Plavix May Be Less Effective for People of East Asian Descent: Here’s Why

According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death in the U.S. as of 2019. Two of the most serious complications of heart disease are strokes and acute coronary syndrome (ACS) — the technical term for when you have a heart attack or unstable chest pain. It’s estimated that every 40 seconds, someone has either a heart attack or a stroke.

Once you have one of these heart-related incidents, it’s likely you will be instructed to take multiple medications to prevent them from happening again. Among your prescriptions may be a medication called clopidogrel (Plavix). While experts recommended it as a first choice, research has found that it may be less effective in people of East Asian descent, putting them at a higher risk for these serious medical emergencies.

Here, we’ll cover the details of why Plavix may be less effective in some populations, how to know if you’re affected by this warning, and what alternatives are available.

What is Plavix?

Plavix is an antiplatelet medication. It helps prevent platelets (a type of blood cell) from sticking together and forming clots that can cause heart attacks and strokes. To work properly, your body uses a special enzyme, or protein, called CYP2C19 to digest the medication. Whether or not you can use this enzyme is determined by your genes.

How is Plavix used?

Plavix is an oral tablet that you take by mouth once a day. It is typically taken along with aspirin after you’ve had a stroke, heart attack, or another type of ACS. Depending on your personal health risks, you may be on Plavix for several months or long term. Because Plavix works to prevent blood clots, more bleeding and bruising than usual are possible side effects.

What warning has the FDA issued about Plavix?

In March 2010, the FDA issued a warning stating that some people cannot digest Plavix because their bodies cannot use the CYP2C19 enzyme required. This means that when they take the medication, it doesn’t work. In the medical community, this enzyme problem is known as “poor drug metabolism” and, if this happens to you with Plavix, you are at a higher risk for heart attacks and strokes.

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Who is affected by the FDA warning about Plavix?

As mentioned earlier, your ability to use the enzyme is determined by your genes. While this genetic problem can affect anyone of any race or ethnicity, those who are of East Asian descent are more likely to be affected. Specifically, research has shown that the CYP2C19 gene issue is present in about 2% of white, 4% of Black, and 14% of Chinese people.

Why are people of East Asian descent less likely to have the gene that helps metabolize Plavix?

Currently, experts don’t know why this genetic difference exists. It is possible to have metabolism problems with multiple enzymes, and they all seem to be passed down from generation to generation. The study of how genes change medication effectiveness — called pharmacogenomics — is still a relatively new area of medicine. Hopefully, as this field advances, we can better understand why certain people are predisposed to inherited issues like this.

How do I know if I can’t metabolize Plavix?

If you are concerned that you could have problems metabolizing Plavix, speak with your provider. Together, you can discuss if it would be more cost-effective to test you for the CYP2C19 gene or switch you to an alternative antiplatelet medication. But, it’s a good idea to have this conversation when your provider first wants to prescribe Plavix so you can start with the most effective medication.

Is genetic testing available to find out if I can’t metabolize Plavix?

Yes. With a simple blood test, you can find out if you have the CYP2C19 gene. Much like other blood tests, you would go to a laboratory where a phlebotomist would draw blood from your veins into a small tube and send it off to be evaluated. These tests usually cost between $300 and $400 without insurance and take about a week to process.

What are the risks of taking Plavix if I can’t metabolize it?

Because people without the CYP2C19 gene cannot properly digest Plavix, the medication will not work if you have this genetic issue. Taking it in that case has the same risks as not taking it at all — a higher risk of having a stroke or heart attack. So, it’s very important to discuss your options and whether you should be tested with your provider.

What are the alternatives to Plavix?

There are two current alternatives available if you can’t metabolize Plavix. Brilinta (ticagrelor) can be used for both heart attack and stroke prevention. Prasugrel (Effient) can be used to prevent a heart attack but must be avoided if you’ve had a stroke in the past. Neither of these medications uses the CYP2C19 enzyme to work in the body.

It’s important to know that these alternatives do have a higher risk of causing serious bleeding as a side effect. They may also be more expensive than Plavix. But they will be effective and help prevent future heart attacks or strokes. And that’s key when you don’t have the CYP2C19 gene.

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Written by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

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