Please Wait
Applying Filters...
Menu
$ API Ref.Price (USD/KG) : 130,329Xls
2D Structure
Also known as: 548-73-2, Droleptan, Inapsine, Dehydrobenzperidol, Dridol, Properidol
Molecular Formula
C22H22FN3O2
Molecular Weight
379.4  g/mol
InChI Key
RMEDXOLNCUSCGS-UHFFFAOYSA-N
FDA UNII
O9U0F09D5X

A butyrophenone with general properties similar to those of HALOPERIDOL. It is used in conjunction with an opioid analgesic such as FENTANYL to maintain the patient in a calm state of neuroleptanalgesia with indifference to surroundings but still able to cooperate with the surgeon. It is also used as a premedicant, as an antiemetic, and for the control of agitation in acute psychoses. (From Martindale, The Extra Pharmacopoeia, 29th ed, p593)
Droperidol is a Dopamine-2 Receptor Antagonist. The mechanism of action of droperidol is as a Dopamine D2 Antagonist.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
3-[1-[4-(4-fluorophenyl)-4-oxobutyl]-3,6-dihydro-2H-pyridin-4-yl]-1H-benzimidazol-2-one
2.1.2 InChI
InChI=1S/C22H22FN3O2/c23-17-9-7-16(8-10-17)21(27)6-3-13-25-14-11-18(12-15-25)26-20-5-2-1-4-19(20)24-22(26)28/h1-2,4-5,7-11H,3,6,12-15H2,(H,24,28)
2.1.3 InChI Key
RMEDXOLNCUSCGS-UHFFFAOYSA-N
2.1.4 Canonical SMILES
C1CN(CC=C1N2C3=CC=CC=C3NC2=O)CCCC(=O)C4=CC=C(C=C4)F
2.2 Other Identifiers
2.2.1 UNII
O9U0F09D5X
2.3 Synonyms
2.3.1 MeSH Synonyms

1. Dehidrobenzperidol

2. Dehydrobenzperidol

3. Droleptan

4. Inapsine

2.3.2 Depositor-Supplied Synonyms

1. 548-73-2

2. Droleptan

3. Inapsine

4. Dehydrobenzperidol

5. Dridol

6. Properidol

7. Sintodril

8. Sintosian

9. Inapsin

10. Vetkalm

11. Halkan

12. Deidrobenzperidolo

13. Inopsin

14. Innovar

15. Mcn-jr-4749

16. Inappin

17. Innovan

18. Inoval

19. Dehidrobenzperidol

20. Droperidolum

21. Droperidolo

22. Leptofen

23. Thalamanol

24. Thalamonal

25. Innovar-vet

26. Dihidrobenzperidol

27. R-4749

28. Mcn-jr 4749

29. Component Of Innovar

30. R 4749

31. Nsc 169874

32. 1-(1-(3-(p-fluorobenzoyl)propyl)-1,2,3,6-tetrahydro-4-pyridyl)-2-benzimidazolinone

33. 3-[1-[4-(4-fluorophenyl)-4-oxobutyl]-3,6-dihydro-2h-pyridin-4-yl]-1h-benzimidazol-2-one

34. 1-(1-(4-(p-fluorophenyl)-4-oxobutyl)-1,2,3,6-tetrahydro-4-pyridyl)-2-benzimidazolinone

35. 1-{1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydropyridin-4-yl}-1,3-dihydro-2h-benzimidazol-2-one

36. Nsc-169874

37. Chembl1108

38. 1-[1-[3-(p-fluorobenzoyl)propyl]-1,2,3,6-tetrahydro-4-pyridyl]-2-benzimidazolinone

39. Mls000028671

40. Chebi:4717

41. O9u0f09d5x

42. 1-(1-(4-(4-fluorophenyl)-4-oxobutyl)-1,2,3,6-tetrahydropyridin-4-yl)-1h-benzo[d]imidazol-2(3h)-one

43. 2h-benzimidazol-2-one, 1-(1-(4-(4-fluorophenyl)-4-oxobutyl)-1,2,3,6-tetrahydro-4-pyridinyl)-1,3-dihydro-

44. 2h-benzimidazol-2-one, 1-[1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydro-4-pyridinyl]-1,3-dihydro-

45. Dehydrobenzoperidol

46. Nsc169874

47. 1-{1-[4-(4-fluoro-phenyl)-4-oxo-butyl]-1,2,3,6-tetrahydro-pyridin-4-yl}-1,3-dihydro-benzoimidazol-2-one

48. Ncgc00016504-01

49. Cas-548-73-2

50. Droperidolo [dcit]

51. Smr000058855

52. Dsstox_cid_2973

53. Dsstox_rid_76811

54. Dsstox_gsid_22973

55. 1-{1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydro-4-pyridinyl}-2,3-dihydro-1h-benzo[d]imidazol-2-one

56. Droperidolum [inn-latin]

57. Neurolidol

58. Ina.psi.ne

59. Ina.psi.n

60. Ino.psi.n

61. 1-[1-[4-(p-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydro-4-pyridyl]-2-benzimidazolinone

62. 2-benzimidazolinone, 1-(1-(3-(p-fluorobenzoyl)propyl)-1,2,3,6-tetrahydro-4-pyridyl)-

63. 2-benzimidazolinone, 1-[1-[3-(p-fluorobenzoyl)propyl]-1,2,3,6-tetrahydro-4-pyridyl]-

64. Droleptan (tn)

65. 1-(1-(4-(4-fluorophenyl)-4-oxobutyl)-1,2,3,6-tetrahydro-4-pyridinyl)-1,3-dihydro-2h-benzimidazol-2-one

66. 1-(1-(4-(4-fluorophenyl)-4-oxobutyl)-1,2,3,6-tetrahydropyridin-4-yl)-1,3-dihydro-2h-benzo[d]imidazol-2-one

67. 3-[1-[4-(4-fluorophenyl)-4-oxidanylidene-butyl]-2,3,4,5-tetrahydropyridin-4-yl]-1~{h}-benzimidazol-2-one

68. Ccris 9070

69. Hsdb 3320

70. R4749

71. Sr-05000001546

72. Inapsine (tn)

73. Einecs 208-957-8

74. Brn 0579168

75. Unii-o9u0f09d5x

76. Droperidol Usp

77. 1-(1-[3-(p-fluorobenzoyl)propyl]-1,2,3,6-tetrahydro-4-pyridyl)-2-benzimidazolinone

78. 1-[1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydro-4-pyridinyl]-1,3-dihydro-2h-benzimidazol-2-one

79. Prestwick_705

80. Mfcd00083290

81. Innovar (salt/mix)

82. Droperidol [usan:usp:inn:ban:jan]

83. Hs-0065

84. Leptanal (salt/mix)

85. Leptofen (salt/mix)

86. Spectrum_001220

87. Thalamonal (salt/mix)

88. Droperidol [mi]

89. Droperidol [inn]

90. Droperidol [jan]

91. Innovar-vet (salt/mix)

92. Opera_id_1751

93. Prestwick0_000360

94. Prestwick1_000360

95. Prestwick2_000360

96. Prestwick3_000360

97. Spectrum2_001386

98. Spectrum3_001426

99. Spectrum4_000407

100. Spectrum5_001305

101. Droperidol [hsdb]

102. Droperidol [usan]

103. Droperidol [vandf]

104. Droperidol [mart.]

105. Droperidol [usp-rs]

106. Droperidol [who-dd]

107. Schembl41426

108. Bspbio_000459

109. Bspbio_003132

110. Kbiogr_000674

111. Kbioss_001700

112. 5-24-02-00388 (beilstein Handbook Reference)

113. Mls000758203

114. Mls001148120

115. Mls001424134

116. Mls002153445

117. Divk1c_000103

118. Spectrum1501002

119. Spbio_001372

120. Spbio_002380

121. Bpbio1_000505

122. Droperidol (jp17/usp/inn)

123. Gtpl7172

124. Droperidol [green Book]

125. Droperidol [orange Book]

126. Dtxsid6022973

127. Hms500f05

128. Kbio1_000103

129. Kbio2_001700

130. Kbio2_004268

131. Kbio2_006836

132. Kbio3_002352

133. Droperidol [ep Monograph]

134. Ninds_000103

135. Droperidol [usp Monograph]

136. Hms1569g21

137. Hms1921b03

138. Hms2051l06

139. Hms2092o16

140. Hms2096g21

141. Hms2232m09

142. Hms3374b05

143. Hms3393l06

144. Hms3652m12

145. Hms3713g21

146. Hms3885n03

147. Pharmakon1600-01501002

148. Innovar Component Droperidol

149. Hy-b1240

150. Tox21_110461

151. Bdbm50017705

152. Ccg-39004

153. Nsc757819

154. S4096

155. Stl453109

156. Zinc19796080

157. Akos015960779

158. Droperidol Component Of Innovar

159. Tox21_110461_1

160. Ac-3537

161. Ccg-101004

162. Cs-4886

163. Db00450

164. Nc00254

165. Nsc-757819

166. 1-1-[3-(p-fluorobenzoyl)propyl]-1,2,3,6-tetrahydro-4-pyridyl-2-benzimidazolinone

167. 3-[1-[4-(4-fluorophenyl)-4-oxo-butyl]-3,6-dihydro-2h-pyridin-4-yl]-1h-benzimidazol-2-one

168. Idi1_000103

169. Ncgc00016504-02

170. Ncgc00016504-03

171. Ncgc00016504-04

172. Ncgc00016504-05

173. Ncgc00016504-06

174. Ncgc00016504-09

175. Ncgc00016504-17

176. Ncgc00094884-01

177. Ncgc00094884-02

178. Sbi-0051628.p002

179. Droperidol 1.0 Mg/ml In Dimethyl Sulfoxide

180. Ft-0655846

181. Sw220019-1

182. D00308

183. F17346

184. Ab00052191_04

185. Ab00052191_05

186. Wln: T56 Bmvnj D3- Dt6n Cutj A3vr Df

187. 548d732

188. A830387

189. L001006

190. Q174259

191. Sr-05000001546-1

192. Sr-05000001546-2

193. Sr-05000001546-3

194. W-105600

195. Brd-k97158071-001-05-8

196. Brd-k97158071-001-08-2

197. Droperidol, British Pharmacopoeia (bp) Reference Standard

198. Droperidol, European Pharmacopoeia (ep) Reference Standard

199. Droperidol, United States Pharmacopeia (usp) Reference Standard

200. 2h-benzimidazol-2-one,2,3,6-tetrahydro-4-pyridinyl]-1,3-dihydro-

201. 1-[1-[3-(p-fluorobenzoyl)propyl]-1,3,6-tetrahydro-4-pyridyl]-2-benzimidazolinone

202. 1-[1-[4-(p-fluorophenyl)-4-oxobutyl]-1,3,6-tetrahydro-4-pyridyl]-2-benzimidazolinone

203. 1-1-[3-(p-fluorobenzoyl)propyl]-1,3,6-tetrahydro-4-pyridyl-2-benzimidazolinone

204. Gamma-[4-(2-oxo-1-benzimidazolinyl)-1,2,3,6-tetrahydro-1-pyridyl]-p-fluorobutyrophenone

205. 1-(4-fluorophenyl)-4-[4-(2-hydroxy-1h-1,3-benzodiazol-1-yl)-1,2,3,6-tetrahydropyridin-1-yl]butan-1-one

206. 1-[1-[4-(4-fluorophenyl)-4-oxo-butyl]-3,6-dihydro-2h-pyridin-4-yl]-3h-benzoimidazol-2-one

207. 1-{1-[4-(4-chloro-phenyl)-4-oxo-butyl]-1,2,3,6-tetrahydro-pyridin-4-yl}-1,3-dihydro-benzoimidazol-2-one(droperidol)

208. 1-{1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydropyridin-4-yl}-2,3-dihydro-1h-1,3-benzodiazol-2-one

209. 1-{1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,5,6-tetrahydropyridin-4-yl] -1,3-dihydro-2h-benzimidazol}-2-one

210. 3-[1-[4-(4-fluorophenyl)-4-oxidanylidene-butyl]-3,6-dihydro-2h-pyridin-4-yl]-1h-benzimidazol-2-one

211. Uss

2.4 Create Date
2005-03-25
3 Chemical and Physical Properties
Molecular Weight 379.4 g/mol
Molecular Formula C22H22FN3O2
XLogP33.5
Hydrogen Bond Donor Count1
Hydrogen Bond Acceptor Count4
Rotatable Bond Count6
Exact Mass379.16960512 g/mol
Monoisotopic Mass379.16960512 g/mol
Topological Polar Surface Area52.6 Ų
Heavy Atom Count28
Formal Charge0
Complexity615
Isotope Atom Count0
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count0
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently Bonded Unit Count1
4 Drug and Medication Information
4.1 Drug Information
1 of 4  
Drug NameDroperidol
PubMed HealthDroperidol (Injection)
Drug ClassesAnesthetic Adjunct, Antiemetic
Drug LabelDroperidol Injection, USP, is a sterile, non-pyrogenic, aqueous solution for intravenous or intramuscular use only.Each mL contains:Droperidol.2.5 mgWater for Injection........q.s.p...
Active IngredientDroperidol
Dosage FormInjectable
RouteInjection
Strength2.5mg/ml
Market StatusPrescription
CompanyHospira; Luitpold

2 of 4  
Drug NameInapsine
PubMed HealthDroperidol (Injection)
Drug ClassesAnesthetic Adjunct, Antiemetic
Drug LabelINAPSINE contains droperidol, a neuroleptic (tranquilizer) agent. INAPSINE (droperidol) Injection is available in ampules and vials. Each milliliter contains 2.5 mg of droperidol in an aqueous solution adjusted to pH 3.4 0.4 with lactic acid. Dr...
Active IngredientDroperidol
Dosage FormInjectable
RouteInjection
Strength2.5mg/ml
Market StatusPrescription
CompanyAkorn

3 of 4  
Drug NameDroperidol
PubMed HealthDroperidol (Injection)
Drug ClassesAnesthetic Adjunct, Antiemetic
Drug LabelDroperidol Injection, USP, is a sterile, non-pyrogenic, aqueous solution for intravenous or intramuscular use only.Each mL contains:Droperidol.2.5 mgWater for Injection........q.s.p...
Active IngredientDroperidol
Dosage FormInjectable
RouteInjection
Strength2.5mg/ml
Market StatusPrescription
CompanyHospira; Luitpold

4 of 4  
Drug NameInapsine
PubMed HealthDroperidol (Injection)
Drug ClassesAnesthetic Adjunct, Antiemetic
Drug LabelINAPSINE contains droperidol, a neuroleptic (tranquilizer) agent. INAPSINE (droperidol) Injection is available in ampules and vials. Each milliliter contains 2.5 mg of droperidol in an aqueous solution adjusted to pH 3.4 0.4 with lactic acid. Dr...
Active IngredientDroperidol
Dosage FormInjectable
RouteInjection
Strength2.5mg/ml
Market StatusPrescription
CompanyAkorn

4.2 Therapeutic Uses

Adjuvants, Anesthesia; Antiemetics; Antipsychotic Agents; Dopamine Antagonists

National Library of Medicine's Medical Subject Headings online file (MeSH, 2009)


Droperidol Injection is indicated to reduce the incidence of nausea and vomiting associated with surgical and diagnostic procedures. /Included in US product label/

US Natl Inst Health; DailyMed. Current Medication Information for DROPERIDOL injection, solution (October 2011). Available from, as of June 25, 2012: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=147e033d-d997-4ef6-8bb5-a9ba372590b2


Droperidol has been used preoperatively and as an adjunct during induction and maintenance of general anesthesia and as an adjunct to regional anesthesia. /NOT included in US product labeling/

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2646


Droperidol has been used in combination with an opiate analgesic, such as fentanyl, for neuroleptanalgesia as an anxiolytic and to potentially increase the analgesic effect of the opiate. However, because of the risk of serious adverse effects, the manufacturer no longer recommends these uses. /NOT included in US product labeling/

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2646


For more Therapeutic Uses (Complete) data for DROPERIDOL (11 total), please visit the HSDB record page.


4.3 Drug Warning

/BOXED WARNING/ WARNING: Cases of QT prolongation and/or torsade de pointes have been reported in patients receiving droperidol at doses at or below recommended doses. Some cases have occurred in patients with no known risk factors for QT prolongation and some cases have been fatal. Due to its potential for serious proarrhythmic effects and death, droperidol should be reserved for use in the treatment of patients who fail to show an acceptable response to other adequate treatments, either because of insufficient effectiveness or the inability to achieve an effective dose due to intolerable adverse effects from those drugs. Cases of QT prolongation and serious arrhythmias (e.g., torsade de pointes) have been reported in patients treated with droperidol. Based on these reports, all patients should undergo a 12-lead ECG prior to administration of droperidol to determine if a prolonged QT interval (i.e., QTc greater than 440 msec for males or 450 msec for females) is present. If there is a prolonged QT interval, droperidol should NOT be administered. For patients in whom the potential benefit of droperidol treatment is felt to outweigh the risks of potentially serious arrhythmias, ECG monitoring should be performed prior to treatment and continued for 2-3 hours after completing treatment to monitor for arrhythmias. Droperidol is contraindicated in patients with known or suspected QT prolongation, including patients with congenital long QT syndrome. Droperidol should be administered with extreme caution to patients who may be at risk for development of prolonged QT syndrome (e.g., congestive heart failure, bradycardia, use of a diuretic, cardiac hypertrophy, hypokalemia, hypomagnesemia, or administration of other drugs known to increase the QT interval). Other risk factors may include age over 65 years, alcohol abuse, and use of agents such as benzodiazepines, volatile anesthetics, and IV opiates. Droperidol should be initiated at a low dose and adjusted upward, with caution, as needed to achieve the desired effect.

US Natl Inst Health; DailyMed. Current Medication Information for DROPERIDOL injection, solution (Updated: November 2013). Available from, as of April 24, 2015: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=147e033d-d997-4ef6-8bb5-a9ba372590b2


Droperidol should be administered with extreme caution to patients who may be at risk for development of prolonged QT syndrome (e.g., congestive heart failure, bradycardia, use of a diuretic, cardiac hypertrophy, hypokalemia, hypomagnesemia, or administration of other drugs known to increase the QT interval). Other risk factors may include age over 65 years, alcohol abuse, and use of agents such as benzodiazepines, volatile anesthetics, and IV opiates. Droperidol should be initiated at a low dose and adjusted upward, with caution, as needed to achieve the desired effect.

US Natl Inst Health; DailyMed. Current Medication Information for DROPERIDOL injection, solution (October 2011). Available from, as of June 25, 2012: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=147e033d-d997-4ef6-8bb5-a9ba372590b2


Droperidol is contraindicated in patients with known or suspected QT prolongation (i.e., QTc interval greater than 440 msec for males or 450 msec for females). This would include patients with congenital long QT syndrome.

US Natl Inst Health; DailyMed. Current Medication Information for DROPERIDOL injection, solution (October 2011). Available from, as of June 25, 2012: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=147e033d-d997-4ef6-8bb5-a9ba372590b2


Droperidol is contraindicated in patients with known hypersensitivity to the drug.

US Natl Inst Health; DailyMed. Current Medication Information for DROPERIDOL injection, solution (October 2011). Available from, as of June 25, 2012: https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=147e033d-d997-4ef6-8bb5-a9ba372590b2


For more Drug Warnings (Complete) data for DROPERIDOL (26 total), please visit the HSDB record page.


4.4 Drug Indication

Droperidol is used to produce tranquilization and to reduce the incidence of nausea and vomiting in surgical and diagnostic procedures.


5 Pharmacology and Biochemistry
5.1 Pharmacology

Droperidol produces marked tranquilization and sedation. It allays apprehension and provides a state of mental detachment and indifference while maintaining a state of reflex alertness. Droperidol produces an antiemetic effect as evidenced by the antagonism of apomorphine in dogs. It lowers the incidence of nausea and vomiting during surgical procedures and provides antiemetic protection in the postoperative period. Droperidol potentiates other CNS depressants. It produces mild alpha-adrenergic blockade, peripheral vascular dilatation and reduction of the pressor effect of epinephrine. It can produce hypotension and decreased peripheral vascular resistance and may decrease pulmonary arterial pressure (particularly if it is abnormally high). It may reduce the incidence of epinephrine-induced arrhythmias, but it does not prevent other cardiac arrhythmias.


5.2 MeSH Pharmacological Classification

Adjuvants, Anesthesia

Agents that are administered in association with anesthetics to increase effectiveness, improve delivery, or decrease required dosage. (See all compounds classified as Adjuvants, Anesthesia.)


Antiemetics

Drugs used to prevent NAUSEA or VOMITING. (See all compounds classified as Antiemetics.)


Antipsychotic Agents

Agents that control agitated psychotic behavior, alleviate acute psychotic states, reduce psychotic symptoms, and exert a quieting effect. They are used in SCHIZOPHRENIA; senile dementia; transient psychosis following surgery; or MYOCARDIAL INFARCTION; etc. These drugs are often referred to as neuroleptics alluding to the tendency to produce neurological side effects, but not all antipsychotics are likely to produce such effects. Many of these drugs may also be effective against nausea, emesis, and pruritus. (See all compounds classified as Antipsychotic Agents.)


Dopamine D2 Receptor Antagonists

Compounds and drugs that bind to and inhibit or block the activation of DOPAMINE D2 RECEPTORS. (See all compounds classified as Dopamine D2 Receptor Antagonists.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
DROPERIDOL
5.3.2 FDA UNII
O9U0F09D5X
5.3.3 Pharmacological Classes
Dopamine-2 Receptor Antagonist [EPC]; Dopamine D2 Antagonists [MoA]
5.4 ATC Code

N05AD08

S76 | LUXPHARMA | Pharmaceuticals Marketed in Luxembourg | Pharmaceuticals marketed in Luxembourg, as published by d'Gesondheetskeess (CNS, la caisse nationale de sante, www.cns.lu), mapped by name to structures using CompTox by R. Singh et al. (in prep.). List downloaded from https://cns.public.lu/en/legislations/textes-coordonnes/liste-med-comm.html. Dataset DOI:10.5281/zenodo.4587355


N - Nervous system

N05 - Psycholeptics

N05A - Antipsychotics

N05AD - Butyrophenone derivatives

N05AD08 - Droperidol


5.5 Absorption, Distribution and Excretion

Absorption

Completely absorbed following intramuscular administration.


Following im or iv administration, the onset of pharmacologic action of droperidol occurs within 3-10 minutes, but peak pharmacologic effects may not be apparent until 30 minutes. The sedative and tranquilizing effects of droperidol generally persist for 2-4 hours following im or iv administration of a single dose; alteration of consciousness may persist for up to 12 hours.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


Droperidol reportedly crosses the blood-brain barrier and is distributed into the CSF.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


Droperidol drug reportedly crosses the placenta, but data are limited.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


It is not known if droperidol is distributed into milk.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


For more Absorption, Distribution and Excretion (Complete) data for DROPERIDOL (7 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Extensively metabolized.


Although the exact metabolic fate of droperidol is not clearly established, the drug is metabolized in the liver. The butyrophenone moiety of droperidol is metabolized to p-fluorophenylacetic acid, which is then conjugated with glycine. The nitrogenous moiety of droperidol appears to be metabolized to benzimidazolone and p-hydroxypiperidine.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


5.7 Biological Half-Life

Biphasic distribution. The rapid distribution phase is 1.4 ± 0.5 minutes and the slower distribution phase is 14.3 ± 6.5 minutes. Elimination half-life in adults is 134 ± 13 minutes and may be increased in geriatric patients. In children, it is 101.5 ± 26.4 minutes.


...Droperidol is rapidly absorbed after im injections, and plasma-level profiles of unchanged drug obey 2-compartment model kinetics. Plasma t1/2 is about 130 min...

The Chemical Society. Foreign Compound Metabolism in Mammals Volume 3. London: The Chemical Society, 1975., p. 122


5.8 Mechanism of Action

The exact mechanism of action is unknown, however, droperidol causes a CNS depression at subcortical levels of the brain, midbrain, and brainstem reticular formation. It may antagonize the actions of glutamic acid within the extrapyramidal system. It may also inhibit cathecolamine receptors and the reuptake of neurotransmiters and has strong central antidopaminergic action and weak central anticholinergic action. It can also produce ganglionic blockade and reduced affective response. The main actions seem to stem from its potent Dopamine(2) receptor antagonism with minor antagonistic effects on alpha-1 adrenergic receptors as well.


Within the CNS, droperidol acts principally at subcortical levels and exhibits a strong sedative effect. The drug also inhibits sympathetic postganglionic alpha-adrenergic receptor binding sites; however, therapeutic dosages of droperidol do not appear to completely block these receptors. Droperidol has antiemetic activity, but does not appear to exhibit analgesic activity.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


Because of its inhibitory effects on alpha-adrenergic receptor binding sites, droperidol attenuates the cardiovascular response to sympathomimetic amines. Droperidol also produces direct peripheral vasodilation, which alone or in conjunction with its alpha-adrenergic blocking activity may cause hypotension and decreased peripheral vascular resistance. Droperidol may decrease pulmonary arterial pressure (particularly in patients with preexisting elevations in pulmonary arterial pressure) and reduce the incidence of epinephrine-induced arrhythmias; however, droperidol's activity against other arrhythmias has not been observed.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 2648


Droperidol produces the inhibition of K+ channels in cardiac myocytes. However, the effects of droperidol on K+ channels have not been studied in blood vessels. Therefore, /investigators/ designed the present study to determine whether droperidol modulates the activity of adenosine triphosphate (ATP)-sensitive K+ channels in vascular smooth muscle cells. Rat aortic rings without endothelium were suspended or used for isometric force and membrane potential recordings, respectively. Vasorelaxation and hyperpolarization induced by levcromakalim (10(-8) to 10(-5) M or 10(-5) M, respectively) were completely abolished by the ATP-sensitive K+ channel antagonist glibenclamide (10(-5) M). Droperidol (10(-7) M) and an alpha-adrenergic receptor antagonist phentolamine (3 x 10(-9) M) caused a similar vasodilator effect (approximately 20% of vasorelaxation compared with maximal vasorelaxation induced by papaverine 3 x 10(-4) M, whereas glibenclamide did not alter vasorelaxation induced by droperidol. Droperidol (3 x 10(-8) M to 10(-7) M) augmented vasorelaxation and hyperpolarization produced by levcromakalim, whereas phentolamine (3 x 10(-9) M) did not alter this vasorelaxation. Glibenclamide (10(-5) M) abolished the vasodilating and hyperpolarizing effects of levcromakalim in the aorta treated with droperidol (10(-7) M). These results suggest that droperidol augments vasodilator activity via ATP-sensitive K+ channels. However, it is unlikely that this augmentation is mediated by the inhibition of alpha-adrenergic receptors in vascular smooth muscles.

PMID:16492829 Kinoshita H et al; Anesth Analg 102 (3): 786-91 (2006)


... An inhibitory dopaminergic receptor has been described that modulates catecholamine release from adrenal medulla. It has also been reported that low doses of droperidol increase arterial pressure in some patients with pheochromocytoma. The authors investigated whether an effect of droperidol on such a receptor could be one of the mechanisms involved in the hypertensive response. Isolated cat adrenal glands were perfused with Krebs-bicarbonate solution, and the catecholamine release was measured in the effluent. Then, the glands were stimulated by activation of the nicotinic receptor (nicotine, 5 uM), and the effect of low and high doses of droperidol and/or apomorphine on the catecholamine secretory responses evoked by nicotine was investigated. Low concentrations of droperidol (0.05 uM) (a dopaminergic antagonist) markedly increased the secretory response induced by nicotine whereas higher concentrations (50 uM) decreased it. Apomorphine (1 uM) (a dopaminergic agonist) inhibits the catecholamine release produced by nicotine, and this inhibitory effect was completely reversed by the lowest concentration of droperidol but not by the highest. In fact, the high concentration of droperidol further inhibited the catecholamine release induced by nicotine. The results suggest that the hypertensive responses evoked by low doses of droperidol in some patients with pheochromocytoma could be due to the inactivation of a dopaminergic inhibitory system present in the adrenal medulla that, under physiologic conditions, limits the amount of catecholamines released by the gland. Such as an inhibitory mechanism could operate in an exaggerated manner in patients with pheochromocytoma.

PMID:3777477 Montiel C et al; Anesthesiology 65 (5): 474-9 (1996)


For more Mechanism of Action (Complete) data for DROPERIDOL (6 total), please visit the HSDB record page.