Dextromethorphan

Dextromethorphan

Clinical data
Trade names	Robitussin, Delsym, DM, DexAlone, Duract
AHFS/Drugs.com	Monograph
MedlinePlus	a682492
Pregnancy category	AU: A US: C (Risk not ruled out)
Dependence liability	Low
Routes of administration	Oral
ATC code	R05DA09 (WHO)
Legal status
Legal status	AU: S2 (Pharmacy only) CA: OTC UK: Pharmacy medicines US: OTC
Pharmacokinetic data
Bioavailability	11%
Metabolism	Hepatic (liver) enzymes: major CYP2D6, minor CYP3A4, and minor CYP3A5
Biological half-life	2-4 hours (extensive metabolisers); 24 hours (poor metabolisers)
Excretion	Renal
Identifiers
IUPAC name (4bS,8aR,9S)-3-Methoxy-11-methyl-6,7,8,8a,9,10-hexahydro-5H-9,4b-(epiminoethano)phenanthrene
CAS Number	125-71-3 Y
PubChem (CID)	15978238
IUPHAR/BPS	6953
DrugBank	DB00514 Y
ChemSpider	13109865 Y
UNII	7355X3ROTS Y
KEGG	D03742 Y
ChEBI	CHEBI:4470 N
ChEMBL	CHEMBL52440 Y
ECHA InfoCard	100.004.321
Chemical and physical data
Formula	C18H25NO
Molar mass	271.40 g/mol
3D model (Jmol)	Interactive image
Melting point	111 °C (232 °F)
SMILES CN1CC[C@@]23CCCC[C@@H]2[C@@H]1Cc4c3cc(cc4)OC
InChI InChI=1S/C18H25NO/c1-19-10-9-18-8-4-3-5-15(18)17(19)11-13-6-7-14(20-2)12-16(13)18/h6-7,12,15,17H,3-5,8-11H2,1-2H3/t15-,17+,18+/m1/s1 Y Key:MKXZASYAUGDDCJ-NJAFHUGGSA-N Y
NY (what is this?)

Dextromethorphan (DXM or DM) is a drug of the morphinan class with sedative, dissociative, and stimulant properties (at higher doses). It is a cough suppressant in many over-the-counter cold and cough medicines including generic labels and store brands, Benylin DM, Mucinex DM, Camydex-20 tablets, Robitussin, NyQuil, Dimetapp, Vicks, Coricidin, Delsym, TheraFlu, Cheracol D, and others. Dextromethorphan has also found numerous other uses in medicine, ranging from pain relief (as either the primary analgesic, or an opioid potentiator) over psychological applications to the treatment of addiction. It is sold in syrup, tablet, spray, and lozenge forms. In its pure form, dextromethorphan occurs as a white powder.

DXM is also used recreationally. When exceeding label-specified maximum dosages, dextromethorphan acts as a dissociative anesthetic. Its mechanism of action is via multiple effects, including actions as a nonselective serotonin reuptake inhibitor and a sigma-1 receptor agonist. DXM and its major metabolite, dextrorphan, also act as an NMDA receptor antagonist at high doses, which produces effects similar to, yet distinct from, the dissociative states created by other dissociative anesthetics such as ketamine and phencyclidine. Further, the metabolite 3-methoxymorphinan of dextrorphan (thus a second-level metabolite of DXM) produces local anesthetic effects in rats with potency above dextrorphan, but below that of DXM.