Et Tu, Zetia?

This week we find that Zetia, a commonly prescribed anti-cholesterol medication, does not work as advertised. According to the ENHANCE study, a clinical trial involving 720 patients, patients who took Zetia plus the common anticholesterol medication Zocor had the same number of heart attacks as patients who took Zocor alone. In other words, Zetia did nothing to lower heart disease risk. There was even some evidence that Zetia increased the rate of plaque accumulation in coronary arteries.

Zetia-plus-Zocor is commonly known as Vytorin. Perhaps you have seen the Vytorin ads on television, the spots with a split screen that has a food dish on one side, and a person who resembles the food on the other.

The Vytorin reps have been knocking on my door for over two years. Every month of my life I listen to one rep or another as she waves a bar chart in my face purportedly showing that Vytorin has a greater cholesterol drop than any of its competitors. Vytorin is the best, they crow. You should put all your patients on Vytorin! What will they say this coming week? My guess is they won't be coming at all.

This week, doctors all around the country are being bombarded with phone calls from nervous patients wanting to be taken off Vytorin and Zetia. But not at my office. I haven't started a patient on Vytorin in my life. One, that I can recall, on Zetia, but none on Vytorin. Not to say that I have never written a prescription for Vytorin -- I have written a few, mostly refills for patients started on it by other doctors. However, I have never started anyone on it myself.

Why not? Step into my office. Chez Hébert, you will get state-of-the-art medical care -- for the year 2003. I prescribe medication the way I buy electronics. I wait until the product has been out for a while and proven its value before I consider adding it to my personal palette. An iPhone? Maybe next year. A Blu-Ray DVD player? Next spring, thanks. I am just starting to add medications to my regular practice that came out in 2004.

This isn't simply a game, or a matter of inattentiveness. My patients are not guinea pigs, and I do not believe as a rule that they should take medications that are not thoroughly proven. All drugs that make it onto the U.S. market have proven safety in clinical trials. But these trials usually only involve a few hundred to a few thousand individuals -- not nearly enough to prove safety and efficacy for the millions more who may use them.

I prefer reading textbooks to reading medical journals. Most of the papers published in medical journals are not even applicable to my practice, but those that are usually involve small trials of a few hundred subjects. Most of these studies lack the statistical power, in my opinion, to justify changing my standard clinical practices. But over the years, as these drugs are used more and more, more physicians become familiar with them and their true value comes out. Eventually this accumulated wisdom makes its way to the major textbooks, and at that point I know I am dealing with real knowledge, not hype.

There are two criticisms people may lay against my conservative approach. First, a new drug could be a major step forward, and in my slowness to adopt it, my patients suffer. Basic blood pressure medications, like metoprolol and lisinopril, were brand new once, and by my rules I would not have used them initially. To that I would point out that for every metoprolol there is a Vioxx, for every simvastatin there is a Zetia. Since there is no way to tell which new treatment is the superdrug and which is the superdud, I would have to try them all to get any real benefit. I find a good number of the latest and greatest turn out to be nothing of the sort, and while hitting .500 might be wonderful in baseball, it is a poor record in medicine. Do you want to spend thousands of dollars a year for a medication, as Zetia users have, that may not do you any good?

The critic's rebuttal: Isn't it your job, as a doctor, to review the literature and separate out the good from the bad, and improve your average? Well, yes, but how do I do that if the data are insufficient? For example, a new class of blood pressure medications, the angiotensin receptor blockers, seems to lower pressure very well. However, so far I have seen no evidence that this very expensive (and for the drug companies, very profitable) class of drugs works any better than its dirt-cheap cousin, the ACE inhibitors. So why write for a $120 drug when a $4 drug does the same job? I don't. I will only add a medication to my routine practice if it adds something to the capabilities I already have.

The second criticism is that if we don't use the new stuff, how will we find out if it works? This is a more substantial point, but also erroneous. Medicine shouldn't be guesswork, unless guessing is all we are left with. Sometimes guessing is all we have -- all the usual treatments don't work, and so, in desperation, we have to try things. This approach is acceptable if all proven treatments are exhausted and the condition being treated is serious enough to warrant taking risks. High cholesterol is a serious condition, and even now I might use Zetia if I had a patient with dangerously high numbers and everything else failed. On the other hand, if the condition is not serious, I would be very reluctant to experiment with a brand-new drug.

A few years ago Novartis launched an irresponsible public campaign to promote a very expensive ointment called Elidel. I watched sadly as many of my peers yielded to the hype and wrote for truckloads of the stuff. Elidel is a treatment for allergic skin rashes. In the vast majority of patients, skin rashes are not serious enough to merit a medication that costs nearly $100 an ounce. And it was a new medication -- the long term risks were unknown. Sure, the reps said it was safe, but they always say that. I rarely used it. In recent years there have been some concerns that Elidel may cause skin cancers, although this has not yet been proven. At any rate, it has never been shown to work better than a $5 tube of hydrocortisone.

The Vytorin/Zetia news was a heavy blow to Merck & Co. and Schering-Plough, its manufacturers. Merck is also the maker of the ill-fated Vioxx; it is fair to say that Merck has really taken some shots in the last few years. I wish I could say I feel an ounce of pathos for them, but I can't. The ENHANCE study was completed in April 2006, and Merck and Schering-Plough have been sitting on the results for more than a year and a half. Their excuse was that the data generated by the study were complex and required careful analysis. As the study release date was pushed back again and again, medical professionals, the FDA, and finally the U.S. Congress started pressuring the companies to release the data. You know things are bad when Congress has to step in to force a drug company to release medical data that ethics would dictate should have been released immediately.

Merck and Schering-Plough are mounting two defenses against the study. First, they point out that the study is small. It looked at only 720 patients, and this small number may mean the results do not apply to the general population. Secondly, the patients studied suffered from a severe, genetic form of hypercholesterolemia that is uncommon and therefore, that the results once again do not generalize.

Cry me a river. Zetia has been out for years, and if Merck and Schering-Plough had wanted to run a large study in the general population, they could have done so. They didn't because they were afraid that if the results were not favorable, they would have killed a very profitable drug.

That is how it works in the drug business. Most drugs are not tested as throughly as they could be because drug makers know they stand to lose billions if the study results are not favorable. The only solution to this problem is for the government to start funding large-scale clinical trials for FDA-approved drugs to see if they are living up to their promises. It would be expensive, but so is spending $120 a month on a drug that doesn't work. Take your pick.

Confessions of an Anti-Stem Cell Nut

The Blistering: Chapter XVI