Nalodeine

Nalodeine
Clinical data
Other names	N-Allylnorcodeine
Identifiers
	IUPAC name (4R,4aR,7S,7aR,12bS)-9-methoxy-3-prop-2-enyl-2,4,4a,7,7a,13-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinoline-7-ol;
CAS Number	56195-50-7 ;
PubChem CID	5486632;
ChemSpider	4588998;
UNII	YD9M6BEL6S;
CompTox Dashboard (EPA)	DTXSID80971582 ;
Chemical and physical data
Formula	C20H23NO3
Molar mass	325.408 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES COC1=C2C3=C(CC4C5C3(CCN4CC=C)C(O2)C(C=C5)O)C=C1;
	InChI InChI=1S/C20H23NO3/c1-3-9-21-10-8-20-13-5-6-15(22)19(20)24-18-16(23-2)7-4-12(17(18)20)11-14(13)21/h3-7,13-15,19,22H,1,8-11H2,2H3/t13-,14+,15-,19-,20-/m0/s1; Key:XAOWELGMJQTJQR-WYIOCLOVSA-N;

Nalodeine, also known more commonly as N-allylnorcodeine, is an opioid antagonist (specifically, an antagonist of the μ-opioid receptor) that was never marketed but is notable as the first opioid antagonist to be discovered.^[1]^[2] It was first reported in 1915 and was found to block the effects of morphine in animals.^[3]^[2] This was followed by the clinical introduction of nalorphine (N-allylnormorphine) in 1954, naloxone (N-allyloxymorphone) in 1960, and naltrexone (N-methylcyclopropyloxymorphone) in 1963.^[2] Nalmefene (6-desoxy-6-methylene-naltrexone), another structurally related opioid antagonist derivative, was also subsequently introduced, in 1996.^[4] In animals, nalodeine both reverses morphine- and heroin-induced respiratory depression and acts as a respiratory stimulant in its own right (i.e., when given alone).^[5] Similarly to nalorphine, nalodeine has also been found to act as an agonist of the κ-opioid receptor.^[6]