals that the drug's quarterly sales stand at lb414m, or lb1.65bn a year, so it's reasonable to assume that millions of tablets have been swallowed.
This beggars a third and final question: just how many people have died because of Avandia, and all the time the doctor was blaming the diabetes?
(Source: New England Journal of Medicine, May 21, 2007, published online as: 10.1056/NEJMoa072761).
E-news broadcast 24 May 2007 No.362