Table 1. CYP2C19 Genotype Results, Antiplatelet Therapy Recommendations, and Physician Response for N=6 Patients.
| CYP2C19 Genotype | CYP2C19 Phenotypea | Number (%) Patients | Antiplatelet Therapy Recommendation | Physician Response |
|---|---|---|---|---|
| *1/*1 | Normal metabolizer (fully functional enzyme activity) | 3 (50%) | Clopidogrel 75mg daily | Approved (100%) |
| *1/*2 | Intermediate metabolizer (decreased enzyme activity) | 1 (17%) | Ticagrelor 90 mg twice daily | Approved (100%) |
| *1/*17 | Rapid metabolizer (increased enzyme activity compared to normal metabolizers) | 1 (17%) | Clopidogrel 75mg daily | Approved (100%) |
| *2/*17b | Intermediate metabolizer (decreased enzyme activity) | 1 (17%) | Clopidogrel 75mg daily | Approved (100%) |
a
CYP2C19 phenotypes are based on consensus terms outlined in reference 4.
b
Although the current 2013 Clinical Pharmacogenetics Implementation Consortium (CPIC) recommends using an alternative to clopidogrel for CYP2C19*2/*17 (outlined in reference 28), the 2011 CPIC guidelines available at the time the study was conducted did not discuss the CYP2C19*2/*17 genotype nor did the guidelines provide recommendations to utilize alternative therapy. Therefore, the clinical pharmacist recommended clopidogrel for this patient.