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 Another thiazolidinedione, muraglitazar, was withdrawn from the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 £414m, or £1.65bn 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 [Subscribe]
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