Just as Catholic cardinals condemn paedophilia, so mainstream medicine formally rejects treatments not supported by evidence in the form of clinical trials. But in reality interfering with novices or failing to come up with the evidence, providing of course a drug is involved, doesn’t necessarily mean banishment. Both dodgy priests and drugs can remain on the job for years. But while we’ve long known about the priests – and still find the hypocrisy hard to stomach – cases of the dodgy drugs are less familiar.
So here is a particularly glaring one. Over two million prescriptions were written for the cholesterol lowering drug ezetimibe in 2011, even though there is no evidence that it does anything to reduce the risk of heart disease, which is the only reason you would take it. It’s been available on the NHS for ten years and in 2011 we taxpayers spent 71 million pounds on those prescriptions. Worldwide sales are about two billion annually.
It’s topical because last month the makers Merck paid out 688 million dollars to settle claims in America that it had defrauded shareholders by withholding the results of a negative trial in 2008. The drug, called Vytorin in the States (Ezetrol in the UK), is actually a combination of two ingredients – ezetimibe (zetia in the States) and simvastatin (Zocor in the States) the most widely used cholesterol-lowering statin.
An unqualified disaster
The combination is recommended for people who have failed to get their cholesterol low enough with a statin alone. It works in a different way to statins by blocking cholesterol absorption in the guts. The shareholders claimed that they weren’t able to make “informed decisions” because the company took a year to release the results of a trial described as an “unqualified disaster.”
The way the trial failed is interesting. The combination certainly lowered cholesterol very effectively. Patients with a high risk of heart disease who got the combination saw their cholesterol drop by 58% compared with 41% for those on the statin alone. Trouble was that this had no effect on their risk of heart disease. The trial measured how much the drug combo reduced plaque build-up in an artery in the neck. While the statin alone decreased plaque, the combo slightly increased it.
The claims were based on possible financial loss because the trial showed ezetimibe was ineffective and so, you might assume wouldn’t sell very well, if at all. Bizarrely it seems to have made little difference to sales. What does that tell us about evidence based medicine? But there is something even more shocking that follows from this trial. The fact of lowering cholesterol on its own doesn’t cut your risk of heart disease.
Does lowering cholesterol cut cardiovascular risk?
This has also been largely ignored but this raises an even bigger question about the practice of evidence based medicine. Could it be that that statins don’t lower heart disease risk by lowering cholesterol but by some other route – possibly by reducing inflammation? Even so, calls to lower cholesterol are as insistent as ever.
And there is a third issue. The company has to pay out half a billion dollars for imperilling shareholder’s profits but nothing for condemning millions of patients to continue taking a drug that had a big question-mark over it.
And if you believe that drug prescribing always follows the evidence it’s hard to explain why use of the drug is increasing significantly. Just before the failed Enhance trial was completed in 2007, there were 1.7 million prescriptions written in England for ezetimibe, in the year the results came out (2008) prescriptions went up to 1.9 and by 2011 after more failures it was up to 2.2 million.
Launched with excited claims
The piece I wrote about ezetimibe at the time of the Enhance trial in the Daily Mail gives more background details. By then the drug had already been on the market for four years, having been with launched with excited claim that it offered doctors a whole new way of fighting cardiovascular disease.
In 2010 ezetimibe failed again. A study known as ARBITER 6-HALTS, published in Journal of American College of Cardiology, compared the effect of adding the B vitamin niacin to a statin with the benefit of adding ezetimibe. Again the test was the reduction of the thickness of plaque in an artery leading to the brain.
While added niacin “significantly regressed the atherosclerosis” the addition of ezetimibe had no effect. Dr John Briffa’s blog has details of some other failed trials.
With one bound the undead is free
Just to be sure there wasn’t a successful trial lurking, I did a Medline search last week and found a “clinical update” of ezetimibe published last year. After a detailed review of all the trials the authors write: “To date no randomised trial has shown a significant reduction in clinical events with combination therapy using ezetimibe plus statin versus statin alone.”
And that you might think would be that. Final nail in the coffin surely. But with one bound this undead drug is free. There is yet another trial on-going and until that reports the authors conclude: “Based on the current available data ezetimibe should remain a viable adjunct to statin therapy.” Two of the three authors on the paper disclose that they are speakers for Merck.
When the topic of CAM and evidence based medicine comes up and anyone mentions homeopathy and the outrageous waste of four million on an evidence free placebo, just say “ezetimibe”. It doesn’t even have a placebo effect.