Title: Butorphanol
CAS Registry Number: 42408-82-2
CAS Name: 17-(Cyclobutylmethyl)morphinan-3,14-diol
Additional Names: (-)-N-cyclobutylmethyl-3,14-dihydroxymorphinan
Manufacturers' Codes: levo-BC-2627
Molecular Formula: C21H29NO2
Molecular Weight: 327.46
Percent Composition: C 77.02%, H 8.93%, N 4.28%, O 9.77%
Literature References: Mixed opioid agonist-antagonist. Prepn: I. Pachter et al., DE 2243961; eidem, US 3819635 (1973, 1974 to Bristol-Myers); I. Monkovic, T. Thomas, US 3775414 (1973 to Bristol-Myers). Total synthesis and pharmacology: I. Monkovic et al., J. Am. Chem. Soc. 95, 7910 (1973); eidem, Can. J. Chem. 53, 3094 (1975). Clinical study: F. Vargas-Arreola et al., Curr. Ther. Res. 22, 186 (1977). Antitussive effect: R. L. Cavanaugh et al., Arch. Int. Pharmacodyn. Ther. 220, 258 (1976). Review: R. C. Heel et al., Drugs 16, 473-505 (1978); F. S. Caruso et al., in Pharmacological and Biochemical Properties of Drug Substances vol. 2, M. E. Goldberg, Ed. (Am. Pharm. Assoc., Washington, DC, 1979) pp 19-57.
Properties: Solid, mp 215-217°. [a]D -70.0° (c = 0.1 in methanol).
Melting point: mp 215-217°
Optical Rotation: [a]D -70.0° (c = 0.1 in methanol)
Derivative Type: Tartrate
CAS Registry Number: 58786-99-5
Trademarks: Stadol (BMS); Torbugesic (Fort Dodge); Torbutrol (BMS)
Molecular Formula: C21H29NO2.C4H6O6
Molecular Weight: 477.55
Percent Composition: C 62.88%, H 7.39%, N 2.93%, O 26.80%
Properties: Solid. mp 217-219°. [a]D22 -64.0° (c = 0.4 in methanol). LD50 in mice, rats (mg/kg): 40-57, 17-20 i.v.; 395-527, 570-756 orally (Heel).
Melting point: mp 217-219°
Optical Rotation: [a]D22 -64.0° (c = 0.4 in methanol)
Toxicity data: LD50 in mice, rats (mg/kg): 40-57, 17-20 i.v.; 395-527, 570-756 orally (Heel)
NOTE: This is a controlled substance: 21 CFR, 1308.14.
Therap-Cat: Analgesic (narcotic).
Therap-Cat-Vet: Analgesic (narcotic); antitussive.
Keywords: Analgesic (Narcotic).
Butoxycaine Butralin Butriptyline Butropium Bromide Butyl Carbitol?

Systematic (IUPAC) name
Clinical data
Trade names Stadol
AHFS/Drugs.com Micromedex Detailed Consumer Information
MedlinePlus a682667
Pregnancy cat. C/D (United States)
Legal status Schedule IV (US)
Routes IV, intranasal
Pharmacokinetic data
Bioavailability Nasal: 60-70%
Metabolism Hepatic hydroxylated & glucuronidated
Half-life 4-7 hours
Excretion Renal, 75%
Biliary, 11-14%
Fecal, 15%
CAS number 42408-82-2 N
ATC code N02AX02 QR05DA90
PubChem CID 5361092
DrugBank DB00611
ChemSpider 16735714 YesY
KEGG D00837 N
Chemical data
Formula C21H29NO2 
Mol. mass 327.473 g/mol
 N (what is this?)  (verify)

Butorphanol (INN) is a morphinan-type synthetic opioid analgesic developed by Bristol-Myers.[1] Brand name Stadol was recently discontinued by the manufacturer. It is now only available in its generic formulations, manufactured by Novex, Mylan, Apotex and Ben Venue Laboratories. Butorphanol is most closely structurally related to levorphanol. Butorphanol is available only as butorphanol tartrate in injectable, tablet, and intranasal spray formulations.