Adverse drug reactions represent a leading cause of preventable hospitalizations. Clinical pharmacogenomics utilizes high-throughput genotyping to tailor drug selection and dosage based on an individual's unique enzymatic clearance profile.
Key Cytochrome P450 Enzymes and Metabolic Phenotypes
Patients are categorized across standard metabolic phenotypes based on gene duplication or loss-of-function alleles:
- CYP2D6: Metabolizes over 25% of clinical medications (antidepressants, beta-blockers, antiarrhythmics, codeine). Poor metabolizers face drug accumulation; ultra-rapid metabolizers risk rapid prodrug intoxication.
- CYP2C19: Governs clopidogrel (Plavix) activation and proton pump inhibitor metabolism.
- VKORC1 & CYP2C9: Guide precise therapeutic dosing algorithms for narrow therapeutic index anticoagulants like warfarin.