Clinical data
ATC code
  • none
  • 2-(1-Benzofuran-4-yl)-N-methyl-N-[(5R,7S,8S)-7-pyrrolidin-1-yl-1-oxaspiro[4.5]decan-8-yl]acetamide
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass396.531 g·mol−1
3D model (JSmol)
  • O=C(Cc1cccc2occc12)N(C)C1CCC2(CCCO2)CC1N1CCCC1
  • InChI=1S/C24H32N2O3/c1-25(23(27)16-18-6-4-7-22-19(18)9-15-28-22)20-8-11-24(10-5-14-29-24)17-21(20)26-12-2-3-13-26/h4,6-7,9,15,20-21H,2-3,5,8,10-14,16-17H2,1H3/t20-,21-,24-/m0/s1 checkY

Enadoline is a drug which acts as a highly selective κ-opioid agonist.

In human studies, it produced visual distortions and feelings of dissociation, reminiscent of the effects of salvinorin A.[1]

It was studied as a potential analgesic, but abandoned because of the dose-limiting effects of dysphoria, which could be expected from a κ-opioid agonist. There was mention of its potential in treating comatose head injury or stroke victims, where that type of side effect would be immaterial.[2]


When enadoline was first reported in 1990, it was "the most potent κ-selective analgesic ever reported ... 25 times more potent than morphine and 17 times more potent than U-62066".[3]


  1. ^ Walsh SL, Strain EC, Abreu ME, Bigelow GE (2001). "Enadoline, a selective kappa opioid agonist: comparison with butorphanol and hydromorphone in humans". Psychopharmacology. 157 (2): 151–62. doi:10.1007/s002130100788. PMID 11594439. S2CID 10507758.
  2. ^ Barber A, Gottschlich R (1997). "Novel developments with selective, non-peptidic kappa-opioid receptor agonists". Expert Opin Investig Drugs. 6 (10): 1351–68. doi:10.1517/13543784.6.10.1351. PMID 15989506.
  3. ^ Halfpenny, Paul R.; Horwell, David C.; Hughes, John; Hunter, John C.; Rees, David C. (1990). "Highly selective .kappa.-opioid analgesics. 3. Synthesis and structure-activity relationships of novel N-[2-(1-pyrrolidinyl)-4- or -5-substituted cyclohexyl]arylacetamide derivatives". Journal of Medicinal Chemistry. 33 (1): 286–91. doi:10.1021/jm00163a047. PMID 2153208.