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Why is Anyone Taking Zetia or Vytorin?

Posted by medconsumers on October 1, 2008

Vytorin and Zetia Continue to be Prescribed Despite Hints of Harms and No Proof of Benefit

There is no proof that Zetia can do anything beyond lowering cholesterol—no evidence that it can reduce heart attacks or cardiovascular disease, which, of course, is the ultimate goal. Once again, this blockbuster drug sold alone or as a combination medicine has produced negative clinical trial results. This time it failed to provide any benefit to people with heart-valve disease. Worse, there were more cancers and cancer deaths among the drug-treated participants than in those taking a placebo, though these findings are described as “due to chance.”

Release of preliminary results of this trial had generated so much interest in the media last summer that The New England Journal of Medicine allowed the final results to be available on its Web site in early September—well in advance of the planned publication date.

Zetia is a relatively new cholesterol-lowering drug that can be prescribed alone. Vytorin combines Zetia with the 22-year-old statin drug, called simvastatin (brand name Zocor), into a single pill. Last year this expensive, heavily promoted combination drug became what only can be described as a drug maker’s worst nightmare. Study results showed that Vytorin was no better at reducing atherosclerosis of the carotid (neck) arteries than the older, cheaper simvastatin alone. There was also a hint that Vytorin might actually worsen artery disease.

And if that’s not bad enough, Merck and Schering-Plough Corp., which jointly market Vytorin, had withheld these unfavorable study results for nearly two years. It was, of course, in the financial interest of both companies to do so because Vytorin and Zetia are among the top-selling drugs worldwide. Four years after both drugs went on the market, backed by an aggressive ad campaign that featured a “food and family” cholesterol theme, yearly sales reached $5.2 billion.

On its Web site last month, The New England Journal of Medicine also published an editorial and an analysis that addressed Vytorin’s possible cancer-causing effect. The analysis was based on all the people diagnosed during the new heart-valve study and two other, much larger ongoing Vytorin trials. It was conducted by an Oxford University, U.K, research team, which found no increase in cancer incidence, but did find an increase in cancer deaths among those taking Vytorin. This finding was described as due “entirely to the play of chance rather than to a true increase in cancer mortality.”

The New England Journal of Medicine editors, however, are not so sure. In an editorial, they described a plausible mechanism for a cancer-causing effect, “[Zetia] interferes with the gastrointestinal absorption not only of cholesterol, but also other molecular entities that could conceivably affect the growth of cancer cells.” Once the cancer concerns were made public again last month, the FDA announced that its own analysis is in the works.

What makes this Vytorin/Zetia story so appalling is the fact that Zetia’s only advantage over the older statin drugs is a 17% greater reduction in LDL cholesterol. Incredibly, Merck and Schering-Plough were able to sell doctors and the public on the idea that this is more important than proof that this drug can cut the risk of heart attack (which has been proven for statins prescribed to high-risk men and people with heart disease). Zetia was studied for only 12 weeks before it went on the market.

Despite their uncertain safety records, Zetia and Vytorin continue to be prescribed to people with high LDL cholesterol. After the initial bad publicity, sales of Vytorin and Zetia dropped 40% in the first six months of 2008. That’s encouraging. But the question remains: Why is anyone still taking these drugs?

Maryann Napoli, Center for Medical Consumers ©
October 2008

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