Levomethorphan

---

title: "Levomethorphan" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["delta-opioid-receptor-agonists", "enantiopure-drugs", "gaba-receptor-antagonists", "glycine-receptor-antagonists", "hallucinogenic-kappa-opioid-receptor-agonists", "nmda-receptor-antagonists", "morphinans", "mu-opioid-receptor-agonists", "nociceptin-receptor-agonists", "phenol-ethers", "prodrugs", "semisynthetic-opioids", "serotonin–norepinephrine-reuptake-inhibitors"] description: "Opioid analgesic" topic_path: "general/delta-opioid-receptor-agonists" source: "https://en.wikipedia.org/wiki/Levomethorphan" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Opioid analgesic ::

| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 462091038 | IUPAC_name = (1R,9R,10R)-4-methoxy-17-methyl-17-azatetracyclo[7.5.3.01,10.02,7]heptadeca-2(7),3,5-triene | image = Levomethorphan.svg | image_class = skin-invert-image | image2 = Levometorfan.png | image_class2 = bg-transparent

| tradename = | MedlinePlus = | pregnancy_AU = | pregnancy_US = | legal_AU = S9 | legal_BR = A1 | legal_BR_comment = | legal_CA = Schedule I | legal_US = Schedule II | dependency_liability = High | addiction_liability = High | legal_UK = Class A | legal_DE = Anlage I

| elimination_half-life = 3-6 hours

| CAS_number_Ref = | CAS_number = 125-70-2 | ATC_prefix = None | PubChem = 5362449 | DrugBank_Ref = | DrugBank = | ChemSpiderID_Ref = | ChemSpiderID = 4642423 | UNII_Ref = | UNII = 7ZZ22K9QE6 | ChEBI_Ref = | ChEBI = 146176 | ChEMBL_Ref = | ChEMBL = 1908323 | KEGG_Ref = | KEGG = D12696

| C = 18 | H = 25 | N = 1 | O = 1 | smiles = COc1ccc2C[C@@H]3[C@@H]4CCCC[C@]4(CCN3C)c2c1 | StdInChI_Ref = | StdInChI = 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+/m0/s1 | StdInChIKey_Ref = | StdInChIKey = MKXZASYAUGDDCJ-CGTJXYLNSA-N

Levomethorphan (LVM) (INN, BAN) is an opioid analgesic of the morphinan family that has never been marketed. It is the L-stereoisomer of racemethorphan (methorphan). The effects of the two isomers of racemethorphan are quite different, with dextromethorphan (DXM) being an antitussive at low doses and a hallucinogen at much higher doses. Levomethorphan is about five times stronger than morphine.

Levomethorphan is a prodrug to levorphanol, analogously to DXM acting as a prodrug to dextrorphan or codeine behaving as a prodrug to morphine. As such, levomethorphan has similar effects to levorphanol but is less potent as it must be demethylated to the active form by liver enzymes before being able to produce its effects. As a prodrug of levorphanol, levomethorphan functions as a potent agonist of all three of the opioid receptors, μ, κ (κ1 and κ3 but notably not κ2), and δ, as an NMDA receptor antagonist, and as a serotonin-norepinephrine reuptake inhibitor. Via activation of the κ-opioid receptor, levomethorphan can produce dysphoria and psychotomimetic effects such as dissociation and hallucinations.

Levomethorphan 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 9210 and a 2014 annual aggregate manufacturing quota of 195 grams, up from 6 grams the year before. The salts in use are the tartrate (free base conversion ratio 0.644) and hydrobromide (0.958). At the current time, no levomethorphan pharmaceuticals are marketed in the United States.

References

References

1. Anvisa. (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial". [[Diário Oficial da União]].
2. (14 November 2014). "The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies". Springe.
3. (31 January 2005). "Organic Chemistry". Cengage Learning.
4. (1996). "Handbook of Analytical Therapeutic Drug Monitoring and Toxicology". CRC Press.
5. (January 2016). "Levorphanol use: past, present and future". Postgraduate Medicine.
6. (12 October 2009). "Cancer Pain: Assessment and Management". Cambridge University Press.
7. "Conversion Factors for Controlled Substances". U.S. Department of Justice, Drug Enforcement Administration (DEA).

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::