A patient undergoes coronary stenting and is started on clopidogrel. Genetic testing reveals he is a CYP2C19 poor metabolizer. What is the primary clinical consequence of this polymorphism?
- A Increased risk of bleeding
- B Accelerated clearance of the active metabolite
- C Therapeutic failure and stent thrombosis ✓
- D Enhanced conversion of clopidogrel to its toxic metabolite
Correct answer: C. Therapeutic failure and stent thrombosis
Explanation
Clopidogrel is a prodrug requiring CYP2B19 for conversion to its active metabolite. Poor metabolizers have reduced active metabolite formation, leading to therapeutic failure and increased risk of stent thrombosis. Bleeding is a risk in ultra-rapid metabolizers, not poor metabolizers.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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