These findings were part of a study examining the effects of Vytorin, a combination drug that consists of Zetia (ezetimibe) and Zocor (simvastatin), in the prevention of heart disease. Approximately 700 individuals with very high, inherited cholesterol levels participated in this study. Researchers were examining the effects of Vytorin or Zocor alone on LDL cholesterol, plaque formation, and side effects.
Over a two-year period, it was found that Vytorin lowered LDL cholesterol by 58% versus 41% with using Zocor alone. Although no significant side effects were noted, it was found that liver enzymes were slightly more elevated in individuals taking Vytorin than those taking Zocor. However, the most striking finding was that plaques in the carotid artery were thicker in participants taking Vytorin than those individuals taking Zocor alone. Plaque formation causes atherosclerosis, which can lead to forms of heart disease, such as a heart attack or stroke. This finding was unexpected, and may suggest that the popular cholesterol-lowering drug Vytorin does not provide any benefit in the protection against heart disease when compared to a statin.
While these findings are bothersome, you should not stop taking Zetia without discussing your concerns with your healthcare provider.
Sources:
Third Report of the National Cholesterol Education Program
(NCEP) Expert Panel on Detection, Evaluation, and Treatment of
High Blood Cholesterol in Adults (PDF), July 2004, The National Institutes of Heath: The National Heart, Lung, and Blood Institute.
Merck Press Releases. 2008. Available at: http://www.merck.com/newsroom/press_releases/product/2008_0114.html. Accessed 14 January 2008.

