norhydrocodone norhydrocodone norhydrocodone is the major metabolite of the opioid analgesic hydrocodone. it is formed from hydrocodone in the liver via n-demethylation predominantly by cyp3a4. unlike hydromorphone, a minor metabolite of hydrocodone, norhydrocodone is described as inactive. however, norhydrocodone is actually an agonist of the μ-opioid receptor with similar potency to hydrocodone, but has been found to produce only minimal analgesia when administered peripherally to animals. this is likely due to poor blood-brain-barrier and thus central nervous system penetration. norhydrocodoneclinical dataother names(5α)-3-methoxy-4,5-epoxymorphinan-6-oneidentifiers iupac name (4r,4ar,7ar,12bs)-9-methoxy-2,3,4,4a,5,6,7a,13-octahydro-1h-4,12-methanobenzofuroisoquinoline-7-one cas number5083-62-5pubchem cid13001738chemspider32698944unii18nb5f1jt4comptox dashboard (epa)dtxsid70198862 chemical and physical dataformulac17h19no3molar mass285.343 g·mol−13d model (jsmol)interactive image smiles coc1=c2c3=c(c453(ccn4)(o2)c(=o)cc5)c=c1 inchi inchi=1s/c17h19no3/c1-20-13-5-2-9-8-11-10-3-4-12(19)16-17(10,6-7-18-11)14(9)15(13)21-16/h2,5,10-11,16,18h,3-4,6-8h2,1h3/t10-,11+,16-,17-/m0/s1key:jgoruxkmrlijsv-ynhqpcigsa-n