Plavix (clopidogrel) is an important anti-platelet drug that is used extensively to help prevent blood clotting (thrombosis) in patients with coronary artery disease. Plavix is most often used in treating acute coronary syndrome (ACS), which encompasses conditions like acute heart attack and unstable angina, and after the placement of stents in order to prevent stent thrombosis. Plavix is the second most-prescribed drug in the United States.
Plavix often causes heartburn symptoms, so PPIs have been prescribed commonly in people taking this drug. In fact, guidelines published by several professional societies actually recommend PPIs in patients taking Plavix, in order to prevent gastrointestinal ulcers that may be particularly prone to bleeding in people on anti-platelet drugs. PPIs available by prescription include Prilosec and Zegerid (omepromazole), Prevacid (lansoprazole), Protonix (pantoprazole), Aciphex (rabeprazole), and Nexium (esomeprazole). Prilosec is also sold over-the-counter for heartburn.
A little more than a year ago, evidence emerged that commonly-used proton-pump inhibitors might significantly reduce the effectiveness of Plavix in patients with coronary arteyr disease. At that time, in a retrospective study of 8205 patients with ACS, those who were discharged on both Plavix and a PPI had a 25% increased risk of death or rehospitalization for recurrent ACS than patients treated with Plavix alone.
And last week, at the Scientific Sessions of the Society for Cardiovascular Angiography and Interventions (SCAI), the largest study yet (over 16,000 patients) again suggested that using PPIs may pose a problem for patients with coronary artery disease who are taking Plavix. In this study, the risk of developing major cardiovascular events (such as heart attacks) was significantly higher for those also taking Prilosec, Zegerid, Nexium, Protonix, or Prevacid. (Too few patients were taking Aciphex in this study to reach any conclusions about that particular PPI.)
So far, all the studies correlating the use of PPIs with a reduced effectiveness of Plavix are retrospective and observational, and so cannot prove a cause-and-effect relationship. However, the evidence is now strong enough that the SCAI has just revised its recommendations. This organization now recommends that physicians avoid prescribing PPIs in patinets taking Plavix unless it is considered very necessary, and instead, whenever possible, use alternative medications for treating gastrointestinal symptoms, such as histaminergic (H2) blockers like Zantac or Tagamet, or antacids.
If you are taking Plavix for any reason, you should discuss this issue with your doctor before agreeing to take any of the PPIs by prescription, or over-the-counter.