Cytochrome P450 2C19 (encoded by the gene CYP2C19) is a liver enzyme that participates in the activation of the anticoagulant clopidogrel (Plavix) and metabolism of other drugs, such as citalopram. As a result, Clopidrigrel may be less effective in altering platelet activity in those people, who may remain at risk for heart attack, stroke, and cardiovascular death.
Cytochrome P450 2C19 (encoded by the gene CYP2C19) is a liver enzyme that participates in the activation of the anticoagulant clopidogrel (Plavix) and metabolism of other drugs, such as citalopram.
It is estimated that 2% to 14% of the U.S. population are poor metabolizers1.
Poor, and to some extent, intermediate metabolizers may not effectively convert clopidogrel to its active form. As a result, clopidogrel may be less effective in inhibiting platelet activity in those people who may remain at risk for heart attack, stroke, and cardiovascular death.
Ultrarapid CYP2C19 metabolizers may be at risk for bleeding while taking clopidogrel.
Risk for adverse effects from or altered response to other drugs metabolized by CYP2C19, such as citalopram, may be impacted by CYP2C19 genotype.
How to Use This Test:
This test should be ordered when evaluating patients considered for therapies using CYP2C19-metabolized drugs, such as clopidogrel and citalopram, to identify those patients who may be at risk for altered metabolism.
This test can be used to predict anticoagulation response to clopidogrel.
This test can also be used to predict response to and/or risk for adverse events from other drugs metabolized by CYP2C19.
This test is designed to detect a specific set of CYP2C19 variants (*2,*3,*4,*5,*6, *7, *8, *9, *10, and *17).
CYP2C19 variants that produce poor metabolizers are found with frequencies of 2% to 5% in Caucasians, 4% in African Americans, 13% to 23% in Asians, and 38% to 79% in Polynesians and Micronesians.
Based on the individual patient's genotype, dosing adjustment may be required for drugs metabolized via CYP2C19.
Polymerase Chain Reaction (PCR) with Allele-Specific Primer Extension (ASPE)
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Whole Blood EDTA
Day(s) and Time(s) Test Performed:
Monday through Friday; 8 a.m.
1. Pereira N, Stewart AK. Clinical Implementation of Cardiovascular Pharmacogenomics. Mayo Clin Proc. June 2015;90(6):701-704.
Alyssa Frank is a Marketing Segment Manager at Mayo Clinic Laboratories. She leads marketing strategies for product management and specialty testing. Alyssa has worked at Mayo Clinic since 2015.