Corporate Banner
Satellite Banner
Genotyping & Gene Expression
Scientific Community
Become a Member | Sign in
Home>News>This Article

FDA Announces New Warning on Plavix: Avoid Use with Prilosec/Prilosec OTC

Published: Wednesday, November 25, 2009
Last Updated: Wednesday, November 25, 2009
Bookmark and Share
Patients should avoid using the stomach acid reducer Prilosec/Prilosec OTC (omeprazole) with the anti-clotting drug Plavix (clopidogrel), the U.S. Food and Drug Administration warned on Nov. 17. New data suggest that when patients take both Prilosec and Plavix, Plavix’s ability to block platelet aggregation (anti-clotting effect) may be reduced by about half. “Both of these drugs, when used properly, provide significant benefits to patients.” said Mary Ross Southworth, Pharm.D., of the Div

New data suggest that when patients take both Prilosec and Plavix, Plavix’s ability to block platelet aggregation (anti-clotting effect) may be reduced by about half.

“Both of these drugs, when used properly, provide significant benefits to patients.” said Mary Ross Southworth, Pharm.D., of the Division of Cardiovascular and Renal Products in the FDA’s Center for Drug Evaluation and Research. “However, patients at risk for heart attacks or strokes who use Plavix to prevent platelet aggregation will not get the full effect of this medicine if they are also taking Prilosec.”

Plavix is used to prevent blood clots that could lead to heart attacks or strokes in at-risk patients. Omeprazole, the active ingredient of Prilosec and Prilosec OTC, is a proton pump inhibitor (PPI) used to reduce the production of stomach acid and prevent stomach irritation.

Plavix does not have anti-clotting effects until it is converted or metabolized into its active form with the help of the liver enzyme, CYP2C19. Prilosec blocks this enzyme, thereby reducing the effectiveness of Plavix.

After issuing an Early Communication in January about possible drug interactions involving Plavix, the FDA requested new studies from the drug’s manufacturers, sanofi-aventis and Bristol-Myers-Squibb. These new studies support the existence of a significant interaction that could negatively impact a person’s health. Based on the current scientific information, the Plavix label has been updated with new warnings about the use of Prilosec and other drugs that inhibit the CYP2C19 enzyme and that could interact with Plavix in the same way.

The new studies compared people who took Plavix and Prilosec together with people who took Plavix alone. A reduction in Plavix’s anti-clotting effect was found in those individuals who took the combination. Similar results were seen irrespective of whether the two drugs were taken at the same or different times of day.

It is unknown how other PPIs may interfere with Plavix. Other drugs that should not be used with Plavix because they may have a similar interaction with CYP2C19 include Nexium (esomeprazole), Tagamet and Tagamet HB (cimetidine), Diflucan (fluconazole), Nizoral (ketoconazole), VFEND (voriconazole), Intelence (etravirine), Felbatol (felbamate), Prozac, Serafem, Symbyax (fluoxetine), Luvox (fluvoxamine) and Ticlid (ticlopidine).

Patients who take Plavix and need to take a drug to reduce stomach acid should discuss their therapy with a health care professional. Zantac (ranitidine), Pepcid (famotidine), Axid (nizatidine), and antacids do not inhibit the CYP2C19 enzyme and aren’t expected to interfere with the anti-clotting activity of Plavix.

Plavix’s manufacturers have agreed to continue conducting studies to explore this and other drug interactions. When the FDA has reviewed additional data, the agency will communicate any new recommendations or conclusions.

FDA Public Health Advisory:

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,800+ scientific posters on ePosters
  • More than 4,000+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Confusion as FDA Classify Genome Interpretation as Medical Test
FDA conclude deciphering your genome should therefore be subject to approval by the appropriate regulatory bodies
Monday, November 28, 2011
Scientific News
Ancient Viral Molecules Essential for Human Development
Genetic material from ancient viral infections is critical to human development, according to researchers at the Stanford University School of Medicine.
Measuring microRNAs in Blood to Speed Cancer Detection
A simple, ultrasensitive microRNA sensor holds promise for the design of new diagnostic strategies and, potentially, for the prognosis and treatment of pancreatic and other cancers.
Personalized Drug Screening for Multiple Myeloma Patients
A personalized method for testing the effectiveness of drugs that treat multiple myeloma may predict quickly and more accurately the best treatments for individual patients with the bone marrow cancer.
Metabolic Profiles Distinguish Early Stage Ovarian Cancer with Unprecedented Accuracy
Studying blood serum compounds of different molecular weights has led scientists to a set of biomarkers that may enable development of a highly accurate screening test for early-stage ovarian cancer.
New Way to Force Stem Cells to Become Bone Cells
Potential therapies based on this discovery could help people heal bone injuries or set hardware, such as replacement knees and hips.
Promise of Newborn Stem Cells to Revolutionize Clinical Practice
In this article Shweta Sharma, PhD, discusses the potential of an Umbilical Cord Blood bank as an untapped source of samples for research and clinical trials.
New Anti-Malarial Drug Screening Model
University of South Florida researchers demonstrate novel chemogenomic profiling to identify drug targets for the most lethal strain of malaria.
Coronavirus Breakthrough
Protein mutation affects spread and virulence of respiratory virus.
New, Better Test for Prostate Cancer
A study from Karolinska Institutet shows that a new test for prostate cancer is better at detecting aggressive cancer than PSA.
Circadian Clock Controls Insulin and Blood Sugar in Pancreas
Map of thousands of genes suggests new therapeutic targets for diabetes.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos