<unk> , sold under the brand name L-Polamidon among others, is a synthetic opioid analgesic and antitussive which is marketed in Europe and is used for pain management and in opioid maintenance therapy. In addition to being used as a pharmaceutical drug itself,<unk>  is the main therapeutic component of methadone.<unk>  is used for narcotic maintenance in place of, or in some cases alongside as an alternative, to racemic methadone, owing to concern about the cardiotoxic and QT-prolonging action of racemic methadone being exclusively caused by the dextrorotatory enantiomer, dextromethadone.
Levomethadone
Isomethadone
Methadone
Normethadone
Morphine
Buprenorphine
Levacetylmethadol
Dezocine