March 12, 2010 9:29 PM

FDA: Some Patients Cannot Process Plavix

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CBSNews
(AP)  The Food and Drug Administration is adding its strongest warning to the label for Plavix, cautioning that some patients do not respond to the blockbuster blood thinner.

The FDA said in a statement Friday that certain patients with a genetic variation cannot metabolize the drug, putting them at increased risk for heart attack and stroke.

Patients can determine if they are "poor metabolizers" by taking a genetic test. The FDA recommends these patients use other blood thinners, such as aspirin.

The FDA added similar language to Plavix's label in November, but the new warning appears within a black box, the FDA's most severe safety labeling.

Plavix is prescribed to heart disease patients to prevent dangerous blood clots, which can cause heart attack, stroke and death.

With genetic tests costing around $500, experts say it's unlikely such testing will become standard for patients taking Plavix.

"I think based on this people will do more genetic testing, but I think it's premature to say that everyone who gets Plavix needs to be tested," said Dr. Louis Teichholz, head of cardiology at Hackensack University Medical Center.

Teichholz said the black box warning on Plavix could push more doctors to prescribe Effient, a competing blood thinner launched by Eli Lilly & Co. last summer.

In order to work effectively, Plavix must be broken down by a particular liver enzyme. But FDA says 2 to 14 percent of people in the U.S. have low levels of the enzyme, preventing them from successfully processing Plavix. The likelihood of being a non-responder varies by race, according to the FDA.

According to Sanofi-Aventis and Bristol-Myers Squibb, which market the drug, the patients who are designated as poor metabolizers represent about 2 percent of whites, 4 percent of blacks and 14 percent of Chinese, according to the prescribing information. In total, poor metabolizers account for 3 percent of the population, the companies said.

"Patients should not stop taking Plavix unless told to do so by their health care professional," the agency said in an online statement. "They should talk with their health care professional if they have any concerns about Plavix, or to find out if they should be tested for being a poor metabolizer."

Using a higher dose of Plavix can increase blood thinning in non-responsive patients, according to the new label, though higher doses have not been cleared by the FDA.

Plavix, with global sales of $8.6 billion in 2008, was the world's second-best selling drug behind Pfizer's cholesterol drug Lipitor.

A spokeswoman for New York-based Bristol-Myers said the company would add the new labeling to bottles of Plavix over the next two months.

"The revisions to the prescribing information for Plavix reflect the companies' ongoing research in collaboration with the FDA," said Laura Hortas.

In November, the FDA warned that taking stomach-soothing drugs like Prilosec and Nexium alongside Plavix could cut the blood-thinner's effect in half. Regulators said the key ingredient in the heartburn medications blocks the same liver enzyme needed to break down Plavix, muting the drug's full effect.

Shares of Bristol-Myers Squibb Co. fell 7 cents to $25.89. Shares of Sanofi-Aventis fell 15 cents to $38.04.

AP
Add a Comment
by Fatesrider March 13, 2010 2:36 AM EST
How about we stop advertising for things that not everyone can just go up and buy?

Liquor: There may be a bit of the Captain in Everyone, but none of that crap ever happens. Drinking any brand of beer will NOT make YOU look any better to someone else. Usually, it's the opposite. I call it false advertising, but seriously, do we NEED to advertise and promote drunkenness?

Prescription drugs: If you can't buy it legally over the counter, you shouldn't be advertising it. After all, how many of the prescription drugs advertised in the last few years have been deemed unsafe? 5? 10? All of them? How about we let them run under the advertising radar until we know whether taking them will kill us, THEN allow limited advertising - assuming we even need to spend the money to hire advertisers at all.

So as far as I'm concerned, anything that you can't just walk into a store and buy over the counter without some form of official permission (age or prescription) should not be allowed to be advertised.
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by cyberus-2009 March 13, 2010 12:46 PM EST
Nice idea, too bad the pharma-corps own too many congresscritters for something like that to happen.
by estabwary March 12, 2010 9:27 PM EST
What's cheaper? $500 or a heart attack? Keep in mind that these results come off the backs of many others who suffered for being lab rats long before this. Now they want to tell 3% of us we aren't worth a $500 test to prevent a heart attack. Wake Up People.
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by baileyccc March 12, 2010 9:03 PM EST
Gee a synthetic poison that they call a drug which is laced with side effects can not be tolerated by some people. What a shock, good work FDA. posted by baileyccc
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