Plavix, with global sales of $8.6 billion in 2008, was the world's second-best selling drug behind Pfizer's cholesterol drug Lipitor. For more than 11 years, doctors have written Plavix prescriptions to over 100 million people. Plavix has been the focus of extensive research, studies, and scientific findings. The effectiveness of Plavix has been proven and the safety profile supported by 4 large clinical studies involving 81,000 patients. (PLAVIX Website). It is recommended for people with Acute Coronary Syndrome, post heart attacks, unstable angina, recent strokes, Peripheral Artery Disease and post heart and carotid stent placements. Once again, the popular but controversial drug is under scrutiny. Unfortunately this it not the first time.
Easy on the Stomach
Plavix was recommended by medical groups as an easy-on-the-stomach substitute for aspirin. A study published in January of 2005, in the New England Journal of Medicine, showed otherwise. The published data demonstrated that patients on Plavix experienced 13 times as many ulcers as those on Aspirin. That study caused concern for tens of thousands of Americans who must take anti-clotting drugs for their hearts but are also prone to gastrointestinal problems. The company responded with a contraindication statement within its' prescribing literature. It could no longer be considered safer than aspirin on the stomach.
Protonex or Nexium will protect the stomach
Physicians considered the options and many who prescribed Plavix to patients at risk for gastrointestinal problems found a solution. They thought that prescribing an additional medication called a proton pump inhibitor (Protonix, Nexium), would protect the stomach while still providing the benefits of Plavix. Not so fast! In a study presented at the American Heart Association meeting in November 2008, showed the risk of heart attack or other cardiac trouble to be 50 percent higher in patients taking the combination of Plavix and a heartburn med than in those taking Plavix alone. There were two additional studies with similar findings that year as well. Those studies helped to answer the questions on the minds of physicians and researchers following publication of a 2003 study in the journal Circulation by Paul Gurbel. Gurbel, a cardiologist at Sinai Hospital in Baltimore, found that nearly 30 percent of patients did not process Plavix effectively, but the reasons for that were unclear. Researchers theorized that the PPIs might interfere with a liver enzyme needed to metabolize the clot-buster. The theory regarding the liver enzyme has now been proven.
Liver Enzyme
In order to work effectively, Plavix must be broken down by a certain liver enzyme (CYP2C19). The FDA says up to 14 percent of people in the U.S. have low levels of this enzyme, preventing them from processing Plavix effectively. Apparently being a non-responder varies by race. According to Sanofi-Aventis and Bristol-Myers Squibb, which market the drug, the patients who are designated as "poor metabolizers" represent 2 percent of whites, 4 percent of blacks and 14 percent of the Chinese population.
"Patients should not stop taking Plavix unless told to do so by their health care professional," the agency said in an online statement. "They should talk with their health care professional if they have any concerns about Plavix, or to find out if they should be tested for being a poor metabolizer." With genetic tests costing nearly $500, experts say it's unlikely such testing will become standard for patients taking Plavix.
Read part two for company response, alternatives and educational opportunities. Part Two
Plavix plus heartburn meds article
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