Systematic (IUPAC) name
Clinical data
Trade names Levo-dromoran
  • US: C (Risk not ruled out)
Legal status
Routes of
oral, intravenous, subcutaneous, intramuscular
Pharmacokinetic data
Bioavailability 70% (oral); 100% (IV)
Protein binding 40%
Metabolism Hepatic
Biological half-life 11-16 hours
CAS Registry Number  Y
ATC code None
PubChem CID:
DrugBank  Y
ChemSpider  Y
Chemical data
Formula C17H23NO
Molecular mass 257.371 g/mol

Levorphanol (Levo-Dromoran) is an opioid medication used to treat moderate to severe pain. Chemically it is (−)-3-hydroxy-N-methyl-morphinan.[1] It is the levorotatory stereoisomer of the synthetic morphinan (Dromoran) and a pure opioid agonist, first described in Germany in 1948 as an orally active morphine-like analgesic.[2] It has been in clinical use in the U.S. since the 1950s.[1] Levorphanol has opioid, NMDA antagonist and monoamine reuptake inhibitor activity; it binds strongly to the mu opioid receptor and less strongly to the kappa and delta opioid receptors but lacks complete cross-tolerance with morphine.[1] It possesses greater intrinsic activity at the MOR than morphine.[1] The duration of action is generally long compared to other comparable analgesics and varies from 4 hours to as much as 15 hours. For this reason levorphanol is useful in palliation of chronic pain and similar conditions. Levorphanol has an oral to parenteral effectiveness ratio of 2:1, one of the most favourable of the strong narcotics. Its NMDA actions, similar to those of the phenylheptylamine open-chain narcotics such as methadone or the phenylpiperidine ketobemidone, make levorphanol useful for types of pain that other analgesics may not be as effective against, such as neuropathic pain.[3]

Levorphanol is listed under the Single Convention On Narcotic Drugs 1961 and is regulated like morphine in most countries. In the United States it is a Schedule II Narcotic controlled substance with a DEA ACSCN of 9220 and 2013 annual aggregate manufacturing quota of 4.5 kilos. The salts in use are the tartrate (free base conversion ratio 0.58) and hydrobromide (0.76) [4]


By the resolution of the racemate (i.e. racemorphan):[5]

See also


  1. ^ a b c d Davis, MP; Glare, PA; Hardy, J (2009) [2005]. Opioids in Cancer Pain (2nd ed.). Oxford, UK: Oxford University Press.  
  2. ^ DE 1014545 
  3. ^ Prommer, E (2007). "Levorphanol: the forgotten opioid.". Supportive Care in Cancer 15 (3): 259–264.  
  4. ^ http://www.deadiversion.usdoj.gov/quotas/conv_factor/index.html
  5. ^ Schnider, O.; Gr�Ssner, A. (1951). "Oxy-morphinane. (3. Mitteilung). Optisch aktive 3-Oxy-morphinane". Helvetica Chimica Acta 34 (7): 2211.