Systematic (IUPAC) name
(5R,6R,7R,9R,13S,14R)-7-[(R)-2-Hydroxypentan-2-yl] -6-methoxy-17-methyl-4,5-epoxy-6,14-ethanomorphinan-3-ol
Clinical data
Legal status
CAS number  YesY
ATC code None
ChemSpider  YesY
Chemical data
Formula C25H35NO4 
Mol. mass 413.5497 g/mol

Dihydroetorphine was developed by K. W. Bentley at McFarlan-Smith in the 1960s[1] and is a potent opioid analgesic,[2] which is used mainly in China. It is a derivative of the more well-known opioid etorphine, which is used as a very potent veterinary painkiller and anesthetic medication, primarily for the sedation of large animals such as elephants, giraffes and rhinos.

Dihydroetorphine is a semi-synthetic opioid, used mainly as a strong painkiller for humans.[3] It is several thousand times stronger than morphine (between 1000x and 12000x more potent depending what method is used for comparison),[1] although it is poorly absorbed when taken orally. Sublingual forms of dihydroetorphine are used in China at doses ranging from 20 to 40µg repeated every 3-4 hours, and are reported to cause strong analgesia and relatively mild side effects compared to other opioids, although all the usual opioid side effects such as dizziness, sedation, nausea, constipation, and respiratory depression can occur. Transdermal patches of dihydroetorphine have also been developed.[4]

Dihydroetorphine is considered to be somewhat less addictive than many other opioids, and is also sometimes used in China as a substitute maintenance drug for opioid addicts,[5] in a similar way to how the related drug buprenorphine is used in western nations.[6][7]


  1. ^ a b Bentley, K. W.; Hardy, D. G. (1967). "Novel analgesics and molecular rearrangements in the morphine-thebaine group. 3. Alcohols of the 6,14-endo-ethenotetrahydrooripavine series and derived analogs of N-allylnormorphine and -norcodeine". Journal of the American Chemical Society 89 (13): 3281–3292.  
  2. ^ Martin, T. J.; Hairston, C. T.; Lutz, P. O.; Harris, L. S.; Porreca, F. (1998). "Anti-allodynic actions of intravenous opioids in the nerve injured rat: Potential utility of heroin and dihydroetorphine against neuropathic pain". European Journal of Pharmacology 357 (1): 25–32.  
  3. ^ Lewis, J. W.; Husbands, S. M. (2004). "The orvinols and related opioids--high affinity ligands with diverse efficacy profiles". Current Pharmaceutical Design 10 (7): 717–732.  
  4. ^ Ohmori, S.; Morimoto, Y. (2002). "Dihydroetorphine: a potent analgesic: pharmacology, toxicology, pharmacokinetics, and clinical effects". CNS Drug Reviews 8 (4): 391–404.  
  5. ^ Bo-Yi, Q. (1996). "Advances in dihydroetorphine: From analgesia to detoxification". Drug Development Research 39 (2): 131–134.  
  6. ^ Gerak, L. R.; Gauthier, C. R.; France, C. R. (2003). "Discriminative stimulus and antinociceptive effects of dihydroetorphine in rhesus monkeys". Psychopharmacology 166 (4): 351–359.  
  7. ^ Husbands, S. M.; Lewis, J. W. (2003). "Opioid ligands having delayed long-term antagonist activity: potential pharmacotherapies for opioid abuse". Mini Reviews in Medicinal Chemistry 3 (2): 137–144.  
  • "List of drugs in Schedule II of the Controlled Substances Act". DEA.