metheptazine metheptazine metheptazine is an opioid analgesic from the phenazepane family. it was developed by american home products in the 1950s. metheptazineclinical dataother namesmetheptazineatc codenoneidentifiers iupac name methyl 1,2-dimethyl-4-phenylazepane-4-carboxylate cas number469-78-3 ypubchem cid3047717chemspider2310051 yunii93x4r66p5achemblchembl2104520 nchemical and physical dataformulac16h23no2molar mass261.365 g·mol−13d model (jsmol)interactive image smiles o=c(oc)c2(c1ccccc1)cc(n(c)ccc2)c inchi inchi=1s/c16h23no2/c1-13-12-16(15(18)19-3,10-7-11-17(13)2)14-8-5-4-6-9-14/h4-6,8-9,13h,7,10-12h2,1-3h3 ykey:raafyfkwmrwoit-uhfffaoysa-n y ny (what is this?) (verify) metheptazine produces similar effects to other opioids, including analgesia, sedation, dizziness and nausea. metheptazine is not listed as a controlled substance under the controlled substances act 1970 in the united states. the canadian controlled drugs and substances act specifically excludes the phenazepine opioids from control.