Volume 1, Issue 14, 04/21/2009
What is the mechanism by which the proton pump inhibitor, omeprazole (Prilosec®), reduces the antiplatelet effects of clopidogrel (Plavix®) thereby decreasing its cardioprotective effects?
The use of antiplatelet therapies (in particular aspirin and clopidogrel (Plavix®)) are increasing due to their proven benefits in both primary and secondary prevention of cardiovascular disease (CVD).(1,2) While each of these agents can be used as monotherapy for a number of CV related conditions, their use together is also very common, especially in those receiving drug eluting stents.(3) Unfortunately, the combination of aspirin and clopidogrel may increase the patient's risk for clinically relevant gastrointestinal (GI) bleeding.(4) Recognizing the potential for this adverse event has become increasingly important since the publication of a position statement sponsored by the American Heart Association stating that patients receiving drug eluting stents should receive at least 12 months of aspirin and clopidogrel therapy.(3) Due to the benefits of combination antiplatelet therapy in the setting of drug eluting stent placement and recognizing the increased risk for GI bleeding, the American College of Cardiology Foundation (ACCF), in collaboration with the AHA and American College of Gastroenterology, published an Expert Consensus Document in 2008 that recommends the addition of a proton pump inhibitor (PPI) as the preferred class of agents for the treatment and prophylaxis against aspirin-associated GI injury.(4) One of the most commonly used PPIs on the market, which is also available over-the-counter (OTC), is omeprazole (Prilosec®). Unfortunately, several recent studies have suggested that patients taking clopidogrel who also take omeprazole experience a greater number of CV events.(5-8) What is the mechanism by which omeprazole decreases the antiplatelet effect of clopidogrel?......To read the full answer please LOGIN or SUBSCRIBE NOW.
