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Addition of Ezetimibe to Simvastatin Ineffective for Reducing Carotid Artery Blockage

En Español (Spanish Version)

High cholesterol , too much cholesterol in the blood, may lead to blockages in arteries that cause heart attacks and strokes . Diet and exercise help reduce cholesterol but are not always enough to prevent cholesterol related diseases. There are many medications that have been shown to reduce cholesterol and prevent heart attacks and strokes. A new medication, ezetimibe, was developed recently to reduce cholesterol when taken together with “statin” type cholesterol medications.

A recent press release from the manufacturer, Merck/Schering-Plough, reported that ezetimibe when added to simvistatin, did not reduce arterial blockage in the carotid arteries (major source of blood flow to the brain). Blockage in theses arteries means blood flow to the brain is decreased and may cause a stroke.

About the Study

The study call The Effect of Combination Ezetimibe and High-Dose Simvastatin vs. Simvastatin Alone on the Atherosclerotic Process in Patients with Heterozygous Familial Hypercholesterolemia (ENHANCE) is a randomized trial. The purpose of the study was to evaluate the effect of ezetimibe 10 mg plus simvastatin 80 mg (known as Vytorin) on artery blockage.

A total of 720 patients with heterozygous familial hypercholesterolemia (a severe form of high cholesterol) were randomly placed into two groups. One group received the combination drug, Vytorin, and the second group received simvastatin (Zocor) 80 mg alone. The study then followed the patient for two years. At the beginning of the study these patients had an average LDL (low-denisty lipoprotein) cholesterol level of 319 mg/dL (8.3 mmol/L) [recommended normal range is 70-100 mg/dL (1.8-2.6 mmol/L)]. All patients underwent carotid artery ultrasound to find the amount of blockage in the arteries at the beginning and the end of the study.

At the beginning of the study, there was no difference in the carotid artery thickness between the two groups. After two years, there was no improvement and no difference between the Vytorin and simvistatin groups. However, the LDL cholesterol was significantly lower in the Vytorin group which is promising. The Vytorin group saw a 58% reduction in LDL compared to 41% reduction in the simvistatin group after 2 years.

How Does This Affect You?

Lowering your cholesterol is very important. If your physician has recommended ezetimibe, continue taking it. You should not make any decisions based on this study. The patients in this study are a special group with very severe cholesterol levels. Also, the outcome of this study was simply the ultrasound result. This result is important for research but does not tell us how the medication helps individual patients. There have not been any studies that show ezetimibe prevents heart attacks, strokes, or death. While this recent report is discouraging news, there are many studies that show ezetimibe reduces cholesterol especially when combined with other cholesterol-lowering medications. Remember that exercise and healthy diet are still very important first steps to reduce your cholesterol.




Last reviewed February 2008 by Larissa J. Lucas, MD

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