Drug Metabolism · Pharmacology

Which Phase I enzyme is responsible for the metabolism of roughly 25% of all clinical drugs and exhibits significant genetic polymorphism (e.g., poor vs. ultra-rapid metabolizers)?

  1. CYP2D6
  2. CYP3A4
  3. CYP2C19
  4. CYP1A2
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Correct answer: CYP2D6

CYP2D6 is highly polymorphic, affecting the metabolism of antidepressants, antipsychotics, and opioids like Codeine. Depending on a patient's genetic makeup, they may experience either toxicity or a complete lack of therapeutic response.

Difficulty: Medium Question 8 of 20

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