PH10.7 | PH10.7 | Pharmacogenomics and Pharmacoeconomics in Drug Choice — SDL Guide — Summary & Reflection

KEY TAKEAWAYS

Pharmacogenomics explains inter-individual variation in drug response through genetic polymorphisms in CYP450 enzymes (CYP2D6, CYP2C19, CYP2C9), drug-metabolising enzymes (TPMT), drug targets, and immune-response genes (HLA alleles). Clinically actionable tests include G6PD screening before primaquine, TPMT testing before azathioprine, and HLA-B*5701 screening before abacavir. CYP2D6 ultrarapid metaboliser status is a clinical concern with codeine; CYP2C19 poor metaboliser status affects clopidogrel antiplatelet response. Pharmacoeconomic analysis compares drug options by cost and outcome: cost-minimisation (equivalent outcomes), cost-effectiveness (natural units), cost-utility (QALYs), and cost-benefit (monetary). The practical skill is finding and comparing drug prices using Jan Aushadhi and NPPA resources — generic NLEM drugs reduce patient out-of-pocket costs dramatically for chronic conditions. Both frameworks should be integrated: pharmacogenomics changes the drug choice when there is a known safety/efficacy risk; pharmacoeconomics selects the most cost-effective option among equivalents.

REFLECT

Consider a patient in your current clinical placement who is on long-term medication for a chronic condition. Do you know whether they are paying out-of-pocket? What is the monthly cost of their regimen? Is there a Jan Aushadhi outlet near their home? Could any of their medications be replaced by an NLEM generic without compromising clinical outcomes? Now consider: if pharmacogenomic testing were universally available at zero cost in your hospital, which test would you most want to run on which patients? What patient harm would that prevent? What does the gap between that ideal and current practice tell you about healthcare system priorities?