PPIs & Plavix Together May Increase Risk of Heart Attack
The research, which took place over six years, involved more than 16,000 heart attack patients aged 66 years and older who were started on the blood-thinning drug clopidogrel. Scientists found that patients' risk for readmission to hospital for another heart attack was significantly higher if they were taking omeprazole (Prilosec), lansoprazole (Prevacid), and rabeprazole (Aciphex). The investigators found no such increased risk for patients taking the PPI drug pantoprazole, or among those taking other acid-lowering medications called H2 receptor antagonists (also known as H2 blockers).
Previous research suggests that, with the exception of pantoprazole (Protonix), PPIs can inhibit the liver's ability to convert clopidogrel to its active form, a necessary step required for clopidogrel to be effective.
Most patients treated with clopidogrel also receive aspirin (acetylsalicylic acid -- ASA) to prevent another heart attack, but ASA can cause bleeding from the stomach. Recent guidelines from the American Heart Association, the American College of Gastroenterology, and the American College of Cardiology recommend that all patients aged 60 years or older who are receiving ASA also be treated with a PPI to reduce the risk of bleeding. Dr. Juurlink, head of the Division of Clinical Pharmacology and Toxicology at Sunnybrook Health Sciences Centre in Toronto and the study's lead author, states, "Depending on which PPI is prescribed, the effectiveness of clopidogrel in preventing recurrent myocardial infarction may be reduced or eliminated altogether."
Dr. Juurlink adds that doctors should be selective in what PPI is prescribed for patients who are receiving clopidogrel.
The article, entitled "A Population-Based Study of the Drug Interaction Between Proton Pump Inhibitors and Clopidogrel," will appear in the March 31, 2009 print version of the Canadian Medical Association Journal.
Comments
I am very concerned. In Jan. 2007 I had my first heart attack. At this time my cardiologist started me on plavix and omeprazole. In Oct 2007 I suffered heart failure, my Doctor continued my regiment of plavix and omeprazole. About a week ago I was notified by my Cardio office that my prescription for omeprazole was being discontinued due to an adverse interaction with plavix. I was advised not to take the balance of my pres. of omeprazole but to start immediately on a new pres. for Ranitidine.