A new study, presented at the American Heart Association scientific meeting in Orlando, Florida, has raised fresh concerns about the effectiveness as well as safety of the cholesterol-lowering Merck drug 'Zetia.'

The study, published on the Internet by the New England Journal of Medicine, delivered yet another blow to the already-tainted Merck cholesterol franchise; and noted that the Abbot drug 'Niaspan' was apparently more effective and safe as a supplementary cholesterol treatment to statins.

For the 14-month study, led by Dr. Alan Taylor, the researchers observed 363 heart patients or high-risk people - most of them from Walter Reed Army Medical Center - who had been taking statins, like Lipitor and Crestor, for nearly six years on average.

Half of the study participants were administered Niaspan and the remaining were treated with Zetia. After 14 months, the researchers noted that while there were only two heart attacks, heart- related deaths or other heart-related problems in the people who received Niaspan, there were nine such cases in the Zetia group.

Furthermore, ultrasound images of neck arteries revealed that Niaspan brought about a 2 percent reduction in buildups, while Zetia had no effect on the buildups, even though it met with the expectations pertaining to the lowering of the bad cholesterol.

About the apparent lack of effectiveness of Zetia, Taylor said: "It should be better for the arteries and it wasn't!"