Clinical data
Routes of
ATC code
  • none
  • 17-Cyclopropylmethyl-6,7-dehydro-4,5-epoxy -3,14-dihydroxy-6,7,2',3'-indolomorphinan
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass414.505 g·mol−1
3D model (JSmol)
  • Oc4c3O[C@H]7c2c(c1ccccc1[nH]2)C[C@@]6(O)[C@H]5N(CC[C@@]67c3c(cc4)C5)CC8CC8
  • InChI=1S/C26H26N2O3/c29-19-8-7-15-11-20-26(30)12-17-16-3-1-2-4-18(16)27-22(17)24-25(26,21(15)23(19)31-24)9-10-28(20)13-14-5-6-14/h1-4,7-8,14,20,24,27,29-30H,5-6,9-13H2/t20-,24+,25+,26-/m1/s1 checkY

Naltrindole is a highly potent, highly selective delta opioid receptor antagonist used in biomedical research. In May 2012 a paper was published in Nature with the structure of naltrindole in complex with the mouse δ-opioid G-protein coupled receptor, solved by X-ray crystallography.[1]

Drug design

Since peptide compounds are unable to cross the blood–brain barrier, researchers developed naltrindole to be a non-peptide antagonist analog of the delta-preferring endogenous opiate enkephalin. Enkephalin contains an aromatic phenyl group on its Phe4 residue, which was hypothesized to be the "address" sequence responsible for the opiate's delta opioid receptor affinity.[2] Thus, attachment of a phenyl-containing indole molecule to the C-ring of naltrexone's morphinan base successfully produced a drug with the high receptor affinity of naltrexone, but which binds almost exclusively to the delta opioid receptor.[3]


  1. ^ Granier S, Manglik A, Kruse AC, Kobilka TS, Thian FS, Weis WI, Kobilka BK (May 2012). "Structure of the δ-opioid receptor bound to naltrindole". Nature. 485 (7398): 400–4. Bibcode:2012Natur.485..400G. doi:10.1038/nature11111. PMC 3523198. PMID 22596164.
  2. ^ Lipkowski AW, Tam SW, Portoghese PS (July 1986). "Peptides as receptor selectivity modulators of opiate pharmacophores". Journal of Medicinal Chemistry. 29 (7): 1222–5. doi:10.1021/jm00157a018. PMID 2879914.
  3. ^ Portoghese PS, Sultana M, Takemori AE (January 1988). "Naltrindole, a highly selective and potent non-peptide delta opioid receptor antagonist". European Journal of Pharmacology. 146 (1): 185–6. doi:10.1016/0014-2999(88)90502-X. PMID 2832195.