Just over a decade a go a new class of drugs burst onto the diabetes treatment scene with much hyperbole and excitement. The thiazolidinediones (or TZDs) were said to target one of the root causes of type 2 diabetes - improving the body's resistance to insulin. But almost from the onset the problems and serious side effects associated with TZDs began to become clear.
The first of the TZDs (launched in 1996) was troglitazone (Rezulin). It caused severe irreversible liver failure in some patients and it couldn't be predicted who would get that problem. Several hundred people have died of liver failure as a results of treatment with Rezulin and so it was taken off the market in 2000. The response by many doctors and patients was simply to switch to a newer TZD.
The next of the TZDs was rosiglitazone (Avandia). While it does not appear to cause liver problems there is a long list of other serious side effects that it causes. It causes people to retain too much fluid in their body and to develop heart failure at a much faster rate than people who do not take Avandia. It causes weight gain and it causes people to develop thinning of the bones (osteoporosis) which increases the risk of fractures (which can be very serious indeed in older people who have diabetes). All of these were minimized by the drug companies and by people promoting the use of Avandia because they claimed that patients who kept taking it would ultimately get more benefit because of reduced complications of diabetes and fewer heart attacks and strokes. But more and more studies have shown that this is just not true. In fact people who take Avandia are MORE likely to develop heart failure, or get a heart attack or a stroke than patients who don't take this drug. On balance it is becoming clear that Avandia causes more harm than good. Fewer people are now being put on this drug but even in 2009 sales for Avandia were over a billion dollars. And many thousands of patients who are being taken off Avandia are simply being switched to the third and last remaining member of this class of drugs.
The last of the TZDs is pioglitazone (Actos) and I am sure that the company who makes it are delighting in the bad press that Avandia is getting. A recent study in the Journal of the American Medical Association (JAMA) published online yesterday compared rosiglitazone (Avandia) and pioglitazone (Actos) in over 220,000 Medicare patients from 2006-2009. This study showed clearly that, compared with pioglitazone, rosiglitazone was associated with an increased risk of stroke, heart failure and death.
National Public Radio had a nice story about this study on June 28th:
http://www.npr.org/templates/story/story.php?storyId=128174678
But how good is pioglitazone? In truth we don't yet know for sure. It certainly causes unwanted weight gain. It certainly causes a significantly increased risk of developing heart failure and of getting osteoporosis leading to bone fractures. Whether it increases or decreases your chance of being alive in 5 or 10 years remains to be proven.
Fifteen years ago before the thiazolidinediones appeared on the market people with type 2 diabetes could improve their chances of staying alive and well by doing things to REDUCE their risk of heart attacks and strokes (like quitting smoking, eating healthy, getting regular exercise, and taking statins, ACE-inhibitors, low dose aspirin, and keeping their blood pressure in a good range), and taking drugs like metfomrin sometimes supplemented with insulin to keep the blood glucose levels close to normal. And if you have diabetes you still CAN do all of those things. I see no evidence that the millions of people in the USA and around the world have had their lives improved by the use of the TZDs. And if I had diabetes myself I would certainly NOT take any of them... not even Actos.
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