Use of a proton pump inhibitor (PPI) to protect against gastrointestinal (GI) bleeding in patients taking the antiplatelet agent clopidogrel (Plavix) may interfere with the activation of clopidogrel and diminish its antiplatelet effect, increasing the risk of cardiovascular events.1 A randomized, placebo-controlled trial (COGENT) has found that use of the PPI omeprazole in patients taking clopidogrel in addition to aspirin decreased the incidence of GI bleeding without increasing the risk of a cardiovascular event, but the number of cardiovascular events was small and the formulation of...

Clopidogrel (Plavix - Sanofi-Aventis and Bristol-Myers Squibb), an oral thienopyridine that inhibits platelet aggregation, is now being advertised directly to the public on television. Clopidogrel is approved by the FDA for secondary prevention of myocardial infarction (MI), stroke and other vascular events and for use in patients with acute coronary syndrome (unstable angina or non-ST-elevation MI), including those undergoing angioplasty. It is used off-label for patients with ST-elevation acute MI

Clopidogrel (Plavix), which prevents arterial thrombosis by inhibiting platelet activation, is commonly prescribed (usually with aspirin) for months after acute coronary syndromes and stent implantation. It may also, however, increase the risk of bleeding. Therefore, a proton pump inhibitor (PPI) such as omeprazole (Prilosec, and others) is often given concurrently to decrease the risk of gastrointestinal (GI) bleeding. Some reports have suggested that omeprazole may interfere with the antiplatelet effect of clopidogrel.

The antiplatelet drug clopidogrel (Plavix, and others) reduces major cardiovascular events, but can cause bleeding. Proton pump inhibitors (PPIs) are often used with clopidogrel to prevent gastrointestinal bleeding, however, some evidence suggests that PPIs may interfere with the activation of clopidogrel and diminish its antiplatelet effect. FDA-approved labeling recommends avoiding concurrent use of the PPIs omeprazole and esomeprazole with clopidogrel.

Clopidogrel bisulfate (Plavix - Bristol-Myers Squibb/Sanofi), a new thienopyridine antiplatelet agent similar to ticlopidine (Ticlid - Medical Letter, 34:65, 1992), has been approved by the US Food and Drug Administration (FDA) for secondary prevention of myocardial infarction, stroke and other vascular events.

Current guidelines recommend use of a proton pump inhibitor (PPI) to decrease the risk of gastrointestinal bleeding in patients taking clopidogrel (Plavix) with aspirin. A recent issue of The Medical Letter considered whether omeprazole (Prilosec, and others) or other PPIs could interfere with the antiplatelet effect of clopidogrel. The conclusion was that patients taking both drugs should probably continue to do so until more data became available. Several new publications require reconsideration of that recommendation.

The FDA has required the manufacturer of Plavix, an antiplatelet drug used in addition to aspirin to prevent cardiovascular events in high-risk patients,1 to add a boxed warning to the package insert about the risk of a poor response to the drug in patients with genetic polymorphisms of the cytochrome P450 enzyme CYP2C19. Clopidogrel is a prodrug and CYP2C19 is mainly responsible for its bioactivation. The Medical Letter reported last year that several studies have found higher rates of cardiovascular events, including stent thrombosis, in patients with these polymorphisms taking...

The FDA has approved prasugrel (Effient - Lilly/Daiichi Sankyo), an oral antiplatelet drug, for use with aspirin to reduce the rate of thrombotic cardiovascular events in patients with acute coronary syndromes (ACS) being managed with percutaneous coronary intervention (PCI). It will compete with clopidogrel (Plavix) for such use.

The FDA has approved ticagrelor (Brilinta – AstraZeneca), an oral antiplatelet drug, for use with low-dose aspirin to reduce the rate of thrombotic cardiovascular events in patients with acute coronary syndrome (ACS). It will compete with clopidogrel (Plavix) and prasugrel (Effient) for such use. Clopidogrel is expected to become available generically in the US within the next few months.

The antiplatelet agents aspirin and clopidogrel (Plavix, and others) are used in most patients undergoing percutaneous coronary intervention (PCI) to prevent stent thrombosis and to reduce the occurrence of peri-, post-procedural and late cardiovascular events. Despite a large number of randomized trials of these agents in such patients, the optimal dosage and duration of treatment with these drugs, and whether other drugs should be added, is unclear.