Pharmacogenomic topic · dashboard states: NM · PM · IM · UM
PGx describes inherited differences in drug handling. AUC measures total exposure, not benefit or toxicity by itself. Ask whether the pathway clears a drug or activates it: slower clearance can raise exposure; slower activation can reduce benefit. Lower inactive-metabolite exposure does not imply lost efficacy.
Dashboard vocabulary: NM = Normal metabolizer; PM = Poor metabolizer; IM = Intermediate metabolizer; UM = Ultrarapid metabolizer. RM = Rapid metabolizer appears only under CYP2C19; EXP = Expresser appears only under CYP3A5. These interface labels do not establish clinical phenotypes for every gene. Prescribing uses the laboratory report, current guidance and monitoring.
Test at a glance
Clears some medicines and activates others.
Clinical role
Codeine forms morphine; tramadol forms active O-desmethyltramadol. PMs may get inadequate analgesia; UMs risk excess activation and toxicity. CPIC recommends avoiding both drugs in both groups.
Practical pearls
Reduced activity can instead raise exposure to drugs cleared by CYP2D6.
Strong inhibitors can make a genetically normal metabolizer function like a PM: phenoconversion.
Safety / monitoring
Check pain relief, sedation, breathing and interactions. Opioid age restrictions still apply.
Self-check
Why may codeine fail in a PM? Too little morphine is formed.
Is faster metabolism always safer? No. Rapid activation can cause serious toxicity.