Your Health

FDA Says Don't Mix Plavix And Prilosec

If you're taking Plavix to prevent a heart attack or stroke, lay off the Prilosec, the Food and Drug Administration says.

Prilosec can reduce Plavix's effectiveness. i

Taking Prilosec with Plavix can reduct the effectiveness of the clot-fighter. Al Behrman/AP hide caption

itoggle caption Al Behrman/AP
Prilosec can reduce Plavix's effectiveness.

Taking Prilosec with Plavix can reduct the effectiveness of the clot-fighter.

Al Behrman/AP

It turns out that the popular heartburn pill Prilosec cuts the effectiveness of Plavix, an anticlotting medicine that's been taken by more than 90 million people. That can raise the risk for heart attacks and strokes in patients taking Plavix. Prilosec is also sold without a prescription as Prilosec OTC.

How? Prilosec, or omepazole, inhibits an enzyme called CYP2C19 that transforms the main ingredient in Plavix to make it work inside the body. Same goes for Nexium, the son of Prilosec, which has the same effect.

FDA recommends that people on Plavix who also need something to fight heartburn take a different kind of medicine to reduce stomach acid, such as Maalox, Zantac or Pepcid.

One caveat: don't substitute Tagamet, which also seems to interfere with the critical enzyme and could reduce Plavix's effectiveness. Indeed, the FDA says a bunch of other medicines, antifungal Diflucan and antidepressant Prozac.

Prilosec and Nexium belong to a class of heartburn drugs called proton pump inhibitors, which also includes such big sellers as Prevacid and Protonix.

About 1 in 20 Americans takes a PPI. So reporters asked FDA if the advice applies to all the PPI drugs. FDA's Mary Ross Southworth said the agency "doesn't have enough information on other members of the class to make the recommendation" against use with Plavix, except for Nexium.

The FDA said its decision was based on data submitted this summer by Sanofi-Aventis, maker of Plavix, as part of a review the agency announced early this year.

Several previous studies suggested PPIs might interfere with Plavix, including one by pharmacy benefits manager Medco in 2008 and another sponsored by the Veterans Administration published in JAMA in March.



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