Levallorphan

Levallorphan

Clinical data
AHFS/Drugs.com	International Drug Names
Routes of administration	Oral
ATC code	none
Legal status
Legal status	℞ (Prescription only)
Identifiers
IUPAC name (−)-17-allylmorphinan-3-ol
CAS Number	152-02-3 Y
PubChem (CID)	5359371
IUPHAR/BPS	7209
DrugBank	DB00504 N
ChemSpider	4514267 Y
UNII	353613BU4U Y
ChEMBL	CHEMBL1254682 N
ECHA InfoCard	100.005.273
Chemical and physical data
Formula	C19H25NO
Molar mass	283.4079 g/mol
3D model (Jmol)	Interactive image
SMILES Oc1ccc3c(c1)[C@@]24[C@H]([C@H](N(CC2)C\C=C)C3)CCCC4
InChI InChI=1S/C19H25NO/c1-2-10-20-11-9-19-8-4-3-5-16(19)18(20)12-14-6-7-15(21)13-17(14)19/h2,6-7,13,16,18,21H,1,3-5,8-12H2/t16-,18-,19-/m0/s1 Y Key:OZYUPQUCAUTOBP-WDSOQIARSA-N Y
NY (what is this?)

Levallorphan (INN, BAN) (brand names Lorfan, Naloxifan, Naloxiphan), also known as levallorphan tartate (USAN), is an opioid modulator of the morphinan family used as an opioid analgesic and opioid antagonist/antidote. It acts as an antagonist of the μ-opioid receptor (MOR) and as an agonist of the κ-opioid receptor (KOR), and as a result, blocks the effects of stronger agents with greater intrinsic activity such as morphine whilst simultaneously producing analgesia.

Levallorphan was formerly widely used in general anesthesia, mainly to reverse the respiratory depression produced by opioid analgesics and barbiturates used for induction of surgical anaesthesia whilst maintaining a degree of analgesia (via KOR agonism). It is now less commonly employed for this purpose as the newer drug naloxone tends to be used instead. Levallorphan was also used in combination with opioid analgesics to reduce their side effects, mainly in obstetrics, and a very small dose of levallorphan used alongside a full agonist of the MOR can produce greater analgesia than when the latter is used by itself. The combination of levallorphan with pethidine (meperidine) was indeed used so frequently, a standardized formulation was made available, known as Pethilorfan.