Plavix is a medication used to prevent blood clots that are usually caused after a heart attack or stroke by keeping blood platelets from sticking together to cause clots. According to the new reviews published in the American Medical Association said that the genetic test is not of any use for patients that are more at a risk for heart attack and other cardiac complications.

Plavix is one of the world’s bets selling and the most preferred medication, Plavix medication is marketed by US-based Bristol-Myers Squibb and France’s Sanofi.

In 2010, the USFDA (Food and Drug Administration) passed on a order to the Plavix manufacturers to add a boxes warning on the Plavix packets mentioning that  the medication may be less effective in averting heart attacks  in people  who cannot metabolize the pill completely

The FDA said an estimated two to 14 percent of the US populations are poor metabolizers who have a certain variant of the gene that makes the CYP2C19 liver enzyme, which converts Plavix to its active form.

The FDA had recommended that doctors prescribe higher doses of Plavix, or clopidogrel, to those patients who had the genetic test and were found not to produce enough of the enzyme.

“The FDA’s warnings on Plavix were premature and were not based on solid science,” said Steven Nissen, a cardiologist at the Cleveland Clinic Foundation, in an editorial published in the Journal of the AMA.

Plavix sales totalled $5.4 billion in the first three quarters of 2011, as compared with $4.9 billion in the same period last year.

About 40 million people take the drug worldwide.