Clopidogrel Platelet Function Tests
Caveats and Controversies
Clopidogrel is a prodrug that is metabolized to the active metabolite in the liver by 2 oxidation steps mainly using the enzyme produced by the CYP2C19 gene, which is part of the cytochrome P450 system. Several polymorphisms of this gene exist which cause patients to have less function (more common) or more function of their enzyme and hence less or more amount of the active drug present within their bloodstreams. Genetic testing is available to determine which polymorphisms are present in the patient’s genes.
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- 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 (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