The Food and Drug Administration after a year of review said they supported the use of the controversial cholesterol-lowering drug Vytorin and said no significant difference in carotid artery thickness was seen in patients taking Vytorin as compared to patients taking the drug Zocor.

The agency also reported that a decrease of 56 % was seen in the levels of bad cholesterol (LDL) in the Vytorin group compared to 39 % for the Zocor group. "Following two years of treatment," the statement said, "carotid artery thickness increased by 0.011 mm (millimeters) in the Vytorin group and by 0.006 mm in the simvastatin group. The difference in the changes in carotid artery thickness between the two groups was not statistically significant. However . . . the difference in the reductions in LDL cholesterol between the two groups was statistically significant." Measuring the thickness of the carotid arteries in the neck through ultrasound imaging is considered a biomarker of risk for cardiovascular disease, the agency said.

The debate began after initial results of a study called ENHANCE indicated that Vytorin was no better than Zocor at reducing plaque buildup in neck arteries and that the drug Zetia showed no added benefit over Zocor. This resulted in doctor’s switching to the older drugs and sales of both Vytorin and Zetia began falling.

The FDA after it’s year-long review of the final clinical study report of the Enhance trial issued a statement to say that "elevated amounts of low-density lipoprotein (LDL) . . . are a risk factor for cardiovascular diseases such as heart attack, stroke and sudden death, and that lowering LDL cholesterol reduces the risk of these diseases."

Dr. Valentin Fuster, former American Heart Association President, now director of the Mount Sinai Heart Center in New York said, "What the FDA is saying is exactly the way I'm practicing."

The drug Vytorin, sold by a joint venture of Merck, based in Whitehouse Station, N.J., and Schering-Plough, based in Kenilworth, N.J., is a combination pill of Schering-Plough's Zetia, which reduces the amount of cholesterol absorbed from food, and Merck's former blockbuster Zocor, which lowers the amount of cholesterol produced by the body based on one's genes. As generic versions were launched in June 2006 which cost one third of Vytorin, the competition stepped up. "The price differential between the two products is so big that this may not make much of a difference" in sales of Vytorin and Zetia, given the recession, said analyst Steve Brozak of WBB Securities.

In its statement, the FDA wrote that, "Based on currently available data, patients should not stop taking Vytorin or other cholesterol-lowering drugs and should talk to their doctor or other health care professional if they have any questions."

"We are pleased that the agency has completed its review of the ENHANCE study," the companies said.