Featured Research

from universities, journals, and other organizations

Analysis does not support genetic test before use of anti-clotting drug

Date:
December 27, 2011
Source:
JAMA and Archives Journals
Summary:
Although the US Food and Drug Administration (FDA) has recommended that a certain type of genetic testing (for the genotype CYP2C19) be considered before prescribing the drug clopidogrel to identify individuals who may be less responsive to the medication, a review and analysis of previous studies did not find an overall significant association between the CYP2C19 genotype and cardiovascular events.

Although the U.S. Food and Drug Administration (FDA) has recommended that a certain type of genetic testing (for the genotype CYP2C19) be considered before prescribing the drug clopidogrel to identify individuals who may be less responsive to the medication, a review and analysis of previous studies did not find an overall significant association between the CYP2C19 genotype and cardiovascular events, according to a study in the December 28 issue of JAMA.

Related Articles


Clopidogrel is an antiplatelet drug used by approximately 40 million patients worldwide to treat or prevent atherothrombotic (blood clot from thickening of inner lining of arteries) events and after percutaneous coronary revascularization (such as balloon angioplasty). "Despite the overall benefit, some individuals may be less responsive to clopidogrel than others because clopidogrel is a prodrug activated by several enzymes, including CYP2C19, and common genetic variation in CYP2C19 alters enzyme activity," according to background information in the article. The American Heart Association and American College of Cardiologists have argued evidence is insufficient to support CYP2C19 genotype testing.

Michael V. Holmes, M.B.B.S., M.Sc., of University College London, and colleagues conducted a systematic review and meta-analysis to assess the strength and quality of evidence on the association of CYP2C19 genotype with responsiveness to clopidogrel. The researchers conducted a search of the medical literature and identified 32 studies that met criteria for inclusion. These included studies that reported clopidogrel metabolism, platelet reactivity or clinically relevant outcomes (cardiovascular disease [CVD] events and bleeding), and information on CYP2C19 genotype.

The 32 studies included 42,016 patients reporting 3,545 CVD events, 579 stent thromboses, and 1,413 bleeding events. Six studies were randomized trials ("effect-modification" design) and the remaining 26 reported individuals exposed to clopidogrel ("treatment-only" design). In treatment-only analysis, individuals with 1 or more CYP2C19 alleles (an alternative form of a gene) associated with lower enzyme activity had lower levels of active clopidogrel metabolites, less platelet inhibition, lower risk of bleeding, and higher risk of CVD events. However, there was evidence of small-study bias, the authors write. When analyses were restricted to studies with 200 or more events, the point estimate was lessened.

In effect-modification studies, CYP2C19 genotype was not associated with modification of the effect of clopidogrel on CVD end points or bleeding. A limitation included selective outcome reporting.

"Despite associations between CYP2C19 genotype, clopidogrel metabolism, and platelet aggregation, this systematic review and meta-analysis does not demonstrate a clinically important association of genotype with cardiovascular outcomes with the possible exception of stent thrombosis," the researchers write.


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. V. Holmes, P. Perel, T. Shah, A. D. Hingorani, J. P. Casas. CYP2C19 Genotype, Clopidogrel Metabolism, Platelet Function, and Cardiovascular Events: A Systematic Review and Meta-analysis. JAMA: The Journal of the American Medical Association, 2011; 306 (24): 2704 DOI: 10.1001/jama.2011.1880

Cite This Page:

JAMA and Archives Journals. "Analysis does not support genetic test before use of anti-clotting drug." ScienceDaily. ScienceDaily, 27 December 2011. <www.sciencedaily.com/releases/2011/12/111227210716.htm>.
JAMA and Archives Journals. (2011, December 27). Analysis does not support genetic test before use of anti-clotting drug. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2011/12/111227210716.htm
JAMA and Archives Journals. "Analysis does not support genetic test before use of anti-clotting drug." ScienceDaily. www.sciencedaily.com/releases/2011/12/111227210716.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Americans Drink More in the Winter

Americans Drink More in the Winter

Buzz60 (Dec. 22, 2014) The BACtrack breathalyzer app analyzed Americans' blood alcohol content and found out a whole lot of interesting things about their drinking habits. Mara Montalbano (@maramontalbano) has more. Video provided by Buzz60
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins