Clopidogrel Platelet Function Tests
Caveats and Controversies
Why Do Genetic Testing?

December 2011
Patients with two loss of function alleles are at risk of experiencing thrombosis while taking clopidogrel. Increasing the dose for these patients may not be adequate and they may require a change of medication. The number of poor metabolizers is approximately 4% of European Americans and African Americans and is somewhat higher in Asian Americans. People from Polynesia or Micronesia have a much higher likelihood of being poor metabolizers.
Why Do Genetic Testing? |
Jump to section:
- Introduction
- Learning Objectives
- Platelet Function Tests for the Detection of Clopidogrel Resistance1
- Platelet Function Tests for the Detection of Clopidogrel Resistance
- Caveat: There Is No Perfect Platelet Function Test...
- Problems With Testing For Clopidogrel
- How We Choose a Testing Method
- Methodology Table
- Platelet Function Testing Available at Mayo Clinic Florida
- Light Transmission Platelet Aggregometry Studies (LTA)
- Platelet Aggregation (Cont'd)
- Normal Patient
- Accumetrics VerifyNow Test
- VerifyNow P2Y12 Test
- P2Y12 Test Interferences
- P2Y12 Antagonists2
- Can These Platelet Function Tests Be Used for Ticagrelor (Brilinta/Brilique)?
- PFA-100
- PFA–100 (Cont'd)
- INNOVANCE PFA P2Y
- TEG — Platelet Mapping
- Results of VerifyNow Testing
- 2009–2011 Clopidogrel Response at 30%
- Genetic Testing: Clopidogrel Metabolism
- Clopidogrel Metabolism
- Number of Gene Polymorphisms
- Clopidogrel Metabolism and Genetic Polymorphisms
- Why Do Genetic Testing?
- Clopidogrel Genetics (Cont'd)
- Caveats — Other Reasons for Poor Response to Clopidogrel
- CYP2C19 Polymorphism May Require Another Factor
- Controversy for Clopidogrel
- Warning: Diminished Effectiveness In Poor Metabolizers
- What Does Warning Mean For Clinicians With Patients On Clopidogrel?
- FDA Answer
- More Questions
- Summary
- References
- Questions?
- Disclosure


