The US FDA has declared that Vytorin manufactured by Merck & Co Inc. and Schering-Plough should be used as combination drug. The FDA had conducted a study on the controversial drug before coming to the conclusion.

Vytorin, is a costly drug which is administered as a combination drug. The drug helps in reducing the harmful cholesterol. However, the previous drugs that were used for the same purpose costed about one third of Vytorin.

However, the FDA said that after the completion of its review it has found that the use of drug for two years showed no difference in the in the thickness of carotid artery walls but it did show a significant decrease in the cholesterol levels.

According to the FDA, Vytorin had the capability to reduce the level of bad, or LDL cholesterol by 56 percent, whereas Zocor led to a reduction of a 39 percent.

It has been demonstrated that patients who reduce their LDL can reduce their risk of heart attacks and stroke. The FDA has used the plea in allowing the use of Vytorin.

"Based on current available data, patients should not stop taking Vytorin or other cholesterol lowering medications and should talk to their doctor if they have any questions about Vytorin, Zetia, or the Enhance trial," the FDA said.