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Identification
NameButorphanol
Accession NumberDB00611  (APRD00835)
TypeSmall Molecule
GroupsApproved, Illicit, Vet Approved
DescriptionA synthetic morphinan analgesic with narcotic antagonist action. It is used in the management of severe pain. [PubChem]
Structure
Thumb
Synonyms
(-)-17-(Cyclobutylmethyl)morphinan-3,14-diol
(-)-Butorphanol
(-)-N-Cyclobutylmethyl-3,14-dihydroxymorphinan
Butorfanol
Butorphanol
Butorphanolum
External Identifiers
  • BC-2627
  • levo-BC 2627
Approved Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Butorphanol Nasal SpraySolution10 mgNasalAa Pharma Inc2000-08-01Not applicableCanada
PMS-butorphanolSpray10 mgNasalPharmascience Inc2002-06-07Not applicableCanada
Stadol NS - 10mg/ml Aem-liqAerosol, metered; Liquid10 mgNasalBristol Myers Squibb Canada1994-12-312004-08-04Canada
Approved Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Butorphanol TartrateInjection, solution2 mg/mLIntramuscular; IntravenousWest Ward Pharmaceuticals Corp2009-05-01Not applicableUs
Butorphanol TartrateInjection, solution2 mg/mLIntramuscular; IntravenousGeneral Injectables & Vaccines, Inc2013-08-14Not applicableUs
Butorphanol TartrateSolution10 mg/mLNasalApotex Corp.2002-12-04Not applicableUs
Butorphanol TartrateInjection, solution1 mg/mLIntramuscular; IntravenousHospira, Inc.1997-01-23Not applicableUs
Butorphanol TartrateSpray, metered10 mg/mLNasalA S Medication Solutions Llc2002-03-12Not applicableUs
Butorphanol TartrateSpray, metered10 mg/mLNasalWest Ward Pharmaceuticals Corp.2002-03-12Not applicableUs
Butorphanol TartrateInjection, solution2 mg/mLIntramuscular; IntravenousHospira, Inc.1997-01-23Not applicableUs
Butorphanol TartrateInjection2 mg/mLIntramuscular; IntravenousCardinal Health1998-10-15Not applicableUs
Butorphanol TartrateInjection, solution1 mg/mLIntramuscular; IntravenousWest Ward Pharmaceuticals Corp2009-05-01Not applicableUs
Butorphanol TartrateSpray10 mg/mLNasalMylan Pharmaceuticals Inc.2011-01-21Not applicableUs
Butorphanol TartrateInjection1 mg/mLIntramuscular; IntravenousCardinal Health1998-10-15Not applicableUs
Approved Over the Counter ProductsNot Available
Unapproved/Other Products Not Available
International Brands
NameCompany
ButaroLotus Pharmaceuticals
ButrumAristo
StadolBristol-Myers Squibb
Stadol NSCephalon
Brand mixturesNot Available
Salts
Name/CASStructureProperties
Butorphanol Tartrate
58786-99-5
Thumb
  • InChI Key: GMTYREVWZXJPLF-AFHUBHILSA-N
  • Monoisotopic Mass: 477.236267101
  • Average Mass: 477.5473
DBSALT000276
Categories
UNIIQV897JC36D
CAS number42408-82-2
WeightAverage: 327.4605
Monoisotopic: 327.219829177
Chemical FormulaC21H29NO2
InChI KeyIFKLAQQSCNILHL-QHAWAJNXSA-N
InChI
InChI=1S/C21H29NO2/c23-17-7-6-16-12-19-21(24)9-2-1-8-20(21,18(16)13-17)10-11-22(19)14-15-4-3-5-15/h6-7,13,15,19,23-24H,1-5,8-12,14H2/t19-,20+,21-/m1/s1
IUPAC Name
(1S,9R,10S)-17-(cyclobutylmethyl)-17-azatetracyclo[7.5.3.0¹,¹⁰.0²,⁷]heptadeca-2(7),3,5-triene-4,10-diol
SMILES
[H][C@@]12CC3=C(C=C(O)C=C3)[C@]3(CCCC[C@@]13O)CCN2CC1CCC1
Pharmacology
IndicationFor the relief of moderate to severe pain.
Structured Indications
PharmacodynamicsButorphanol is a synthetic opioid agonist-antagonist analgesic with a pharmacological and therapeutic profile that has been well established since its launch as a parenteral formulation in 1978. The introduction of a transnasal formulation of butorphanol represents a new and noninvasive presentation of an analgesic for moderate to severe pain. This route of administration bypasses the gastrointestinal tract, and this is an advantage for a drug such as butorphanol that undergoes significant first-pass metabolism after oral administration. The onset of action and systemic bioavailability of butorphanol following transnasal delivery are similar to those after parenteral administration. Butorphanol blocks pain impulses at specific sites in the brain and spinal cord.
Mechanism of actionThe exact mechanism of action is unknown, but is believed to interact with an opiate receptor site in the CNS (probably in or associated with the limbic system). The opiate antagonistic effect may result from competitive inhibition at the opiate receptor, but may also be a result of other mechanisms. Butorphanol is a mixed agonist-antagonist that exerts antagonistic or partially antagonistic effects at mu opiate receptor sites, but is thought to exert its agonistic effects principally at the kappa and sigma opiate receptors.
TargetKindPharmacological actionActionsOrganismUniProt ID
Kappa-type opioid receptorProteinyes
agonist
HumanP41145 details
Delta-type opioid receptorProteinyes
agonist
HumanP41143 details
Mu-type opioid receptorProteinyes
partial antagonist
HumanP35372 details
Related Articles
AbsorptionRapidly absorbed after intramuscular injection and peak plasma levels are reached in 20-40 minutes. The absolute bioavailability is 60-70% and is unchanged in patients with allergic rhinitis. In patients using a nasal vasoconstrictor (oxymetazoline) the fraction of the dose absorbed was unchanged, but the rate of absorption was slowed. Oral bioavailability is only 5-17% because of extensive first-pass metabolism.
Volume of distribution
  • 305 to 901 L
Protein bindingSerum protein binding is approximately 80%.
Metabolism

Extensively metabolized in the liver. The pharmacological activity of butorphanol metabolites has not been studied in humans; in animal studies, butorphanol metabolites have demonstrated some analgesic activity.

Route of eliminationButorphanol is extensively metabolized in the liver. Elimination occurs by urine and fecal excretion.
Half lifeThe elimination half-life of butorphanol is about 18 hours. In renally impaired patients with creatinine clearances <30 mL/min the elimination half-life is approximately doubled. After intravenous administration to patients with hepatic impairment, the elimination half-life of butorphanol was approximately tripled.
Clearance
  • 99 +/- 23 L/h [Young with IV 2 mg]
  • 82 +/- 21 [Eldery with IV 2 mg]
ToxicityThe clinical manifestations of butorphanol overdose are those of opioid drugs in general. The most serious symptoms are hypoventilation, cardiovascular insufficiency, coma, and death.
Affected organisms
  • Humans and other mammals
PathwaysNot Available
SNP Mediated EffectsNot Available
SNP Mediated Adverse Drug ReactionsNot Available
Interactions
Drug Interactions
DrugInteractionDrug group
1,1,1,2 TetrafluoroethaneThe risk or severity of adverse effects can be increased when Butorphanol is combined with 1,1,1,2 Tetrafluoroethane.Investigational
2,5-Dimethoxy-4-ethylamphetamine2,5-Dimethoxy-4-ethylamphetamine may increase the analgesic activities of Butorphanol.Experimental, Illicit
3,4-Methylenedioxyamphetamine3,4-Methylenedioxyamphetamine may increase the analgesic activities of Butorphanol.Experimental, Illicit
3,4-Methylenedioxymethamphetamine3,4-Methylenedioxymethamphetamine may increase the analgesic activities of Butorphanol.Experimental, Illicit
4-Bromo-2,5-dimethoxyamphetamine4-Bromo-2,5-dimethoxyamphetamine may increase the analgesic activities of Butorphanol.Experimental, Illicit
7-NitroindazoleThe risk or severity of adverse effects can be increased when Butorphanol is combined with 7-Nitroindazole.Experimental
AcepromazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Acepromazine.Approved, Vet Approved
AceprometazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Aceprometazine.Approved
AcetazolamideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Acetazolamide.Approved, Vet Approved
AclidiniumThe risk or severity of adverse effects can be increased when Aclidinium is combined with Butorphanol.Approved
adipiplonThe risk or severity of adverse effects can be increased when Butorphanol is combined with adipiplon.Investigational
AgomelatineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Agomelatine.Approved, Investigational
AlfaxaloneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Alfaxalone.Vet Approved
AlfentanilButorphanol may decrease the analgesic activities of Alfentanil.Approved, Illicit
AlimemazineAlimemazine may increase the hypotensive activities of Butorphanol.Approved, Vet Approved
AlphacetylmethadolButorphanol may decrease the analgesic activities of Alphacetylmethadol.Experimental, Illicit
AlprazolamThe risk or severity of adverse effects can be increased when Alprazolam is combined with Butorphanol.Approved, Illicit, Investigational
AlvimopanThe risk or severity of adverse effects can be increased when Butorphanol is combined with Alvimopan.Approved
AmilorideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Amiloride.Approved
AmisulprideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Amisulpride.Approved, Investigational
AmitriptylineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Amitriptyline.Approved
Ammonium chlorideAmmonium chloride may increase the excretion rate of Butorphanol which could result in a lower serum level and potentially a reduction in efficacy.Approved, Vet Approved
AmobarbitalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Amobarbital.Approved, Illicit
AmoxapineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Amoxapine.Approved
AmperozideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Amperozide.Experimental
AmphetamineAmphetamine may increase the analgesic activities of Butorphanol.Approved, Illicit
Anisotropine MethylbromideThe risk or severity of adverse effects can be increased when Anisotropine Methylbromide is combined with Butorphanol.Approved
AripiprazoleThe risk or severity of adverse effects can be increased when Butorphanol is combined with Aripiprazole.Approved, Investigational
ArticaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Articaine.Approved
AsenapineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Asenapine.Approved
Atracurium besylateThe risk or severity of adverse effects can be increased when Atracurium besylate is combined with Butorphanol.Approved
AtropineThe risk or severity of adverse effects can be increased when Atropine is combined with Butorphanol.Approved, Vet Approved
AzaperoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Azaperone.Vet Approved
AzelastineButorphanol may increase the central nervous system depressant (CNS depressant) activities of Azelastine.Approved
AzelastineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Azelastine.Approved
AzosemideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Azosemide.Investigational
BaclofenThe risk or severity of adverse effects can be increased when Butorphanol is combined with Baclofen.Approved
BarbitalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Barbital.Illicit
BenactyzineThe risk or severity of adverse effects can be increased when Benactyzine is combined with Butorphanol.Withdrawn
BendroflumethiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Bendroflumethiazide.Approved
BenperidolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Benperidol.Investigational
BenzatropineThe risk or severity of adverse effects can be increased when Benzatropine is combined with Butorphanol.Approved
BenzocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Benzocaine.Approved
BenzphetamineBenzphetamine may increase the analgesic activities of Butorphanol.Approved, Illicit
Benzyl alcoholThe risk or severity of adverse effects can be increased when Butorphanol is combined with Benzyl alcohol.Approved
BezitramideButorphanol may decrease the analgesic activities of Bezitramide.Experimental, Illicit, Withdrawn
BiperidenThe risk or severity of adverse effects can be increased when Biperiden is combined with Butorphanol.Approved
BL-1020BL-1020 may increase the hypotensive activities of Butorphanol.Investigational
BrexpiprazoleThe risk or severity of adverse effects can be increased when Butorphanol is combined with Brexpiprazole.Approved
BrimonidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Brimonidine.Approved
BrimonidineBrimonidine may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved
BromazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Bromazepam.Approved, Illicit
BrompheniramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Brompheniramine.Approved
BrotizolamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Brotizolam.Approved, Withdrawn
BumetanideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Bumetanide.Approved
BupivacaineThe risk or severity of adverse effects can be increased when Bupivacaine is combined with Butorphanol.Approved, Investigational
BuprenorphineButorphanol may increase the central nervous system depressant (CNS depressant) activities of Buprenorphine.Approved, Illicit, Investigational, Vet Approved
BuspironeThe risk or severity of adverse effects can be increased when Buspirone is combined with Butorphanol.Approved, Investigational
ButabarbitalThe risk or severity of adverse effects can be increased when Butabarbital is combined with Butorphanol.Approved, Illicit
ButacaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Butacaine.Vet Approved
ButalbitalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Butalbital.Approved, Illicit
ButambenThe risk or severity of adverse effects can be increased when Butorphanol is combined with Butamben.Approved
ButethalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Butethal.Approved, Illicit
Canrenoic acidThe risk or severity of adverse effects can be increased when Butorphanol is combined with Canrenoic acid.Approved, Withdrawn
CanrenoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Canrenone.Investigational
CarbamazepineThe risk or severity of adverse effects can be increased when Carbamazepine is combined with Butorphanol.Approved, Investigational
CarbinoxamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Carbinoxamine.Approved
CarfentanilButorphanol may decrease the analgesic activities of Carfentanil.Illicit, Vet Approved
CarisoprodolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Carisoprodol.Approved
CetirizineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cetirizine.Approved
Chloral hydrateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chloral hydrate.Approved, Illicit, Vet Approved
ChlordiazepoxideThe risk or severity of adverse effects can be increased when Chlordiazepoxide is combined with Butorphanol.Approved, Illicit
ChlormezanoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chlormezanone.Approved, Withdrawn
ChloroprocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chloroprocaine.Approved
ChlorothiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chlorothiazide.Approved, Vet Approved
ChlorphenamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chlorphenamine.Approved
ChlorphenoxamineThe risk or severity of adverse effects can be increased when Chlorphenoxamine is combined with Butorphanol.Withdrawn
ChlorphentermineChlorphentermine may increase the analgesic activities of Butorphanol.Illicit, Withdrawn
ChlorpromazineThe risk or severity of adverse effects can be increased when Chlorpromazine is combined with Butorphanol.Approved, Vet Approved
ChlorprothixeneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chlorprothixene.Approved, Withdrawn
ChlorthalidoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chlorthalidone.Approved
ChlorzoxazoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Chlorzoxazone.Approved
CicletanineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cicletanine.Investigational
CinchocaineThe risk or severity of adverse effects can be increased when Cinchocaine is combined with Butorphanol.Approved, Vet Approved
CitalopramButorphanol may increase the serotonergic activities of Citalopram.Approved
ClemastineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clemastine.Approved
ClidiniumThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clidinium.Approved
ClobazamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clobazam.Approved, Illicit
clomethiazoleThe risk or severity of adverse effects can be increased when Butorphanol is combined with clomethiazole.Investigational
ClomipramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clomipramine.Approved, Vet Approved
ClonazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clonazepam.Approved, Illicit
ClonidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clonidine.Approved
ClorazepateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Clorazepate.Approved, Illicit
ClozapineThe risk or severity of adverse effects can be increased when Clozapine is combined with Butorphanol.Approved
CocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cocaine.Approved, Illicit
CodeineButorphanol may decrease the analgesic activities of Codeine.Approved, Illicit
ConivaptanThe risk or severity of adverse effects can be increased when Butorphanol is combined with Conivaptan.Approved, Investigational
CyclizineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cyclizine.Approved
CyclobenzaprineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cyclobenzaprine.Approved
CyclopentolateThe risk or severity of adverse effects can be increased when Cyclopentolate is combined with Butorphanol.Approved
CyclothiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cyclothiazide.Approved
CyproheptadineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Cyproheptadine.Approved
DantroleneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Dantrolene.Approved
DapiprazoleThe risk or severity of adverse effects can be increased when Dapiprazole is combined with Butorphanol.Approved
DapoxetineButorphanol may increase the serotonergic activities of Dapoxetine.Investigational
DarifenacinThe risk or severity of adverse effects can be increased when Darifenacin is combined with Butorphanol.Approved, Investigational
deramciclaneThe risk or severity of adverse effects can be increased when Butorphanol is combined with deramciclane.Investigational
DesfluraneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Desflurane.Approved
DesipramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Desipramine.Approved
DesloratadineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Desloratadine.Approved, Investigational
DesmopressinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Desmopressin.Approved
DesvenlafaxineButorphanol may increase the serotonergic activities of Desvenlafaxine.Approved
DetomidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Detomidine.Vet Approved
DexbrompheniramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Dexbrompheniramine.Approved
DexetimideThe risk or severity of adverse effects can be increased when Dexetimide is combined with Butorphanol.Withdrawn
DexmedetomidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Dexmedetomidine.Approved, Vet Approved
DextroamphetamineDextroamphetamine may increase the analgesic activities of Butorphanol.Approved, Illicit
DextromoramideButorphanol may decrease the analgesic activities of Dextromoramide.Experimental, Illicit
DextropropoxypheneButorphanol may decrease the analgesic activities of Dextropropoxyphene.Approved, Illicit, Withdrawn
DezocineButorphanol may decrease the analgesic activities of Dezocine.Approved
DiazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Diazepam.Approved, Illicit, Vet Approved
DicyclomineThe risk or severity of adverse effects can be increased when Dicyclomine is combined with Butorphanol.Approved
DiethylpropionDiethylpropion may increase the analgesic activities of Butorphanol.Approved, Illicit
DifenoxinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Difenoxin.Approved, Illicit
DihydrocodeineButorphanol may decrease the analgesic activities of Dihydrocodeine.Approved, Illicit
DihydroetorphineButorphanol may decrease the analgesic activities of Dihydroetorphine.Experimental, Illicit
DihydromorphineButorphanol may decrease the analgesic activities of Dihydromorphine.Experimental, Illicit
DimenhydrinateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Dimenhydrinate.Approved
DiphenhydramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Diphenhydramine.Approved
DiphenoxylateButorphanol may decrease the analgesic activities of Diphenoxylate.Approved, Illicit
DoramectinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Doramectin.Vet Approved
DoxepinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Doxepin.Approved
DoxylamineDoxylamine may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved, Vet Approved
DPDPEButorphanol may decrease the analgesic activities of DPDPE.Investigational
DronabinolDronabinol may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved, Illicit
DroperidolDroperidol may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved, Vet Approved
DrospirenoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Drospirenone.Approved
DrotebanolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Drotebanol.Experimental, Illicit
DuloxetineButorphanol may increase the serotonergic activities of Duloxetine.Approved
DyclonineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Dyclonine.Approved
EcgonineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ecgonine.Experimental, Illicit
ECGONINE METHYL ESTERThe risk or severity of adverse effects can be increased when Butorphanol is combined with ECGONINE METHYL ESTER.Experimental
EcopipamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ecopipam.Investigational
EfavirenzThe risk or severity of adverse effects can be increased when Butorphanol is combined with Efavirenz.Approved, Investigational
EfonidipineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Efonidipine.Approved
EluxadolineButorphanol may increase the constipating activities of Eluxadoline.Approved
EnfluraneThe risk or severity of adverse effects can be increased when Enflurane is combined with Butorphanol.Approved, Vet Approved
EntacaponeThe risk or severity of adverse effects can be increased when Butorphanol is combined with Entacapone.Approved, Investigational
EplerenoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Eplerenone.Approved
EscitalopramButorphanol may increase the serotonergic activities of Escitalopram.Approved, Investigational
EstazolamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Estazolam.Approved, Illicit
EszopicloneThe risk or severity of adverse effects can be increased when Eszopiclone is combined with Butorphanol.Approved
Etacrynic acidThe risk or severity of adverse effects can be increased when Butorphanol is combined with Etacrynic acid.Approved
EthanolButorphanol may increase the central nervous system depressant (CNS depressant) activities of Ethanol.Approved
EthchlorvynolThe risk or severity of adverse effects can be increased when Ethchlorvynol is combined with Butorphanol.Approved, Illicit, Withdrawn
EthopropazineThe risk or severity of adverse effects can be increased when Ethopropazine is combined with Butorphanol.Approved
EthosuximideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ethosuximide.Approved
EthotoinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ethotoin.Approved
EthoxzolamideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ethoxzolamide.Withdrawn
Ethyl carbamateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ethyl carbamate.Withdrawn
Ethyl loflazepateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ethyl loflazepate.Approved, Illicit
EthylmorphineButorphanol may decrease the analgesic activities of Ethylmorphine.Approved, Illicit
EtidocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Etidocaine.Approved
EtifoxineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Etifoxine.Withdrawn
EtizolamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Etizolam.Approved
EtomidateThe risk or severity of adverse effects can be increased when Etomidate is combined with Butorphanol.Approved
EtoperidoneButorphanol may increase the serotonergic activities of Etoperidone.Approved
EtorphineButorphanol may decrease the analgesic activities of Etorphine.Illicit, Vet Approved
EzogabineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ezogabine.Approved
FelbamateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Felbamate.Approved
FencamfamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fencamfamine.Approved, Illicit, Withdrawn
FentanylButorphanol may decrease the analgesic activities of Fentanyl.Approved, Illicit, Investigational, Vet Approved
FesoterodineThe risk or severity of adverse effects can be increased when Fesoterodine is combined with Butorphanol.Approved
FexofenadineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fexofenadine.Approved
FlibanserinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Flibanserin.Approved
FludiazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fludiazepam.Approved, Illicit
FlunarizineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Flunarizine.Approved
FlunitrazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Flunitrazepam.Approved, Illicit
FluoxetineButorphanol may increase the serotonergic activities of Fluoxetine.Approved, Vet Approved
FlupentixolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Flupentixol.Approved, Withdrawn
FluphenazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fluphenazine.Approved
FlurazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Flurazepam.Approved, Illicit
FluspirileneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fluspirilene.Approved
Fluticasone PropionateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fluticasone Propionate.Approved
FluvoxamineThe risk or severity of adverse effects can be increased when Fluvoxamine is combined with Butorphanol.Approved, Investigational
FosphenytoinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fosphenytoin.Approved
FospropofolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Fospropofol.Approved, Illicit
FurosemideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Furosemide.Approved, Vet Approved
GabapentinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Gabapentin.Approved, Investigational
gabapentin enacarbilThe risk or severity of adverse effects can be increased when Butorphanol is combined with gabapentin enacarbil.Approved
Gallamine TriethiodideThe risk or severity of adverse effects can be increased when Gallamine Triethiodide is combined with Butorphanol.Approved
Gamma Hydroxybutyric AcidThe risk or severity of adverse effects can be increased when Butorphanol is combined with Gamma Hydroxybutyric Acid.Approved, Illicit
GepironeThe risk or severity of adverse effects can be increased when Butorphanol is combined with Gepirone.Investigational
GlutethimideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Glutethimide.Approved, Illicit
GlycopyrroniumThe risk or severity of adverse effects can be increased when Glycopyrronium is combined with Butorphanol.Approved, Investigational, Vet Approved
GuanfacineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Guanfacine.Approved, Investigational
HalazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Halazepam.Approved, Illicit, Withdrawn
HaloperidolThe risk or severity of adverse effects can be increased when Haloperidol is combined with Butorphanol.Approved
HalothaneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Halothane.Approved, Vet Approved
HeroinButorphanol may decrease the analgesic activities of Heroin.Approved, Illicit
HexamethoniumThe risk or severity of adverse effects can be increased when Hexamethonium is combined with Butorphanol.Experimental
HexobarbitalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Hexobarbital.Approved
HomatropineThe risk or severity of adverse effects can be increased when Homatropine is combined with Butorphanol.Approved
HydrochlorothiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Hydrochlorothiazide.Approved, Vet Approved
HydrocodoneButorphanol may increase the central nervous system depressant (CNS depressant) activities of Hydrocodone.Approved, Illicit
HydroflumethiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Hydroflumethiazide.Approved
HydromorphoneButorphanol may decrease the analgesic activities of Hydromorphone.Approved, Illicit
Hydroxyamphetamine hydrobromideHydroxyamphetamine hydrobromide may increase the analgesic activities of Butorphanol.Approved
HydroxyzineHydroxyzine may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved
HyoscyamineThe risk or severity of adverse effects can be increased when Hyoscyamine is combined with Butorphanol.Approved
IloperidoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Iloperidone.Approved
ImipramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Imipramine.Approved
IndalpineButorphanol may increase the serotonergic activities of Indalpine.Investigational, Withdrawn
IndapamideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Indapamide.Approved
Ipratropium bromideThe risk or severity of adverse effects can be increased when Ipratropium bromide is combined with Butorphanol.Approved
IsofluraneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Isoflurane.Approved, Vet Approved
IsosorbideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Isosorbide.Approved
KetamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ketamine.Approved, Vet Approved
KetazolamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ketazolam.Approved
KetobemidoneButorphanol may decrease the analgesic activities of Ketobemidone.Approved
KW-3902The risk or severity of adverse effects can be increased when Butorphanol is combined with KW-3902.Investigational
LamotrigineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Lamotrigine.Approved, Investigational
LevetiracetamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Levetiracetam.Approved, Investigational
LevobupivacaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Levobupivacaine.Approved
LevocabastineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Levocabastine.Approved
LevocetirizineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Levocetirizine.Approved
LevodopaThe risk or severity of adverse effects can be increased when Butorphanol is combined with Levodopa.Approved
Levomethadyl AcetateButorphanol may decrease the analgesic activities of Levomethadyl Acetate.Approved
LevomilnacipranButorphanol may increase the serotonergic activities of Levomilnacipran.Approved
LevorphanolButorphanol may decrease the analgesic activities of Levorphanol.Approved
LidocaineThe risk or severity of adverse effects can be increased when Lidocaine is combined with Butorphanol.Approved, Vet Approved
LisdexamfetamineLisdexamfetamine may increase the analgesic activities of Butorphanol.Approved, Investigational
LithiumThe risk or severity of adverse effects can be increased when Butorphanol is combined with Lithium.Approved
LofentanilButorphanol may decrease the analgesic activities of Lofentanil.Illicit
LoratadineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Loratadine.Approved
LorazepamThe risk or severity of adverse effects can be increased when Lorazepam is combined with Butorphanol.Approved
LoxapineThe risk or severity of adverse effects can be increased when Loxapine is combined with Butorphanol.Approved
Lu AA21004The risk or severity of adverse effects can be increased when Butorphanol is combined with Lu AA21004.Investigational
LurasidoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Lurasidone.Approved
Magnesium SulfateMagnesium Sulfate may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved, Vet Approved
MannitolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Mannitol.Approved, Investigational
MaprotilineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Maprotiline.Approved
MecamylamineThe risk or severity of adverse effects can be increased when Mecamylamine is combined with Butorphanol.Approved
MeclizineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Meclizine.Approved
MedetomidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Medetomidine.Vet Approved
MelatoninThe risk or severity of adverse effects can be increased when Butorphanol is combined with Melatonin.Approved, Nutraceutical, Vet Approved
MelperoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Melperone.Approved
MephedroneMephedrone may increase the analgesic activities of Butorphanol.Investigational
MephentermineMephentermine may increase the analgesic activities of Butorphanol.Approved
MepivacaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Mepivacaine.Approved, Vet Approved
MeprobamateThe risk or severity of adverse effects can be increased when Meprobamate is combined with Butorphanol.Approved, Illicit
MersalylThe risk or severity of adverse effects can be increased when Butorphanol is combined with Mersalyl.Approved
MesoridazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Mesoridazine.Approved
MetaxaloneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Metaxalone.Approved
MethadoneButorphanol may decrease the analgesic activities of Methadone.Approved
Methadyl AcetateButorphanol may decrease the analgesic activities of Methadyl Acetate.Approved, Illicit
MethamphetamineMethamphetamine may increase the analgesic activities of Butorphanol.Approved, Illicit
MethanthelineThe risk or severity of adverse effects can be increased when Methantheline is combined with Butorphanol.Approved
MethapyrileneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methapyrilene.Withdrawn
MethaqualoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methaqualone.Illicit, Withdrawn
MethazolamideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methazolamide.Approved
MethocarbamolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methocarbamol.Approved, Vet Approved
MethohexitalThe risk or severity of adverse effects can be increased when Methohexital is combined with Butorphanol.Approved
MethotrimeprazineButorphanol may increase the central nervous system depressant (CNS depressant) activities of Methotrimeprazine.Approved
MethoxyfluraneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methoxyflurane.Approved, Vet Approved
MethsuximideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methsuximide.Approved
MethyclothiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methyclothiazide.Approved
Methylene blueMethylene blue may increase the hypotensive activities of Butorphanol.Investigational
MethylnaltrexoneThe risk or severity of adverse effects can be increased when Methylnaltrexone is combined with Butorphanol.Approved
MethylphenobarbitalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Methylphenobarbital.Approved
MetixeneThe risk or severity of adverse effects can be increased when Metixene is combined with Butorphanol.Approved
MetolazoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Metolazone.Approved
MetyrosineButorphanol may increase the sedative activities of Metyrosine.Approved
MidazolamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Midazolam.Approved, Illicit
MilnacipranButorphanol may increase the serotonergic activities of Milnacipran.Approved
MinocyclineMinocycline may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved, Investigational
MirtazapineButorphanol may increase the central nervous system depressant (CNS depressant) activities of Mirtazapine.Approved
MMDAMMDA may increase the analgesic activities of Butorphanol.Experimental, Illicit
MolindoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Molindone.Approved
MoricizineMoricizine may increase the hypotensive activities of Butorphanol.Approved, Withdrawn
MorphineButorphanol may decrease the analgesic activities of Morphine.Approved, Investigational
N-butylscopolammonium bromideThe risk or severity of adverse effects can be increased when N-butylscopolammonium bromide is combined with Butorphanol.Vet Approved
NabiloneNabilone may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved, Investigational
NalbuphineButorphanol may decrease the analgesic activities of Nalbuphine.Approved
NaloxegolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Naloxegol.Approved
NaltrexoneThe therapeutic efficacy of Butorphanol can be decreased when used in combination with Naltrexone.Approved, Investigational, Vet Approved
NefazodoneButorphanol may increase the serotonergic activities of Nefazodone.Approved, Withdrawn
NitrazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Nitrazepam.Approved
Nitrous oxideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Nitrous oxide.Approved, Vet Approved
NormethadoneButorphanol may decrease the analgesic activities of Normethadone.Approved, Illicit
NortriptylineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Nortriptyline.Approved
NVA237The risk or severity of adverse effects can be increased when NVA237 is combined with Butorphanol.Investigational
OlanzapineThe risk or severity of adverse effects can be increased when Olanzapine is combined with Butorphanol.Approved, Investigational
OlopatadineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Olopatadine.Approved
OndansetronThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ondansetron.Approved
OpiumButorphanol may decrease the analgesic activities of Opium.Approved, Illicit
OrphenadrineButorphanol may increase the central nervous system depressant (CNS depressant) activities of Orphenadrine.Approved
OsanetantThe risk or severity of adverse effects can be increased when Butorphanol is combined with Osanetant.Investigational
OxazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Oxazepam.Approved
OxetacaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Oxetacaine.Investigational
OxprenololThe risk or severity of adverse effects can be increased when Butorphanol is combined with Oxprenolol.Approved
OxybuprocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Oxybuprocaine.Approved
OxybutyninThe risk or severity of adverse effects can be increased when Oxybutynin is combined with Butorphanol.Approved, Investigational
OxycodoneButorphanol may decrease the analgesic activities of Oxycodone.Approved, Illicit, Investigational
OxymorphoneButorphanol may decrease the analgesic activities of Oxymorphone.Approved, Investigational, Vet Approved
OxyphenoniumThe risk or severity of adverse effects can be increased when Oxyphenonium is combined with Butorphanol.Approved
PaliperidoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Paliperidone.Approved
PancuroniumThe risk or severity of adverse effects can be increased when Pancuronium is combined with Butorphanol.Approved
ParaldehydeButorphanol may increase the central nervous system depressant (CNS depressant) activities of Paraldehyde.Approved
ParoxetineButorphanol may increase the serotonergic activities of Paroxetine.Approved, Investigational
PegvisomantThe therapeutic efficacy of Pegvisomant can be decreased when used in combination with Butorphanol.Approved
PentazocineButorphanol may decrease the analgesic activities of Pentazocine.Approved, Vet Approved
PentobarbitalThe risk or severity of adverse effects can be increased when Pentobarbital is combined with Butorphanol.Approved, Vet Approved
PentoliniumThe risk or severity of adverse effects can be increased when Pentolinium is combined with Butorphanol.Approved
PerampanelPerampanel may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved
PerazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Perazine.Investigational
PerospironeThe risk or severity of adverse effects can be increased when Butorphanol is combined with Perospirone.Approved
PerphenazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Perphenazine.Approved
PethidineButorphanol may decrease the analgesic activities of Pethidine.Approved
PhenobarbitalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Phenobarbital.Approved
PhenoxyethanolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Phenoxyethanol.Approved
PhenterminePhentermine may increase the analgesic activities of Butorphanol.Approved, Illicit
PhenytoinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Phenytoin.Approved, Vet Approved
PimozideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pimozide.Approved
PipamperoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pipamperone.Approved
PipecuroniumThe risk or severity of adverse effects can be increased when Pipecuronium is combined with Butorphanol.Approved
PipotiazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pipotiazine.Approved
PirenzepineThe risk or severity of adverse effects can be increased when Pirenzepine is combined with Butorphanol.Approved
PiretanideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Piretanide.Experimental
PiritramideButorphanol may decrease the analgesic activities of Piritramide.Investigational
PizotifenThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pizotifen.Approved
PolythiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Polythiazide.Approved
PomalidomideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pomalidomide.Approved
PotassiumThe risk or severity of adverse effects can be increased when Butorphanol is combined with Potassium.Approved
Potassium CitrateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Potassium Citrate.Approved, Vet Approved
PramipexoleButorphanol may increase the sedative activities of Pramipexole.Approved, Investigational
PramocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pramocaine.Approved
PrazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Prazepam.Approved, Illicit
PregabalinThe risk or severity of adverse effects can be increased when Pregabalin is combined with Butorphanol.Approved, Illicit, Investigational
PregnanoloneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Pregnanolone.Investigational
PrilocaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Prilocaine.Approved
PrimidoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Primidone.Approved, Vet Approved
ProcaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Procaine.Approved, Investigational, Vet Approved
ProchlorperazineThe risk or severity of adverse effects can be increased when Prochlorperazine is combined with Butorphanol.Approved, Vet Approved
ProcyclidineThe risk or severity of adverse effects can be increased when Procyclidine is combined with Butorphanol.Approved
PromazineThe risk or severity of adverse effects can be increased when Promazine is combined with Butorphanol.Approved, Vet Approved
PromethazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Promethazine.Approved
PropanthelineThe risk or severity of adverse effects can be increased when Propantheline is combined with Butorphanol.Approved
ProparacaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Proparacaine.Approved, Vet Approved
PropiopromazinePropiopromazine may increase the hypotensive activities of Butorphanol.Vet Approved
PropiverineThe risk or severity of adverse effects can be increased when Propiverine is combined with Butorphanol.Investigational
PropofolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Propofol.Approved, Investigational, Vet Approved
PropoxycaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Propoxycaine.Approved
ProtriptylineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Protriptyline.Approved
PSD502The risk or severity of adverse effects can be increased when Butorphanol is combined with PSD502.Investigational
PseudoephedrinePseudoephedrine may increase the analgesic activities of Butorphanol.Approved
QuazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Quazepam.Approved, Illicit
QuetiapineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Quetiapine.Approved
QuinethazoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Quinethazone.Approved
QuinidineThe risk or severity of adverse effects can be increased when Quinidine is combined with Butorphanol.Approved
RacloprideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Raclopride.Investigational
RamelteonThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ramelteon.Approved, Investigational
RamosetronButorphanol may increase the constipating activities of Ramosetron.Approved
RemifentanilButorphanol may decrease the analgesic activities of Remifentanil.Approved
RemoxiprideThe risk or severity of adverse effects can be increased when Remoxipride is combined with Butorphanol.Approved, Withdrawn
ReserpineThe risk or severity of adverse effects can be increased when Reserpine is combined with Butorphanol.Approved
RisperidoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Risperidone.Approved, Investigational
RitanserinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ritanserin.Investigational
RitobegronRitobegron may increase the analgesic activities of Butorphanol.Investigational
RolofyllineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Rolofylline.Investigational
RomifidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Romifidine.Vet Approved
RopiniroleButorphanol may increase the sedative activities of Ropinirole.Approved, Investigational
RopivacaineThe risk or severity of adverse effects can be increased when Ropivacaine is combined with Butorphanol.Approved
RotigotineButorphanol may increase the sedative activities of Rotigotine.Approved
RufinamideThe risk or severity of adverse effects can be increased when Rufinamide is combined with Butorphanol.Approved
S-EthylisothioureaThe risk or severity of adverse effects can be increased when Butorphanol is combined with S-Ethylisothiourea.Experimental
Sage 547The risk or severity of adverse effects can be increased when Butorphanol is combined with Sage 547.Investigational
ScopolamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Scopolamine.Approved
Scopolamine butylbromideThe risk or severity of adverse effects can be increased when Scopolamine butylbromide is combined with Butorphanol.Approved
SecobarbitalThe risk or severity of adverse effects can be increased when Secobarbital is combined with Butorphanol.Approved, Vet Approved
SertindoleThe risk or severity of adverse effects can be increased when Butorphanol is combined with Sertindole.Approved, Withdrawn
SertralineButorphanol may increase the serotonergic activities of Sertraline.Approved
SevofluraneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Sevoflurane.Approved, Vet Approved
Sodium oxybateSodium oxybate may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved
SolifenacinThe risk or severity of adverse effects can be increased when Solifenacin is combined with Butorphanol.Approved
SpironolactoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Spironolactone.Approved
StiripentolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Stiripentol.Approved
SuccinylcholineSuccinylcholine may increase the bradycardic activities of Butorphanol.Approved
SufentanilButorphanol may decrease the analgesic activities of Sufentanil.Approved, Investigational
SulpirideThe risk or severity of adverse effects can be increased when Sulpiride is combined with Butorphanol.Approved
SuvorexantButorphanol may increase the central nervous system depressant (CNS depressant) activities of Suvorexant.Approved
TandospironeThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tandospirone.Investigational
TapentadolTapentadol may increase the central nervous system depressant (CNS depressant) activities of Butorphanol.Approved
TasimelteonThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tasimelteon.Approved
TemazepamThe risk or severity of adverse effects can be increased when Temazepam is combined with Butorphanol.Approved
TetrabenazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tetrabenazine.Approved
TetracaineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tetracaine.Approved, Vet Approved
TetrodotoxinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tetrodotoxin.Investigational
ThalidomideButorphanol may increase the central nervous system depressant (CNS depressant) activities of Thalidomide.Approved, Investigational, Withdrawn
TheobromineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Theobromine.Approved
ThiamylalThe risk or severity of adverse effects can be increased when Butorphanol is combined with Thiamylal.Approved, Vet Approved
ThiethylperazineThiethylperazine may increase the hypotensive activities of Butorphanol.Withdrawn
ThiopentalThe risk or severity of adverse effects can be increased when Thiopental is combined with Butorphanol.Approved, Vet Approved
ThioridazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Thioridazine.Approved
ThiothixeneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Thiothixene.Approved
TiagabineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tiagabine.Approved
TiaprideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tiapride.Investigational
TicrynafenThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ticrynafen.Withdrawn
TiletamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tiletamine.Vet Approved
TiotropiumThe risk or severity of adverse effects can be increased when Tiotropium is combined with Butorphanol.Approved
TizanidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tizanidine.Approved
TolcaponeThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tolcapone.Approved, Withdrawn
TolterodineThe risk or severity of adverse effects can be increased when Tolterodine is combined with Butorphanol.Approved, Investigational
TolvaptanThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tolvaptan.Approved
TopiramateThe risk or severity of adverse effects can be increased when Butorphanol is combined with Topiramate.Approved
TorasemideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Torasemide.Approved
TramadolButorphanol may decrease the analgesic activities of Tramadol.Approved, Investigational
Trans-2-PhenylcyclopropylamineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Trans-2-Phenylcyclopropylamine.Experimental
TranylcypromineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Tranylcypromine.Approved
TrazodoneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Trazodone.Approved, Investigational
TriamtereneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Triamterene.Approved
TriazolamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Triazolam.Approved
TrichlormethiazideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Trichlormethiazide.Approved, Vet Approved
TrifluoperazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Trifluoperazine.Approved
TriflupromazineThe risk or severity of adverse effects can be increased when Triflupromazine is combined with Butorphanol.Approved, Vet Approved
TrihexyphenidylThe risk or severity of adverse effects can be increased when Trihexyphenidyl is combined with Butorphanol.Approved
TrimethaphanThe risk or severity of adverse effects can be increased when Trimethaphan is combined with Butorphanol.Approved
TrimipramineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Trimipramine.Approved
TriprolidineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Triprolidine.Approved
TropicamideThe risk or severity of adverse effects can be increased when Tropicamide is combined with Butorphanol.Approved
TrospiumThe risk or severity of adverse effects can be increased when Trospium is combined with Butorphanol.Approved
TubocurarineThe risk or severity of adverse effects can be increased when Tubocurarine is combined with Butorphanol.Approved
Uc1010The risk or severity of adverse effects can be increased when Butorphanol is combined with Uc1010.Investigational
UlaritideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ularitide.Investigational
UmeclidiniumThe risk or severity of adverse effects can be increased when Umeclidinium is combined with Butorphanol.Approved
Valproic AcidThe risk or severity of adverse effects can be increased when Valproic Acid is combined with Butorphanol.Approved, Investigational
VecuroniumThe risk or severity of adverse effects can be increased when Vecuronium is combined with Butorphanol.Approved
VenlafaxineButorphanol may increase the serotonergic activities of Venlafaxine.Approved
VigabatrinThe risk or severity of adverse effects can be increased when Butorphanol is combined with Vigabatrin.Approved
VortioxetineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Vortioxetine.Approved
XylazineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Xylazine.Vet Approved
ZaleplonThe risk or severity of adverse effects can be increased when Butorphanol is combined with Zaleplon.Approved, Illicit, Investigational
ZiconotideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Ziconotide.Approved
ZimelidineButorphanol may increase the serotonergic activities of Zimelidine.Withdrawn
ZiprasidoneThe risk or severity of adverse effects can be increased when Ziprasidone is combined with Butorphanol.Approved
ZolazepamThe risk or severity of adverse effects can be increased when Butorphanol is combined with Zolazepam.Vet Approved
ZolpidemButorphanol may increase the central nervous system depressant (CNS depressant) activities of Zolpidem.Approved
ZonisamideThe risk or severity of adverse effects can be increased when Butorphanol is combined with Zonisamide.Approved, Investigational
ZopicloneThe risk or severity of adverse effects can be increased when Butorphanol is combined with Zopiclone.Approved
ZotepineThe risk or severity of adverse effects can be increased when Butorphanol is combined with Zotepine.Approved
ZuclopenthixolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Zuclopenthixol.Approved, Investigational
Food Interactions
  • Avoid alcohol.
References
Synthesis Reference

Monkovic, I. and Conway, T.T.; U.S. Patent 3,775,414; November 27,1973; Monkovic, I.,Wong, H. and Lim, G.; U.S. Patent 3,980,641; September 14, 1976; Pachter, IJ., Belleau, B.R. and Monkovic, I.; U.S. Patent 3,819,635; June 25,1974; and Lim, G. and Hooper, J.W.; U.S. Patent 4,017,497; April 12,1977; all assigned to Bristol-Myers Company.

General References
  1. Gear RW, Miaskowski C, Gordon NC, Paul SM, Heller PH, Levine JD: The kappa opioid nalbuphine produces gender- and dose-dependent analgesia and antianalgesia in patients with postoperative pain. Pain. 1999 Nov;83(2):339-45. [PubMed:10534607 ]
  2. Fan LW, Tanaka S, Tien LT, Ma T, Rockhold RW, Ho IK: Withdrawal from dependence upon butorphanol uniquely increases kappa(1)-opioid receptor binding in the rat brain. Brain Res Bull. 2002 Jun;58(2):149-60. [PubMed:12127012 ]
External Links
ATC CodesN02AF01
AHFS Codes
  • 28:08.12
PDB EntriesNot Available
FDA labelDownload (320 KB)
MSDSDownload (60.6 KB)
ADMET
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.9798
Blood Brain Barrier+0.9463
Caco-2 permeable+0.6844
P-glycoprotein substrateSubstrate0.8494
P-glycoprotein inhibitor IInhibitor0.5
P-glycoprotein inhibitor IIInhibitor0.5667
Renal organic cation transporterInhibitor0.6508
CYP450 2C9 substrateNon-substrate0.8248
CYP450 2D6 substrateSubstrate0.509
CYP450 3A4 substrateSubstrate0.5842
CYP450 1A2 substrateNon-inhibitor0.6532
CYP450 2C9 inhibitorNon-inhibitor0.9094
CYP450 2D6 inhibitorInhibitor0.6572
CYP450 2C19 inhibitorNon-inhibitor0.8456
CYP450 3A4 inhibitorNon-inhibitor0.8744
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.9017
Ames testNon AMES toxic0.7587
CarcinogenicityNon-carcinogens0.9573
BiodegradationNot ready biodegradable0.9368
Rat acute toxicity2.6466 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.5378
hERG inhibition (predictor II)Inhibitor0.5983
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397 )
Pharmacoeconomics
Manufacturers
  • Bedford laboratories div ben venue laboratories inc
  • Claris lifesciences ltd
  • Hikma farmaceutica (portugal) sa
  • Hikma farmaceutica sa
  • Hospira inc
  • Apothecon inc div bristol myers squibb
  • Mylan pharmaceuticals inc
  • Novex pharma
  • Roxane laboratories inc
  • Bristol myers squibb co pharmaceutical research institute
Packagers
Dosage forms
FormRouteStrength
SolutionNasal10 mg
InjectionIntramuscular; Intravenous1 mg/mL
InjectionIntramuscular; Intravenous2 mg/mL
Injection, solutionIntramuscular; Intravenous1 mg/mL
Injection, solutionIntramuscular; Intravenous2 mg/mL
SolutionNasal10 mg/mL
SprayNasal10 mg/mL
Spray, meteredNasal10 mg/mL
SprayNasal10 mg
Aerosol, metered; liquidNasal10 mg
Prices
Unit descriptionCostUnit
Butorphanol Tartrate 10 mg/ml Solution 2.5ml Bottle56.99USD bottle
Butorphanol 10 mg/ml spray39.63USD ml
Stadol 2 mg/ml vial10.11USD ml
Butorphanol 2 mg/ml vial7.2USD ml
Butorphanol 1 mg/ml vial3.6USD ml
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
PatentsNot Available
Properties
StateSolid
Experimental Properties
PropertyValueSource
melting point272-274Monkovic, I. and Conway, T.T.; U.S. Patent 3,775,414; November 27,1973; Monkovic, I.,Wong, H. and Lim, G.; U.S. Patent 3,980,641; September 14, 1976; Pachter, IJ., Belleau, B.R. and Monkovic, I.; U.S. Patent 3,819,635; June 25,1974; and Lim, G. and Hooper, J.W.; U.S. Patent 4,017,497; April 12,1977; all assigned to Bristol-Myers Company.
water solubilityModerateNot Available
logP3.3Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.16 mg/mLALOGPS
logP3.65ALOGPS
logP2.89ChemAxon
logS-3.3ALOGPS
pKa (Strongest Acidic)9.86ChemAxon
pKa (Strongest Basic)10.7ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area43.7 Å2ChemAxon
Rotatable Bond Count2ChemAxon
Refractivity95.92 m3·mol-1ChemAxon
Polarizability37.94 Å3ChemAxon
Number of Rings5ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Mass Spec (NIST)Not Available
SpectraNot Available
Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as morphinans. These are polycyclic compounds with a four-ring skeleton with three condensed six-member rings forming a partially hydrogenated phenanthrene moiety, one of which is aromatic while the two others are alicyclic.
KingdomOrganic compounds
Super ClassAlkaloids and derivatives
ClassMorphinans
Sub ClassNot Available
Direct ParentMorphinans
Alternative Parents
Substituents
  • Morphinan
  • Benzylisoquinoline
  • Phenanthrene
  • Benzazocine
  • Tetralin
  • Aralkylamine
  • Benzenoid
  • Piperidine
  • Tertiary alcohol
  • Cyclic alcohol
  • Tertiary aliphatic amine
  • Tertiary amine
  • 1,2-aminoalcohol
  • Azacycle
  • Organoheterocyclic compound
  • Hydrocarbon derivative
  • Organooxygen compound
  • Organonitrogen compound
  • Amine
  • Alcohol
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External DescriptorsNot Available

Targets

Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
agonist
General Function:
Opioid receptor activity
Specific Function:
G-protein coupled opioid receptor that functions as receptor for endogenous alpha-neoendorphins and dynorphins, but has low affinity for beta-endorphins. Also functions as receptor for various synthetic opioids and for the psychoactive diterpene salvinorin A. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates th...
Gene Name:
OPRK1
Uniprot ID:
P41145
Molecular Weight:
42644.665 Da
References
  1. Vivian JA, DeYoung MB, Sumpter TL, Traynor JR, Lewis JW, Woods JH: kappa-Opioid receptor effects of butorphanol in rhesus monkeys. J Pharmacol Exp Ther. 1999 Jul;290(1):259-65. [PubMed:10381785 ]
  2. Park Y, Jang CG, Ho IK, Ko KH: kappa-opioid agonist stimulated regional distribution of [(35)S]GTPgammas binding in butorphanol continuously infused rat. Brain Res Bull. 2000 May 1;52(1):17-20. [PubMed:10779697 ]
  3. Fan LW, Tanaka S, Tien LT, Ma T, Rockhold RW, Ho IK: Withdrawal from dependence upon butorphanol uniquely increases kappa(1)-opioid receptor binding in the rat brain. Brain Res Bull. 2002 Jun;58(2):149-60. [PubMed:12127012 ]
  4. Fan LW, Tanaka S, Park Y, Sasaki K, Ma T, Tien LT, Rockhold RW, Ho IK: Butorphanol dependence and withdrawal decrease hippocampal kappa 2-opioid receptor binding. Brain Res. 2002 Dec 27;958(2):277-90. [PubMed:12470863 ]
  5. Commiskey S, Fan LW, Ho IK, Rockhold RW: Butorphanol: effects of a prototypical agonist-antagonist analgesic on kappa-opioid receptors. J Pharmacol Sci. 2005 Jun;98(2):109-16. Epub 2005 Jun 8. [PubMed:15942128 ]
  6. Picker MJ, Benyas S, Horwitz JA, Thompson K, Mathewson C, Smith MA: Discriminative stimulus effects of butorphanol: influence of training dose on the substitution patterns produced by Mu, Kappa and Delta opioid agonists. J Pharmacol Exp Ther. 1996 Dec;279(3):1130-41. [PubMed:8968334 ]
  7. Wakabayashi H, Tokuyama S, Ho IK: Simultaneous measurement of biogenic amines and their metabolites in rat brain regions after acute administration of and abrupt withdrawal from butorphanol or morphine. Neurochem Res. 1995 Oct;20(10):1179-85. [PubMed:8746803 ]
  8. Narita M, Feng Y, Makimura M, Hoskins B, Ho IK: Repeated administration of opioids alters characteristics of membrane-bound phorbol ester binding in rat brain. Eur J Pharmacol. 1994 Dec 27;271(2-3):547-50. [PubMed:7705457 ]
  9. Ohta S, Niwa M, Nozaki M, Tsurumi K, Shimonaka H, Tanahashi T, Uematsu H, Yamamoto M, Fujimura H: [Kappa-type opioid receptor in human placental membrane]. Masui. 1989 Oct;38(10):1293-300. [PubMed:2555580 ]
  10. Walsh SL, Chausmer AE, Strain EC, Bigelow GE: Evaluation of the mu and kappa opioid actions of butorphanol in humans through differential naltrexone blockade. Psychopharmacology (Berl). 2008 Jan;196(1):143-55. Epub 2007 Oct 2. [PubMed:17909753 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
agonist
General Function:
Opioid receptor activity
Specific Function:
G-protein coupled receptor that functions as receptor for endogenous enkephalins and for a subset of other opioids. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors, such as adenylate cyclase. Signaling leads to the inhibition of adenylate cyclase activity. Inhibits neurot...
Gene Name:
OPRD1
Uniprot ID:
P41143
Molecular Weight:
40368.235 Da
References
  1. Fan LW, Tanaka S, Tien LT, Ma T, Rockhold RW, Ho IK: Withdrawal from dependence upon butorphanol uniquely increases kappa(1)-opioid receptor binding in the rat brain. Brain Res Bull. 2002 Jun;58(2):149-60. [PubMed:12127012 ]
  2. Fan LW, Tanaka S, Park Y, Sasaki K, Ma T, Tien LT, Rockhold RW, Ho IK: Butorphanol dependence and withdrawal decrease hippocampal kappa 2-opioid receptor binding. Brain Res. 2002 Dec 27;958(2):277-90. [PubMed:12470863 ]
  3. Commiskey S, Fan LW, Ho IK, Rockhold RW: Butorphanol: effects of a prototypical agonist-antagonist analgesic on kappa-opioid receptors. J Pharmacol Sci. 2005 Jun;98(2):109-16. Epub 2005 Jun 8. [PubMed:15942128 ]
  4. Picker MJ, Benyas S, Horwitz JA, Thompson K, Mathewson C, Smith MA: Discriminative stimulus effects of butorphanol: influence of training dose on the substitution patterns produced by Mu, Kappa and Delta opioid agonists. J Pharmacol Exp Ther. 1996 Dec;279(3):1130-41. [PubMed:8968334 ]
  5. Wakabayashi H, Tokuyama S, Ho IK: Simultaneous measurement of biogenic amines and their metabolites in rat brain regions after acute administration of and abrupt withdrawal from butorphanol or morphine. Neurochem Res. 1995 Oct;20(10):1179-85. [PubMed:8746803 ]
  6. Narita M, Feng Y, Makimura M, Hoskins B, Ho IK: Repeated administration of opioids alters characteristics of membrane-bound phorbol ester binding in rat brain. Eur J Pharmacol. 1994 Dec 27;271(2-3):547-50. [PubMed:7705457 ]
  7. Walsh SL, Chausmer AE, Strain EC, Bigelow GE: Evaluation of the mu and kappa opioid actions of butorphanol in humans through differential naltrexone blockade. Psychopharmacology (Berl). 2008 Jan;196(1):143-55. Epub 2007 Oct 2. [PubMed:17909753 ]
  8. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
partial antagonist
General Function:
Voltage-gated calcium channel activity
Specific Function:
Receptor for endogenous opioids such as beta-endorphin and endomorphin. Receptor for natural and synthetic opioids including morphine, heroin, DAMGO, fentanyl, etorphine, buprenorphin and methadone. Agonist binding to the receptor induces coupling to an inactive GDP-bound heterotrimeric G-protein complex and subsequent exchange of GDP for GTP in the G-protein alpha subunit leading to dissociati...
Gene Name:
OPRM1
Uniprot ID:
P35372
Molecular Weight:
44778.855 Da
References
  1. Vivian JA, DeYoung MB, Sumpter TL, Traynor JR, Lewis JW, Woods JH: kappa-Opioid receptor effects of butorphanol in rhesus monkeys. J Pharmacol Exp Ther. 1999 Jul;290(1):259-65. [PubMed:10381785 ]
  2. Fan LW, Tanaka S, Tien LT, Ma T, Rockhold RW, Ho IK: Withdrawal from dependence upon butorphanol uniquely increases kappa(1)-opioid receptor binding in the rat brain. Brain Res Bull. 2002 Jun;58(2):149-60. [PubMed:12127012 ]
  3. Fan LW, Tanaka S, Park Y, Sasaki K, Ma T, Tien LT, Rockhold RW, Ho IK: Butorphanol dependence and withdrawal decrease hippocampal kappa 2-opioid receptor binding. Brain Res. 2002 Dec 27;958(2):277-90. [PubMed:12470863 ]
  4. Commiskey S, Fan LW, Ho IK, Rockhold RW: Butorphanol: effects of a prototypical agonist-antagonist analgesic on kappa-opioid receptors. J Pharmacol Sci. 2005 Jun;98(2):109-16. Epub 2005 Jun 8. [PubMed:15942128 ]
  5. Picker MJ, Benyas S, Horwitz JA, Thompson K, Mathewson C, Smith MA: Discriminative stimulus effects of butorphanol: influence of training dose on the substitution patterns produced by Mu, Kappa and Delta opioid agonists. J Pharmacol Exp Ther. 1996 Dec;279(3):1130-41. [PubMed:8968334 ]
  6. Wakabayashi H, Tokuyama S, Ho IK: Simultaneous measurement of biogenic amines and their metabolites in rat brain regions after acute administration of and abrupt withdrawal from butorphanol or morphine. Neurochem Res. 1995 Oct;20(10):1179-85. [PubMed:8746803 ]
  7. Picker MJ: Discriminative stimulus effects of the mixed-opioid agonist/antagonist dezocine: cross-substitution by mu and delta opioid agonists. J Pharmacol Exp Ther. 1997 Dec;283(3):1009-17. [PubMed:9399970 ]
  8. Narita M, Feng Y, Makimura M, Hoskins B, Ho IK: Repeated administration of opioids alters characteristics of membrane-bound phorbol ester binding in rat brain. Eur J Pharmacol. 1994 Dec 27;271(2-3):547-50. [PubMed:7705457 ]
  9. Walsh SL, Chausmer AE, Strain EC, Bigelow GE: Evaluation of the mu and kappa opioid actions of butorphanol in humans through differential naltrexone blockade. Psychopharmacology (Berl). 2008 Jan;196(1):143-55. Epub 2007 Oct 2. [PubMed:17909753 ]
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Drug created on June 13, 2005 07:24 / Updated on August 17, 2016 12:23