{{Short description|Chemical compound}} {{Drugbox | verifiedrevid = 437136317 | IUPAC_name = (5α)-4,5-Epoxy-3,14-dihydroxy-17-(2-methoxyethyl)morphinan-6-one | image = Semorphone.svg | image_class = skin-invert-image | width = 200
<!--Clinical data--> | tradename = | pregnancy_AU = <!-- A / B1 / B2 / B3 / C / D / X --> | pregnancy_US = <!-- A / B / C / D / X --> | pregnancy_category = | legal_AU = <!-- Unscheduled / S2 / S3 / S4 / S5 / S6 / S7 / S8 / S9 --> | legal_CA = <!-- / Schedule I, II, III, IV, V, VI, VII, VIII --> | legal_UK = <!-- GSL / P / POM / CD / Class A, B, C --> | legal_US = <!-- Schedule I ? --> | legal_status = | routes_of_administration =
<!--Pharmacokinetic data--> | bioavailability = | protein_bound = | metabolism = | elimination_half-life = | excretion =
<!--Identifiers--> | CAS_number = 88939-40-6 | ATC_prefix = none | ATC_suffix = | PubChem = 5491906 | DrugBank_Ref = {{drugbankcite|correct|drugbank}} | DrugBank = | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 4590760 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 2HD55617I2
<!--Chemical data--> | C=19 | H=23 | N=1 | O=5 | smiles = O=C4[C@@H]5Oc1c2c(ccc1O)C[C@H]3N(CC[C@]25[C@@]3(O)CC4)CCOC | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C19H23NO5/c1-24-9-8-20-7-6-18-15-11-2-3-12(21)16(15)25-17(18)13(22)4-5-19(18,23)14(20)10-11/h2-3,14,17,21,23H,4-10H2,1H3/t14-,17+,18+,19-/m1/s1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = PBGIBLLOMGURPS-GRGSLBFTSA-N | synonyms = }}
'''Semorphone''' ('''Mr 2264''') is an opiate analogue that is an ''N''-substituted derivative of oxymorphone.
Semorphone is a partial agonist at μ-opioid receptors. It is around twice the potency of morphine, but with a ceiling effect on both analgesia and respiratory depression<ref>{{cite journal | vauthors = Behne M, Bremerich D, Heinrich J, Schumacher H, Scherer M | s2cid = 33001046 | title = Respiratory effects and tolerability of Mr 2264 Cl. A new opiate partial agonist in comparison with morphine and placebo | journal = European Journal of Clinical Pharmacology | volume = 46 | issue = 4 | pages = 301–4 | year = 1994 | pmid = 7957512 | doi = 10.1007/BF00194395 }}</ref> which means that these effects stop becoming any stronger after a certain maximum dose.
It is not currently used in medicine, and is not a controlled drug, although it might be considered to be a controlled substance analogue of oxymorphone on the grounds of its related chemical structure in some jurisdictions such as the United States, Canada, Australia and New Zealand.
== References == {{Reflist}}
{{Opioidergics}}
Category:4,5-Epoxymorphinans Category:Opioids Category:Hydroxyarenes Category:Tertiary alcohols Category:Cyclic ketones Category:Ethers Category:Mu-opioid receptor agonists
{{analgesic-stub}}