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Levallorphan Stats & Data

Opioid

PubChem CID 5359371

NPS DataHub

MW283.41

FormulaC19H25NO

CAS152-02-3

IUPAC(−)-17-allylmorphinan-3-ol

SMILESC=CCN1CCC23CCCCC3C1Cc1ccc(O)cc12

InChIKeyOZYUPQUCAUTOBP-QXAKKESOSA-N

Chemical Class Morphinan

Pharmacology

DrugBank

Half-life 1 hour State Solid Absorption Rapidly absorbed. Metabolism Hepatic.

Description

An opioid antagonist with properties similar to those of naloxone; in addition it also possesses some agonist properties. It should be used cautiously; levallorphan reverses severe opioid-induced respiratory depression but may exacerbate respiratory depression such as that induced by alcohol or other non-opioid central depressants. (From Martindale, The Extra Pharmacopoeia, 30th ed, p683)

Mechanism of Action

Levallorphan antagonizes opioid effects by competing for the same receptor sites. It binds to the opioid mu receptor and the nicotinic acetylcholine receptor alpha2/alpha3.

Pharmacodynamics

Levallorphan, an opioid antagonist similar to naloxone, is used to treat drug overdoses. Levallorphan differs from naloxone in that it also possesses some agonist properties. It is an analogue of levelorphanol that counteracts the actions of narcotic analgesics such as morphine. It is used especially in the treatment of respiratory depression due to narcotic overdoses. Levallorphan prevents or reverses the effects of opioids including respiratory depression, sedation and hypotension. Also, it can reverse the psychotomimetic and dysphoric effects of agonist-antagonists such as pentazocine.

Indication

For the complete or partial reversal of narcotic depression, including respiratory depression, induced by opioids.

Measured Affinities

Guide to PHARMACOLOGY

Measured binding and functional data for levallorphan, curated by the IUPHAR/BPS Guide to PHARMACOLOGY. Each row cites the paper it came from. Lower concentrations mean tighter binding — a value in the sub-nanomolar range indicates a very potent interaction.

Target	Action	Measure	Value	Concentration	Species	Source
μ receptor OPRM1	Antagonist	pKi	—	—	Human	PMID 21621410

Reading this. pKi, pEC50 and pIC50 are negative log molar values, so a higher number means a tighter interaction; the concentration column converts them for you. Values from non-human species are laboratory measurements and do not translate directly to human effect. Receptor affinity is not a dose — it describes what a molecule binds, not how much of it is safe to take.

Receptor data from the IUPHAR/BPS Guide to PHARMACOLOGY (v2026.2), licensed CC BY-SA 4.0. Matched to this substance by InChIKey.

Toxicity

DrugBank

Toxicity (DrugBank)

Oral, rat LD₅₀: 109±4 mg/kg

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