In January 2009, the FDA announced that it is working with the makers of clopidogrel (Plavix) to study how genetic factors and other drugs (especially the proton pump inhibitors (PPIs)) may alter the effectiveness of clopidogrel, the active ingredient in Plavix. PPIs include deslansoprazole (Kapidex), esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec, Prilosec OTC), pantoprazole (Protonix), and rabeprazole (Aciphex). This FDA action was prompted by recent reports suggesting clopidogrel does not work as well in some patients as it does in others. Differences in effectiveness may be due to changes in the way the body breaks down clopidogrel.
In November 2009, the FDA announced there is new data showing that the PPI heartburn medicine omeprazole (Prilosec, Prilosec OTC) reduces the anti-blood clotting effect of clopidogrel (Plavix) by almost half when these two medications are taken by the same patient. Patients who use clopidogrel to prevent blood clots and reduce the risk for heart attacks or strokes will not get the full benefit of this medicine if they are also taking omeprazole. Esomeprazole (Nexium) may also interact with clopidogrel in the same way. The FDA is recommending that omeprazole and esomeprazole be avoided in combination with clopidogrel. At this time, it is unknown to what extent other proton pump inhibitor (PPI) heartburn medicines like pantoprazole (Protonix) may interfere with clopidogrel. When more information becomes available, the FDA will communicate any additional recommendations or conclusions on the use of clopidogrel.
Since clopidogrel can cause bleeding in the stomach, proton pump inhibitors like pantoprazole (Protonix) have been previously used in combination to reduce the production of stomach acid, and prevent stomach bleeding. If you are taking pantoprazole and clopidogrel, you may want to follow up with your doctor to discuss your need for continuing pantoprazole. If you need a medication to reduce stomach acid, you can ask your doctor about antacids (such as Maalox or Mylanta) or other acid reducers, such as ranitidine (Zantac), famotidine (Pepcid), or nizatidine (Axid). The FDA does not believe that these medicines will interfere with the anti-clotting activity of clopidogrel.