isomethadone isomethadone isomethadone (inn, ban; trade nameliden; also known as isoamidone) is a synthetic opioid analgesic and antitussive related to methadone that was used formerly as a pharmaceutical drug but is now no longer marketed. isomethadone was used as both an analgesic and antitussive. it binds to and activates both the μ- and δ-opioid receptors, with the (s)-isomer being the more potent of its two enantiomers. isomethadone is a schedule ii controlled substance in the united states, with an acscn of 9226 and a 2014 aggregate manufacturing quota of 5 g. the salts in use are the hydrobromide (hbr, free base conversion ratio 0.793), hydrochloride (hcl, 0.894), and hcl monohydrate (0.850). isomethadone is also regulated internationally as a schedule i controlled substance under the united nations single convention on narcotic drugs of 1961. isomethadoneclinical dataother nameswin-1783, bw 47-442atc codenonelegal statuslegal status au: s9 (prohibited substance) ca: schedule i de: anlage ii (authorized trade only, not prescriptible) us: schedule ii un: psychotropic schedule i identifiers iupac name (±)-6-(dimethylamino)-5-methyl-4,4-diphenyl-3-hexanone cas number466-40-0 5341-49-1 (hcl)26594-41-2 ((r)-form)561-10-4 ((s)-form)7487-81-2 ((s)-form (hcl))pubchem cid10072chemspider9675unii12l95qd6kvchemical and physical dataformulac21h27nomolar mass309.453 g·mol−13d model (jsmol)interactive image smiles o=c(cc)c(c1=cc=cc=c1)(c(c)cn(c)c)c2=cc=cc=c2 inchi inchi=1s/c21h27no/c1-5-20(23)21(17(2)16-22(3)4,18-12-8-6-9-13-18)19-14-10-7-11-15-19/h6-15,17h,5,16h2,1-4h3key:ifkpljwieqbpgg-uhfffaoysa-n