Systematic (IUPAC) name
Clinical data
Legal status
CAS number
5341-49-1 (HCl)
26594-41-2 ((R)-form)
561-10-4 ((S)-form)
7484-81-2 ((S)-form (HCl))
ATC code None
Synonyms WIN-1783, BW 47-442
Chemical data
Formula C21H27NO 
Mol. mass 309.445 g/mol

Isomethadone (INN, BAN; Liden), 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.[1][2][3][4] It binds to and activates both the μ- and δ-opioid receptors, with the (S)-isomer being the more potent of its two enantiomers.[5] Isomethadone is a Schedule II controlled substance in the United States, and is also regulated internationally as a Schedule I controlled substance under the United Nations Single Convention on Narcotic Drugs of 1961.[6]

See also


  1. ^ F.. Macdonald (1997). Dictionary of Pharmacological Agents. CRC Press. p. 1169.  
  2. ^ Dr. Ian Morton; Ian K. M. Morton; Judith M. Hall; Dr. Judith Hall (1999). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer. p. 157.  
  3. ^ KEATS AS, BEECHER HK (June 1952). "Analgesic potency and side action liability in man of heptazone, WIN 1161-2, 6-methyl dihydromorphine, Metopon, levo-isomethadone and pentobarbital sodium, as a further effort to refine methods of evaluation of analgesic drugs". The Journal of Pharmacology and Experimental Therapeutics 105 (2): 109–29.  
  4. ^ WINTER CA, FLATAKER L (November 1952). "Antitussive action of d-isomethadone and d-methadone in dogs". Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.) 81 (2): 463–5.  
  5. ^ Portoghese PS, Poupaert JH, Larson DL, et al. (June 1982). "Synthesis, X-ray crystallographic determination, and opioid activity of erythro-5-methylmethadone enantiomers. Evidence which suggests that mu and delta opioid receptors possess different stereochemical requirements". Journal of Medicinal Chemistry 25 (6): 684–8.  
  6. ^ Thomas Nordegren (1 March 2002). The A-Z Encyclopedia of Alcohol and Drug Abuse. Universal-Publishers. p. 366.