Levorphanol

Levorphanol

Clinical data
Trade names	Levo-dromoran
AHFS/Drugs.com	Monograph
MedlinePlus	a682020
Pregnancy category	US: C (Risk not ruled out)
Dependence liability	High
Routes of administration	oral, intravenous, subcutaneous, intramuscular
ATC code	None
Legal status
Legal status	AU: S8 (Controlled) CA: Schedule I DE: Anlage II (Prohibited) UK: Class A US: Schedule II
Pharmacokinetic data
Bioavailability	70% (oral); 100% (IV)
Protein binding	40%
Metabolism	Hepatic
Biological half-life	11-16 hours
Identifiers
IUPAC name 17-methylmorphinan-3-ol
CAS Number	77-07-6 Y
PubChem (CID)	5359272
IUPHAR/BPS	7595
DrugBank	DB00854 Y
ChemSpider	16736212 Y
UNII	27618J1N2X Y
KEGG	D08123 Y
ChEMBL	CHEMBL592 N
ECHA InfoCard	100.000.912
Chemical and physical data
Formula	C17H23NO
Molar mass	257.371 g/mol
3D model (Jmol)	Interactive image
SMILES CN1CC[C@]23CCCC[C@H]2[C@H]1CC4=C3C=C(O)C=C4
InChI InChI=1S/C17H23NO/c1-18-9-8-17-7-3-2-4-14(17)16(18)10-12-5-6-13(19)11-15(12)17/h5-6,11,14,16,19H,2-4,7-10H2,1H3/t14-,16+,17+/m0/s1 Y Key:JAQUASYNZVUNQP-USXIJHARSA-N Y
NY (what is this?)

Levorphanol /lɛvaʊrfɑːnɒl/ (brand name Levo-Dromoran) is an opioid medication used to treat moderate to severe pain. Chemically, it is (−)-3-hydroxy-N-methyl-morphinan. It is the levorotatory stereoisomer of racemorphan, first described in Germany in 1948 as an orally-active morphine-like analgesic. It has been in clinical use in the U.S. since 1953.

Levorphanol acts predominantly as an agonist of the μ-opioid receptor, but is also an agonist of the δ-opioid, κ-opioid, and nociceptin receptors, as well as an NMDA receptor antagonist and a serotonin-norepinephrine reuptake inhibitor. Levorphanol, similarly to certain other opioids, also acts as a glycine receptor antagonist and GABA receptor antagonist at very high concentrations. Levorphanol is 6-8 times as potent as morphine at the mu-opioid receptor.

Relative to morphine, levorphanol lacks complete cross-tolerance and possesses greater intrinsic activity at the MOR. 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. Levorphanol's exceptionally high analgesic efficacy in the treatment of neuropathy is also conferred by its action on serotonin and norepinephrine transporters, similar to the opioids tramadol and tapentadol, and mutually complements the analgesic effect of its NMDA antagonization.