Category:Drug-metabolizing enzymes

This category collects the wiki's drug-metabolizing-enzyme entity pages: the pharmacogenomics-layer reference pages for the enzymes that metabolize, activate, or inactivate medicines in the human body. Each page follows a common structure (history-first opening, tissue distribution, substrate spectrum with a sortable substrate table, phenotype categories, major variants, inhibitors, inducers, clinical implications, and authoritative external resources) and each is the human-readable companion to the machine-level pk_inhibit_via_<ENZYME> and pk_induce_via_<ENZYME> interaction edges in the wiki's pharmacogenomic interaction layer.

These pages currently live as drafting sandboxes under the Pharmacopedia: project namespace (titled Pharmacogenomics sandbox/Enzyme <NAME>); their permanent home will be the dedicated Enzyme: namespace once it is registered. The closely related transporter, variant, and phenotype pages will live under Transporter:, Variant:, and Phenotype: respectively, and are not collected here.

Cytochrome P450 (CYP) enzymes, the hemoprotein monooxygenases responsible for the majority of phase-I oxidative drug metabolism:

• CYP1A2 (caffeine probe; clozapine, olanzapine, theophylline, tizanidine; the tobacco-smoke induction story)
• CYP2B6 (efavirenz, methadone, bupropion, cyclophosphamide bioactivation)
• CYP2C8 (paclitaxel, repaglinide, the glitazones; the gemfibrozil interaction)
• CYP2C9 (warfarin, phenytoin, NSAIDs, sulfonylureas)
• CYP2C19 (clopidogrel, proton pump inhibitors, several SSRIs, voriconazole)
• CYP2D6 (codeine and tramadol activation, tricyclic antidepressants, many antipsychotics, metoprolol, tamoxifen)
• CYP2E1 (ethanol, acetaminophen bioactivation, the halogenated anesthetics)
• CYP3A4 (the single most clinically consequential drug-metabolizing enzyme; roughly half of all medicines in clinical use)

Phase-II and other non-CYP enzymes:

• UGT1A1 (UDP-glucuronosyltransferase; bilirubin, irinotecan, atazanavir)
• TPMT (thiopurine S-methyltransferase; azathioprine, mercaptopurine, thioguanine)
• NUDT15 (nudix hydrolase; the parallel thiopurine-safety gene with a complementary ancestry distribution to TPMT)

The boundary of this category is "enzyme that metabolizes medicines," not "every gene relevant to pharmacogenomics." Drug transporters (such as SLCO1B1 and ABCB1) move medicines across membranes rather than chemically transforming them, and they are collected separately. The pharmacogenomically important non-enzyme variant loci (such as the HLA-B alleles that govern severe hypersensitivity reactions) are likewise collected separately. Some loci sit at the edge of the boundary: VKORC1, the warfarin target, is a reductase enzyme and may be indexed here when its page is built; G6PD and DPYD are enzymes and belong here when built.