Even if I had another topic planned, how could I not write this month about Zetia? Another example of panacea to panic, another billion dollar drug toileted based on preliminary studies. More than 4 million Americans taking this drug or the combination drug Vytorin (Zetia plus Zocor) now not sure what to do.
But what should users of Zetia and Vytorin do? It has been well established that lower LDL or bad cholesterol is good for the heart. The surprising finding of the ENHANCE trial was that in the groups that received Zetia, despite significantly lower cholesterol, there was not a corresponding regression of plaques in the carotid arteries. Since carotid disease is somewhat predictive of coronary disease, this has raised red flags about the effective- ness of Zetia at preventing heart attacks and disease.
But as usual, the misreporting of the ENHANCE trial in the media has obscured several important facts about the drug itself. First and foremost, there have been NO studies yet about cardiac events. We simply don't know whether the regular use of Zetia as part of a strategy of cholesterol-lowering leads to less clinical heart disease or not. Though cholesterol-based plaque clogging arteries is part of the problem, it is not the whole story. Second, the study took place over two years, and long-term effects on the arteries are not known. The conclusions based on this preliminary information has quickly led to the trashing of a drug in the media that may still have important uses.
ENHANCE does bring up some of the intrinsic limitations of combination drugs. I have always been wary of combining two active chemicals in the same pill because it may be difficult to determine which drug is doing what.
The real problem here is not with a drug that lowers cholesterol by blocking its re-absorption in the gut, but with the media's kneejerk attempts to marginalize this drug into non-existence based on a preliminary and limited study.
Marc Siegel, MD, is an internist and associate professor of medicine at New York University and the author of False Alarm: The Truth About the Epidemic of Fear