Cholesterol Drug May not be as Effective as Thought
Merck & Co. has marketed Zetia and Vytorin as pills to lower cholesterol, but a recent study is questioning the results of how well the drugs work. The study, sponsored by Merck rival Abbott Laboratories, seems to show that Zetia does not shrink buildups in arterial walls while a cheaper drug called Niaspan works significantly better. The results were presented yesterday at an America Heart Association conference and will be published today in the New England Journal of Medicine. It is believed that the results may get more doctors to prescribe Niaspan to their patients.
Niaspan is a type of B vitamin called niacin that raises HDL, the good kind of cholesterol. Zetia is part of a class of drugs known as statins that lowers LDL, the bad kind of cholesterol, by blocking its absorption. Each of these drugs has been added to some patients’ drug regimen to add to the effects of popular statins Lipitor and Crestor. This is done because many statin patients still suffer heart attacks. While Lipitor and Crestor lower LDL, they do not do this by block its absorption like Zetia. Vytorin is essentially Zetia combined with another statin.
It is estimated that Zetia and Vytorin cost between three and four dollars a day, while niacin has been sold as a generic drug for decades.
The study in question involved 363 people who had heart disease or were at risk of it, and had been taking statins for at least six years. Half were given Niaspan and the other half were given Zetia. The study ended after 208 patients were on the drugs for only 14 months because the Niaspan patients were doing much better than the Zetia patients.
While Zetia lowered cholesterol as expected, only Niaspan shrank buildups in neck arteries. Of the 160 people given Niaspan, there were two heart attacks, other heart-related problems, or heart-related deaths. Among the 165 Zetia patients, there were nine deaths.
This raised concerns that Zetia was not working the way it was expected to. Merck countered that the number of problems is too small to draw any conclusions. Their president of global human health adds that shrinking plaque is no guarantee that a heart attack will not occur. A spokesperson from Merck says that there are over 25,000 Zetia users in studies now, and independent monitors have not seen any problems.
Other cardiologists say the study shows Niaspan is doing precisely what statins are supposed to do: lower cholesterol levels. They say people with cholesterol problems will still be given statins, but the added benefit of niacin may be the drug to add if some people need further help.
Another study performed last year found that Vytorin was no more effective than the generic drug Zocor. Late last summer Merck and Schering-Plough agreed to pay $41.5 million for delaying study results that were unfavorable so they would not hurt sales of the drugs.