CYP2C19 Genotyping & Pharmacogenetic Testing

CYP2c19 is part of a family of genes that create important enzymes that metabolize medications. CYP2C19 influences drug interaction of about 5-10% of the prescription medications currently being used. There is a lot genetic variation for CYP2C19 that affects how the enzyme is produced and how it behaves. This has a great impact on how patients metabolize their medications. Depending on a patient’s ethnic background the genetic variations of they CYP2C19 gene can be very different.

  • Only 3% to 6% of individuals of European or African decent are considered poor metabolizers in regards to this enzyme.
  •  13% to 23% of individuals with Asian ethnic origins have genetic variations that would make them poor metabolizers.
  • However, an estimated 38-79% of individuals with Polynesian heritage are poor metabolizers. Which is why, PGx testing is recommended highly for this group.

Medications Affected By CYP2C19 Genetic Variations

Plavix, also known by its pharmaceutical name clopidogrel, is affected by the CYP2C19 enzyme. If a patient has a genetic variation that would affect how they metabolize Plavix, they are likely to have issues with the medication. As a blood thinner, this can cause serious problems. Some studies find that individuals with genetic variations experience either side effects or medicine inefficacy when taking Plavix. However, like many of the cytochrome P-450 enzymes, there are other factors that also affect the production and behavior of CYP2C19.

Other Factors To Consider When Ordering PGx Testing

The FDA has required Plavix to display pharmcogenetic data on its label since 2010. This is because multiple studies have drawn similar conclusions between medicine inefficacy and genetic variations. That being said, there are other factors that can cause variations in how an individual produces enzymes. One of the most important factors is tobacco use. Patients who are actively smoking tobacco products might alter how their body produces CYP2C19 enzymes. Additionally patients who quit smoking can also see a change in their production of enzymes. For this reason, patients with a history of tobacco use are stronger candidates for PGx testing, as they are more likely to metabolize medications at different rates than an average patient.

Pharmacogenetic Testing for Plavix

If you want to order pharmacogenetic testing for your patient on Plavix, please contact the TruGenX team. We test up to 22 different genes for variations that affect prescription medication metabolization. For patients currently taking Plavix or simply interested in learning more about drug interactions with personal genetics please visit our guide on PGx testing. Patients should ask their physician about the benefits of PGx testing and how it can improve their treatment.