Posted on 08/26/2009 10:17:38 PM PDT by neverdem
Contact: Alisa Zapp Machalek
alisa.machalek@nih.gov
301-496-7301
NIH/National Institute of General Medical Sciences
WHAT: A new study reports that a gene variant carried by about a third of the population plays a major role in this group's response to an anti-clotting medicine, clopidogrel (Plavix). People with the variant produce a defective version of the CYP2C19 enzyme and are less able to activate the drug.
One of the world's best-selling medicines, Plavix prevents blood clots in people with heart disease by keeping platelets from sticking together. But about 30 percent of people respond poorly to the drug and are at increased risk for dangerous events like strokes and heart attacks.
By performing a sophisticated method called a genome-wide association study in two distinct populations, Pennsylvania Amish and residents of urban Baltimore, the researchers found that a common variant of the CYP2C19 gene is a key determinant of how people respond to Plavix. The CYP2C19 enzyme chemically modifies the drug inside the body, converting it to the active form.
ARTICLE: "Association of Cytochrome P450 2C19 Genotype with the Antiplatelet Effect and Clinical Efficacy of Clopidogrel Therapy" by Alan R. Shuldiner, Jeffrey R. O'Connell, Kevin P. Bliden, et. al. The paper will appear in the August 26, 2009, issue of the Journal of the American Medical Association.
SPOKESPERSON: Rochelle M. Long, Ph.D., director of the National Institutes of Health Pharmacogenetics Research Network, is available to comment on this work and its importance to the field of pharmacogenetics.
CONTACT: To schedule an interview, contact Alisa Machalek in the NIGMS Office of Communications and Public Liaison at 301-496-7301 or alisa.machalek@nih.gov
More information on the Pharmacogenetics Research Network is available at http://www.nigms.nih.gov/Initiatives/PGRN/
NIGMS is a part of NIH that supports basic research to increase our understanding of life processes and lay the foundation for advances in disease diagnosis, treatment, and prevention. For more information on the Institute's research and training programs, see http://www.nigms.nih.gov.
The National Institutes of Health (NIH) — The Nation's Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary Federal agency for conducting and supporting basic, clinical, and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.
The loss-of-function CYP2C19*2 genotype is common in diverse populations. In white populations, approximately 24% have at least 1 CYP2C19*2 allele. The frequency of this allele is somewhat lower in Mexican Americans ( 18% with at least 1 CYP2C19*2 allele), higher in African Americans ( 33% with at least 1 copy), and markedly higher in Asian populations ( 51% with at least 1 copy).36-38 Thus, clopidogrel resistance due to this variant may be particularly important in Asian and African American populations. However, the strength of effect of CYP2C19*2 genotype on clopidogrel response may depend on other factors such as genetic background or environmental exposures, which may differ among ethnic groups. Unfortunately, our sample size was not sufficient to examine ethnicity-specific differences in CYP2C19 genotype effects on clopidogrel response. Additional studies in diverse populations will be necessary.
The commonly prescribed proton pump inhibitors omeprazole and esomeprazole, and some other medications commonly coprescribed with clopidogrel, such as cimetidine and fluoxitine, are potent inhibitors of CYP2C19, introducing the possibility that they may attenuate the antiplatelet activity of clopidogrel, especially in individuals heterozygous or homozygous for the CYP2C19*2 genotype.14, 39-41 We could not test this hypothesis directly, because all participants in the Amish PAPI Study were drug-naive, and the number of participants taking proton pump inhibitors in the Sinai Hospital of Baltimore sample was too small.
We never recommend PPIs to heart patients/those on cholestrol meds. There are plenty of natural products that work great without shutting off the acid completely.
It has been a very high allergy season here in Northern NV therefore, patients coming in with all kinds of symptoms including high acid causing esophageal problems. You may want to look into that cause. And also consider your pH level. (We encourage all our patients to know their pH level as a more alkaline pH means a better working body ;)
If you think you may have acid/pH issues...find some strips to measure your pH through your urine. Vaxa has some good strips available.
For digestive and 'fire' issues....there is a product called Pitta Digest by Banyan Botanicals that we have had great success with for those with 'fire' in their bellies ;) If you think you are in need of digestive enzymes, MRM's Digest-All is fantastic! If you try an allergy product....over the counter allergy products will result in your pH to go very acidic so an herbal product for allergies to help with the histamine reaction would be a better choice. Vaxa has come out with a great allergy and sinus product you may want to check into. Also...a good standby for allergies is Ortho Molecular's D-Hist.
I hope this information helps!
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