dextrorphan dextrorphan dextrorphan (dxo) is a psychoactive drug of the morphinan class which acts as an antitussive or cough suppressant and dissociative hallucinogen. it is the dextrorotatory enantiomer of racemorphan; the levorotatory enantiomer is levorphanol. dextrorphan is produced by o-demethylation of dextromethorphan by cyp2d6. dextrorphan is an nmda antagonist and contributes to the psychoactive effects of dextromethorphan. not to be confused with dextromethorphan or dextrallorphan. dextrorphanclinical dataother namesdxo, dextrorphanolatc codenonelegal statuslegal status us: unscheduled identifiers iupac name (+)-17-methyl-9a,13a,14a-morphinan-3-ol cas number125-73-5 ypubchem cid5360697chemspider10489895 nunii04b7qno9wschemblchembl1254766 ncomptox dashboard (epa)dtxsid301014178 echa infocard100.004.323 chemical and physical dataformulac17h23nomolar mass257.377 g·mol−13d model (jsmol)interactive image smiles cn1cc23cccc21cc4c3cc(o)cc4 inchi inchi=1s/c17h23no/c1-18-9-8-17-7-3-2-4-14(17)16(18)10-12-5-6-13(19)11-15(12)17/h5-6,11,14,16,19h,2-4,7-10h2,1h3/t14-,16+,17+/m1/s1 nkey:jaquasynzvunqp-pvavhddusa-n n ny (what is this?) (verify) pharmacology pharmacodynamics dextrorphan siteki (nm)speciesref nmdar(mk-801)486–906rat σ1118–481rat σ211,325–15,582rat mor420>1,000rathuman dor34,700rat kor5,950rat sert401–484rat net≥340rat dat>1,000rat 5-ht1a>1,000rat 5-ht1b/1d54% at 1 μmrat 5-ht2a>1,000rat α1>1,000rat α2>1,000rat β35% at 1 μmrat d2>1,000rat h195% at 1 μmrat machrs100% at 1 μmrat nachrs1,300–29,600(ic50)rat vdscsndndnd values are ki (nm), unless otherwise noted. the smaller the value, the more strongly the drug binds to the site. the pharmacology of dextrorphan is similar to that of dextromethorphan (dxm). however, dextrorphan is much more potent as an nmda receptor antagonist as well much less active as a serotonin reuptake inhibitor, but retains dxm's activity as a norepinephrine reuptake inhibitor. it also has more affinity for the opioid receptors than dextromethorphan, significantly so at high doses. pharmacokinetics dextrorphan has a notably longer elimination half-life than its parent compound, and therefore has a tendency to accumulate in the blood after repeated administration of normally dosed dextromethorphan formulations. it is further converted to 3-hm by cyp3a4 or glucuronidated. society and culture legal status dextrorphan was formerly a schedule i controlled substance in the united states, but was unscheduled on october 1, 1976. research dextrorphan was under development for the treatment of stroke, and reached phase ii clinical trials for this indication, but development was discontinued. environmental presence in 2021, dextrorphan was identified in >75% of sludge samples taken from 12 wastewater treatment plants in california. the same study associated dextrorphan with estrogenic activity by using predictive modelling, before observing it in in vitro.