Plavix® is prescribed for any of the following reasons:
•	To prevent strokes and heart attacks in people at increased risk due to: ° hardening of the arteries (also called atherosclerosis) ° narrowing of the arteries outside the heart such as arteries in the pelvis and legs (also called peripheral artery disease) ° sudden, reduced blood flow to the heart (also called acute coronary syndrome) ° a recent heart attack or stroke.
•	To reduce the risk of blood clots in people who: ° are having a coronary artery stent placed ° have an artificial heart valve ° have mitral valve disease (a condition that affects the control of blood flow between the top and bottom chambers of the left side of the heart).

Plavix® is the 3rd most commonly prescribed brand name drug, with over 25 million prescriptions written in the year 2009.1

Plavix® is a brand name for the drug clopidogrel bisulfate. Other brand names of this drug include: Clopilet® and Ceruven®

For CYP2C19 and many other genes involved in drug response, there are multiple genetic variants that impact the way the body responds to a drug.

Your response to clopidogrel is determined by your specific combination of genetic variants, not simply by the number of variants that you have. Each combination of genetic variants in or near a gene is called a “haplotype”. There can be many different combinations of variants for each gene. To distinguish one combination of variants from another, scientists sometimes use a numbering system. For example: one combination of variants within the CYP2C19 gene may be called “star 2”, written as *2, while another combination is *1.

Since we have two copies of each gene, one from our mother and one from our father, each person will have a combination of variants (called a haplotype) from each parent. When genetic testing is performed the results are noted as two numbers (one representing each combination of variants in that gene), separated by a slash. For example, someone who inherited the combination of variants from their mother known as *2 and the combination known as *3 from their father would be a *2/*3 for the gene tested. Some people have combinations of variants that are rare and have not been studied or named. Sometimes, the genetic test that is performed cannot determine a person’s result with certainty.

Different combinations of variants in the CYP2C19 gene can be used to predict how a person will respond to a particular drug, like clopidogrel. A person’s predicted response, called a “metabolizer type” is based on the two CYP2C19 haplotypes they inherited from their parents.

CYP2C19 metabolizer status categories and predicted response to clopidogrel:

Reduced CYP2C19 activity	Poor Metabolizer  Not likely to receive full benefit of clopidogrel. Increased risk for heart attack and stroke.
	Intermediate Metabolizer May not receive full benefit of clopidogrel.  Possible increased risk for heart attack and stroke.
Typical CYP2C19 activity	Extensive Metabolizer Expected to benefit from standard clopidogrel dose.
Increased CYP2C19 activity	Ultra-Rapid Metabolizer Expected to process medication more quickly. Possible increased benefit. Possible increased risk for bleeding.
Uncertain CYP2C19 activity	Metabolizer Status Uncertain Not enough data to determine clopidogrel response.

In some cases the expected response to clopidgrel is not known and cannot be predicted. In some cases the expected genetic testing provides enough information to determine the general response category (e.g. reduced activity) but the specific metabolizer type cannot be predicted.

The frequency of each metabolizer group can be different in each racial or ethnic group. Your personal CPMC results will show how common each metabolizer group is in your racial or ethnic group. You can view this information in your personal report by clicking on the ABOUT tab and then the HOW COMMON tab. Information is not available for all racial or ethnic groups. If data is not available for your race or ethnicity your report will include information for the Caucasian population.

Example:

Some drugs (both prescription and over the counter) may decrease the effect of clopidogrel or increase the risk for side effects. Talk to your health care provider if you are taking clopidogrel in addition to any of the following drugs:
•	Nonsteroidal anti-inflammatory drugs (NSAIDS). These drugs, commonly prescribed for analgesic (pain reducing), antipyretic (fever-reducing), and anti-inflammatory effects can cause gastrointestinal bleeding when taken with clopidogrel. Common types of NSAIDS include: aspirin, ibuprofen (Motrin, Advil), and naproxen (Alleve).
•	Proton Pump Inhibitors (PPIs). Commonly used to treat heartburn, peptic ulcers and other gastrointestinal conditions, PPIs can reduce the effect of clopidogrel, making it less effective at preventing blood clots. Examples of PPIs include: Prilosec, Zegerid, and Prevacid.
•	Warfarin. When taken in combination with clopidogrel, warfarin (Coumadin) has been shown to increase the risk for bleeding.
For a list of medications that interact with clopidogrel, click here. It is important that you talk to your healthcare providers about all of the medications (both over-the-counter and prescription) as well as supplements that you are taking, as they may interact with clopidogrel. Do NOT make any changes to ANY medications without talking to your healthcare providers.

There are no known food interactions with clopidogrel.

As you can see from the sample results table below, each variant tested is listed by its “rs number”, the number used by scientists to name genetic variants. In the next column of the table you will find your results. Because we have two copies of every gene, one from mom and one from dad, everyone tested will have two results, represented by letters (example: CT) for each variant tested. In the last column, we display the reference value. The reference value shows the result for someone who is expected to have a normal or ‘typical’ response to clopidogrel. Since it is your personal combination of variants that is important in interpreting your results, you will be provided with the common name for your combination of results. For example, in the sample table below, the combination of variants in the CYP2C19 gene are also referred to as CYP2C19*1/*17. People who have a CYP2C19*1/*17 result are ultra-rapid metabolizers. For more information on ultra rapid metabolizers and other CYPC2C19 metabolizer types see “The Impact of CYP2C19 Gene Variants on Clopidogrel Response” (above). SAMPLE REPORT: In addition to the RESULT tab which will show your personal result for each variant tested, you will be provided with an interpretation (found on the INTERPRETATION tab). The interpretation will give you information about how your personal result will impact how your body metabolizes clopidogrel. In some cases this information will not be known. SAMPLE REPORT:

It is important to note that CPMC testing alone cannot fully predict your response to Plavix® or any other drug. Other factors like body weight, other health conditions, and other medications may also influence the way a person will respond to Plavix® and other drugs. It is possible that you may have other genetic variants that occur in the CYP2C19 gene that are not tested by the CPMC. Also, it is possible that you may have variants in other genes that influence your response to Plavix®.