Study deals blow to Merck cholesterol drugs Zetia and Vytorin

ORLANDO, Fla. -- A new study raises fresh concerns about Zetia and its cousin, Vytorin -- drugs that are still taken by millions of Americans to lower cholesterol, despite questions raised last year about how well they work.

In the study, Zetia failed to shrink buildups in artery walls while a rival drug, Niaspan, did so significantly. Zetia users also suffered more heart attacks and other problems, although the numbers of these events are too small to draw firm conclusions.

"This study provides no evidence that would reassure us that this drug is beneficial, and it provides some evidence that it may be harmful," said Yale University cardiologist Dr. Harlan Krumholz, who had no role in the study.

The results, presented yesterday at an American Heart Association conference and published online by the New England Journal of Medicine, are likely to move more doctors away from prescribing Zetia and Vytorin.

Statins such as Lipitor and Crestor have long been used to lower LDL, or bad cholesterol, and are known to cut the risk of heart problems. Nevertheless, many statin users still suffer heart attacks, so doctors have been testing adding a second medicine to further lower risk.

One they are trying is Niaspan, a slow-release version of niacin, a type of B vitamin that raises HDL, or good cholesterol. Another is Zetia, which lowers bad cholesterol in a different way than statins do, by blocking its absorption in the gut.

Vytorin is a pill that combines Zetia with a statin. Both are sold by Merck & Co. of Whitehouse Station, N.J. Niaspan is made by North Chicago, Ill.-based Abbott Laboratories. All three of these drugs cost between $3 and $4 a day, though niacin has been sold as a cheap generic for decades.

The new study was sponsored by Abbott, and several study leaders have been paid speakers or consultants to the company or to rival drugmakers.