The Truth About Diabetes Mellitus Drugs

‘Medicine might be winning the battle of blood sugar control, but is losing the war against diabetes. Because type 2 diabetes, which accounts for 90% of diabetes mellitus, is largely rooted in reversible social and lifestyle factors, a medical approach alone is unlikely to be the solution. A strong, integrated, and imaginative response is required, in which the limits of drug treatment are recognised.’

Why you should be suspicious of new drugs

There is a simple financial fact you need to be aware of. Drug companies can only make lots of money on patented drugs for which they effectively have a monopoly and hence can charge a high price and fund massive marketing campaigns. Once a patent runs out, usually after fifteen years, anyone can produce the drug so the price and profit comes right down. Metformin, for example, is off patent and much less expensive. (More on this drug in a minute).

A case in point is Avandia (rosiglitazone), one of a new family of diabetes mellitus drugs called glitazones (also known as thiazolidinediones), licensed over a decade ago to treat diabetes. It works by increasing your body’s sensitivity to insulin. Sounds like a good thing to do. It’s very effective at bringing blood sugar levels down, but at a cost. Well-known side effects include: significant weight gain, fluid retention, a raised risk of heart failure and a link with osteoporosis.

What you may not have been warned about is growing evidence that it can increase your risk of a heart attack even though the first warning bells were sounded four years ago. The evidence for harm continued to grow but so too did the prescriptions. By 2009 around 500,000 prescriptions were written for the drug.

By July 2010 both the American drug regulator – the FDA – and the European one – EMA (European Medicines Agency) – considered taking it off the market and strengthening the warnings about it. The EMA did neither.

Behind the scenes a fight was on to keep the drug on the market. For instance a major plank in GlaxoSmithKline’s evidence was a big trial that reported no increase in the risk of heart disease among nearly 4,500 patients getting Avandia. Called Record it began in 2002/3 and the results were published in 2009.

However Dr Thomas Marciniak, a scientist working for the Food and Drug Administration described it as “seriously flawed” because, he claimed in his evidence to the committee, the data had been tampered with. He reported that his detailed examination of only a small percentage of all the cases had found a dozen instances where patients taking Avandia appeared to suffer serious heart problems that were not counted in the total of adverse events.

For instance, one patient was hospitalised after a severe stroke but the study record doesn’t list them as having a cardiovascular problem. In reply GlaxoSmithKline (GSK) said that it stood by the Record Study and that five further studies had all concluded Avandia was safe.

This reassuring picture was challenged further by the most high profile and persistent critic of Avandia, cardiologist Dr Steven Nissen of the Cleveland Clinic in Ohio. He had carried out the study in 2007 which first set alarm bells ringing with its conclusion that Avandia raised the risk of heart attack or stroke by 40%.

At the hearing he presented new data which estimated the number of people who would have to take Avandia for one of them to be harmed. “Even if you accept the favourable Record data, you would still get one extra heart attack for every 52 people treated with Avandia,” he said. Dr Nissen has since published a meta-analysis of all trials which makes the risks associated with Avandia very clear.

The fierce disagreements over the safety data is a prime example of why making informed decisions about drugs can be tricky. During the years between Dr Nissen’s original paper and last years’s hearings the official advice was that the “benefits outweighed the risks” for Avandia. However many diabetes clinicians didn’t agree. “We have had serious doubts about the safety of Avandia for a number of years,” says Dr Ralf Abraham who heads a private clinic – the London Diabetes and Lipid Centre.

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