CYP2C19
Cytochrome P450 2C19
What it does
Metabolizes clopidogrel, proton pump inhibitors, several SSRIs, and voriconazole. Variants determine whether drugs are activated or cleared at expected rates.
Why this matters for Black patients
Patients with African ancestry carry CYP2C19*2 and *3 (loss-of-function) alleles at substantially higher rates. For clopidogrel, this means the drug fails to activate and patients remain at high cardiovascular risk.
Common variants
| Variant | Phenotype | African | European |
|---|---|---|---|
| *17 | Rapid metabolizer (gain of function) | 0.180 | 0.210 |
| *2 | Poor metabolizer (loss of function) | 0.150 | 0.130 |
| *3 | Poor metabolizer (loss of function) | 0.010 | 0.001 |
Note: This page is reference information, not medical advice. Pharmacogenomic differences are about ancestry, not race; race is an imperfect proxy. Discuss any medication changes with your prescriber.