Please Wait
Applying Filters...
Menu
$ API Ref.Price (USD/KG) : 90Xls
2D Structure
Also known as: Ketoconazole, (+)-ketoconazole, 65277-42-1, (2r,4s)-ketoconazole, 142128-59-4, Kuric
Molecular Formula
C26H28Cl2N4O4
Molecular Weight
531.4  g/mol
InChI Key
XMAYWYJOQHXEEK-OZXSUGGESA-N

Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
1-[4-[4-[[(2R,4S)-2-(2,4-dichlorophenyl)-2-(imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazin-1-yl]ethanone
2.1.2 InChI
InChI=1S/C26H28Cl2N4O4/c1-19(33)31-10-12-32(13-11-31)21-3-5-22(6-4-21)34-15-23-16-35-26(36-23,17-30-9-8-29-18-30)24-7-2-20(27)14-25(24)28/h2-9,14,18,23H,10-13,15-17H2,1H3/t23-,26-/m0/s1
2.1.3 InChI Key
XMAYWYJOQHXEEK-OZXSUGGESA-N
2.1.4 Canonical SMILES
CC(=O)N1CCN(CC1)C2=CC=C(C=C2)OCC3COC(O3)(CN4C=CN=C4)C5=C(C=C(C=C5)Cl)Cl
2.1.5 Isomeric SMILES
CC(=O)N1CCN(CC1)C2=CC=C(C=C2)OC[C@H]3CO[C@](O3)(CN4C=CN=C4)C5=C(C=C(C=C5)Cl)Cl
2.2 Synonyms
2.2.1 MeSH Synonyms

1. Ketoconazole

2. Nizoral

3. R 41400

4. R-41400

5. R41,400

6. R41400

2.2.2 Depositor-Supplied Synonyms

1. Ketoconazole

2. (+)-ketoconazole

3. 65277-42-1

4. (2r,4s)-ketoconazole

5. 142128-59-4

6. Kuric

7. Ketocanazole

8. Cpd000058460

9. Chembl75

10. Smr000058460

11. Mls000069784

12. Mls001146934

13. 1-[4-[4-[[(2r,4s)-2-(2,4-dichlorophenyl)-2-(imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazin-1-yl]ethanone

14. 1-acetyl-4-(4-{[(2r,4s)-2-(2,4-dichlorophenyl)-2-(1h-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy}phenyl)piperazine

15. Chebi:48336

16. Dsstox_cid_9879

17. R-41400

18. Dsstox_rid_78829

19. Dsstox_gsid_29879

20. 1-(4-(4-(((2r,4s)-2-((1h-imidazol-1-yl)methyl)-2-(2,4-dichlorophenyl)-1,3-dioxolan-4-yl)methoxy)phenyl)piperazin-1-yl)ethanone

21. Mfcd00058579

22. Rac-trans-ketoconazole

23. Ktz

24. Sr-01000075626

25. Sr-01000597381

26. Ketoconazole (k)

27. (+)-ketoconazol

28. Ketoconazole,(s)

29. Ncgc00016907-01

30. Prestwick_744

31. Cas-65277-42-1

32. Tocris-1103

33. Opera_id_397

34. Prestwick0_000389

35. Prestwick1_000389

36. Prestwick2_000389

37. Prestwick3_000389

38. R 41,400

39. Upcmld-dp138

40. Schembl8407

41. Lopac0_000666

42. Bspbio_000577

43. Mls000758224

44. Mls001423987

45. Mls002207053

46. Mls002222255

47. Bidd:gt0696

48. Us9150527, Ketoconazole

49. Spbio_002498

50. Amy917

51. Bdbm8610

52. Bpbio1_000635

53. Dtxsid7029879

54. Upcmld-dp138:001

55. Bdbm60666

56. Hy-b0105a

57. Ketoconazole, >=98% (hplc)

58. Dtxsid901316748

59. Hms1569m19

60. Hms2051a19

61. Hms2089n05

62. Hms2096m19

63. Hms2234h17

64. Hms3262e13

65. Hms3414j19

66. Hms3678j17

67. Hms3713m19

68. Zinc643138

69. Bcp28528

70. Piperazine, (+/-)-1-acetyl-4-[4-[[(2r,4s)-2-(2,4-dichlorophenyl)-2-(1h-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-, Rel-

71. Ketoconazole 2.0 Mg/ml In Methanol

72. Tox21_110676

73. Tox21_300267

74. Tox21_500666

75. Ei-107

76. S1353

77. Akos007930650

78. Ccg-100815

79. Cs-1846

80. Ks-1205

81. Lp00666

82. Nc00065

83. Sdccgsbi-0050645.p002

84. Ketoconazole 100 Microg/ml In Methanol

85. Mrf-0000100

86. 24f2-1,25(oh)d3

87. Ncgc00025000-01

88. Ncgc00025000-02

89. Ncgc00025000-03

90. Ncgc00025000-04

91. Ncgc00025000-05

92. Ncgc00025000-06

93. Ncgc00025000-07

94. Ncgc00025000-08

95. Ncgc00025000-09

96. Ncgc00025000-10

97. Ncgc00025000-14

98. Ncgc00025000-16

99. Ncgc00025000-28

100. Ncgc00253967-01

101. Ncgc00261351-01

102. ( Inverted Exclamation Marka)-ketoconazol

103. (+/-)-cis-1-acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2-(imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazine

104. Ac-15957

105. Cis-1-acetyl-4-[4-[[2-(2,4-

106. 3-dioxolan-4-yl)-methoxy]phenyl)piperazine

107. Ketoconazole 100 Microg/ml In Acetonitrile

108. Eu-0100666

109. K0045

110. Sw196888-4

111. Bim-0050645.0001

112. K 1003

113. M02048

114. 277k421

115. Ketoconazole, Antibiotic For Culture Media Use Only

116. Q-201267

117. Sr-01000075626-1

118. Sr-01000075626-4

119. Sr-01000597381-1

120. Sr-01000597381-6

121. Brd-k29113274-001-03-6

122. Brd-k29113274-001-11-9

123. Brd-k29113274-001-21-8

124. Q27121163

125. (+)-r 41400

126. Ketoconazole, British Pharmacopoeia (bp) Reference Standard

127. Ketoconazole, European Pharmacopoeia (ep) Reference Standard

128. Ketoconazole, United States Pharmacopeia (usp) Reference Standard

129. Dichlorophenyl)-2-(1h-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-piperazine

130. Ketoconazole, Pharmaceutical Secondary Standard; Certified Reference Material

131. (2r,4s)-1-acetyl-4-(4-{[2-(2,4-dichlorophenyl)-2-(1h-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy}phenyl)piperazine

132. 1-(4-(4-(((2r,4s)-2-((1h-imidazol-1-yl)methyl)-2-(2,4-dichlorophenyl)-1,3-dioxolan-4-yl)methoxy)phenyl)piperazin-1-yl)ethan-1-one

133. Cis-1-acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2-(1h-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl] Methoxy]phenyl]piperazine

134. Kz

135. Piperazine, (+)-1-acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2-(1h-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-

2.3 Create Date
2005-08-01
3 Chemical and Physical Properties
Molecular Weight 531.4 g/mol
Molecular Formula C26H28Cl2N4O4
XLogP34.3
Hydrogen Bond Donor Count0
Hydrogen Bond Acceptor Count6
Rotatable Bond Count7
Exact Mass530.1487608 g/mol
Monoisotopic Mass530.1487608 g/mol
Topological Polar Surface Area69.1 Ų
Heavy Atom Count36
Formal Charge0
Complexity735
Isotope Atom Count0
Defined Atom Stereocenter Count2
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 10  
Drug NameExtina
PubMed HealthKetoconazole
Drug LabelEXTINA Foam contains 2% ketoconazole USP, an antifungal agent, in a thermolabile hydroethanolic foam for topical application.The chemical name for ketoconazole is piperazine, 1-acetyl-4-[4-[[2-(2,4-dichlorophenyl) -2-(1H-imidazol-l-ylmethyl)-1,3-di...
Active IngredientKetoconazole
Dosage FormAerosol, foam
RouteTopical
Strength2%
Market StatusPrescription
CompanyDelcor Abet

2 of 10  
Drug NameKetoconazole
PubMed HealthKetoconazole
Drug LabelNIZORAL is a synthetic broad-spectrum antifungal agent available in scored white tablets, each containing 200 mg ketoconazole base for oral administration. Inactive ingredients are colloidal silicon dioxide, corn starch, lactose, magnesium stearate...
Active IngredientKetoconazole
Dosage FormShampoo; Tablet; Cream; Aerosol, foam
RouteOral; Topical
Strength200mg; 2%
Market StatusPrescription
CompanyTeva; Taro; Fougera Pharms; Perrigo New York; Tolmar; Mylan; Perrigo Israel

3 of 10  
Drug NameNizoral
PubMed HealthKetoconazole
Drug LabelNIZORAL is a synthetic broad-spectrum antifungal agent available in scored white tablets, each containing 200 mg ketoconazole base for oral administration. Inactive ingredients are colloidal silicon dioxide, corn starch, lactose, magnesium stearate...
Active IngredientKetoconazole
Dosage FormShampoo
RouteTopical
Strength2%
Market StatusPrescription
CompanyJanben Pharms

4 of 10  
Drug NameNizoral a-d
PubMed HealthKetoconazole (On the skin)
Active IngredientKetoconazole
Dosage FormShampoo
RouteTopical
Strength1%
Market StatusOver the Counter
CompanyMcneil Cons

5 of 10  
Drug NameXolegel
PubMed HealthKetoconazole
Drug LabelXOLEGEL contains the antifungal agent ketoconazole USP at 2% in a topical anhydrous gel vehicle for topical administration.Chemically, ketoconazole is ()-cis-1-Acetyl-4-[p-[[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methox...
Active IngredientKetoconazole
Dosage FormGel
RouteTopical
Strength2%
Market StatusPrescription
CompanyAqua Pharms

6 of 10  
Drug NameExtina
PubMed HealthKetoconazole
Drug LabelEXTINA Foam contains 2% ketoconazole USP, an antifungal agent, in a thermolabile hydroethanolic foam for topical application.The chemical name for ketoconazole is piperazine, 1-acetyl-4-[4-[[2-(2,4-dichlorophenyl) -2-(1H-imidazol-l-ylmethyl)-1,3-di...
Active IngredientKetoconazole
Dosage FormAerosol, foam
RouteTopical
Strength2%
Market StatusPrescription
CompanyDelcor Abet

7 of 10  
Drug NameKetoconazole
PubMed HealthKetoconazole
Drug LabelNIZORAL is a synthetic broad-spectrum antifungal agent available in scored white tablets, each containing 200 mg ketoconazole base for oral administration. Inactive ingredients are colloidal silicon dioxide, corn starch, lactose, magnesium stearate...
Active IngredientKetoconazole
Dosage FormShampoo; Tablet; Cream; Aerosol, foam
RouteOral; Topical
Strength200mg; 2%
Market StatusPrescription
CompanyTeva; Taro; Fougera Pharms; Perrigo New York; Tolmar; Mylan; Perrigo Israel

8 of 10  
Drug NameNizoral
PubMed HealthKetoconazole
Drug LabelNIZORAL is a synthetic broad-spectrum antifungal agent available in scored white tablets, each containing 200 mg ketoconazole base for oral administration. Inactive ingredients are colloidal silicon dioxide, corn starch, lactose, magnesium stearate...
Active IngredientKetoconazole
Dosage FormShampoo
RouteTopical
Strength2%
Market StatusPrescription
CompanyJanben Pharms

9 of 10  
Drug NameNizoral a-d
PubMed HealthKetoconazole (On the skin)
Active IngredientKetoconazole
Dosage FormShampoo
RouteTopical
Strength1%
Market StatusOver the Counter
CompanyMcneil Cons

10 of 10  
Drug NameXolegel
PubMed HealthKetoconazole
Drug LabelXOLEGEL contains the antifungal agent ketoconazole USP at 2% in a topical anhydrous gel vehicle for topical administration.Chemically, ketoconazole is ()-cis-1-Acetyl-4-[p-[[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methox...
Active IngredientKetoconazole
Dosage FormGel
RouteTopical
Strength2%
Market StatusPrescription
CompanyAqua Pharms

4.2 Therapeutic Uses

Antifungal agents

National Library of Medicine's Medical Subject Headings. Ketoconazole. Online file (MeSH, 2014). Available from, as of August 28, 2014: https://www.nlm.nih.gov/mesh/2014/mesh_browser/MBrowser.html


Nizoral Tablets should be used only when other effective antifungal therapy is not available or tolerated and the potential benefits are considered to outweigh the potential risks. Nizoral (ketoconazole) Tablets are indicated for the treatment of the following systemic fungal infections in patients who have failed or who are intolerant to other therapies: blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, and paracoccidioidomycosis. Nizoral Tablets should not be used for fungal meningitis because it penetrates poorly into the cerebrospinal fluid. /Included in US product label/

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


Oral ketoconazole has been used for the palliative treatment of Cushing's syndrome (hypercortisolism), including adrenocortical hyperfunction associated with adrenal or pituitary adenoma or ectopic corticotropin-secreting tumors. Based on ketoconazole's endocrine effects, the drug has been used in the treatment of advanced prostatic carcinoma. Safety and efficacy of ketoconazole have not been established for either of these indications. Oral ketoconazole also has been used in the treatment of hypercalcemia in patients with sarcoidosis and the treatment of tuberculosis-associated hypercalcemia and idiopathic infantile hypercalcemia and hypercalciuria. /NOT included in US product label/

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


Ketoconazole has been used for the treatment of sporotrichosis caused by Sporothrix schenckii; however, the drug is not recommended since it is less effective and associated with more adverse effects than some other azoles. Oral itraconazole is considered the drug of choice for the treatment of cutaneous, lymphocutaneous, or mild pulmonary or osteoarticular sporotrichosis and for follow-up therapy in more severe infections after a response has been obtained with IV amphotericin B. /NOT included in US product label/

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


For more Therapeutic Uses (Complete) data for KETOCONAZOLE (18 total), please visit the HSDB record page.


4.3 Drug Warning

/BOXED WARNING/ WARNING. Nizoral Tablets should be used only when other effective antifungal therapy is not available or tolerated and the potential benefits are considered to outweigh the potential risks. Hepatotoxicity: Serious hepatotoxicity, including cases with a fatal outcome or requiring liver transplantation has occurred with the use of oral ketoconazole. Some patients had no obvious risk factors for liver disease. Patients receiving this drug should be informed by the physician of the risk and should be closely monitored. QT Prolongation and Drug Interactions Leading to QT Prolongation: Co-administration of the following drugs with ketoconazole is contraindicated: dofetilide, quinidine, pimozide, cisapride, methadone, disopyramide, dronedarone, ranolazine. Ketoconazole can cause elevated plasma concentrations of these drugs and may prolong QT intervals, sometimes resulting in life-threatening ventricular dysrhythmias such as torsades de pointes.

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


Transient increases in serum AST, ALT, and alkaline phosphatase concentrations may occur during ketoconazole therapy. Serious hepatotoxicity has occurred in patients receiving oral ketoconazole, including cases that were fatal or required liver transplantation. Hepatotoxicity may be hepatocellular (in most cases), cholestatic, or a mixed pattern of injury. Although ketoconazole-induced hepatotoxicity usually is reversible following discontinuance of the drug, recovery may take several months and rarely death has occurred. Symptomatic hepatotoxicity usually is apparent within the first few months of ketoconazole therapy, but occasionally may be apparent within the first week of therapy. Some patients with ketoconazole-induced hepatotoxicity had no obvious risk factors for liver disease. Serious hepatotoxicity has been reported in patients receiving high oral ketoconazole dosage for short treatment durations and in patients receiving low oral dosage of the drug for long durations. Many of the reported cases of hepatotoxicity occurred in patients who received the drug for the treatment of tinea unguium (onychomycosi or the treatment of chronic, refractory dermatophytoses. Ketoconazole-induced hepatitis has been reported in some children.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014, p. 521


Coadministration of a number of CYP3A4 substrates such as dofetilide, quinidine cisapride and pimozide is contraindicated with Nizoral Tablets. Coadministration with ketoconazole can cause elevated plasma concentrations of these drugs and may increase or prolong both therapeutic and adverse effects to such an extent that a potentially serious adverse reaction may occur. For example, increased plasma concentrations of some of these drugs can lead to QT prolongation and sometimes resulting in life-threatening ventricular tachyarrhythmias including occurrences of torsades de pointes, a potentially fatal arrhythmia. Additionally, the following other drugs are contraindicated with Nizoral Tablets: methadone, disopyramide, dronedarone, ergot alkaloids such as dihydroergotamine, ergometrine, ergotamine, methylergometrine, irinotecan, lurasidone, oral midazolam, alprazolam, triazolam, felodipine, nisoldipine, ranolazine, tolvaptan, eplerenone, lovastatin, simvastatin and colchicine.

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


The use of Nizoral Tablets is contraindicated in patients with acute or chronic liver disease.

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


For more Drug Warnings (Complete) data for KETOCONAZOLE (46 total), please visit the HSDB record page.


4.4 Drug Indication

Ketoconazole HRA is indicated for the treatment of endogenous Cushings syndrome in adults and adolescents above the age of 12 years.


5 Pharmacology and Biochemistry
5.1 MeSH Pharmacological Classification

Cytochrome P-450 CYP3A Inhibitors

Drugs and compounds which inhibit or antagonize the biosynthesis or actions of CYTOCHROME P-450 CYP3A. (See all compounds classified as Cytochrome P-450 CYP3A Inhibitors.)


14-alpha Demethylase Inhibitors

Compounds that specifically inhibit STEROL 14-DEMETHYLASE. A variety of azole-derived ANTIFUNGAL AGENTS act through this mechanism. (See all compounds classified as 14-alpha Demethylase Inhibitors.)


Antifungal Agents

Substances that destroy fungi by suppressing their ability to grow or reproduce. They differ from FUNGICIDES, INDUSTRIAL because they defend against fungi present in human or animal tissues. (See all compounds classified as Antifungal Agents.)


5.2 FDA Pharmacological Classification
5.2.1 Pharmacological Classes
Azoles [CS]; Cytochrome P450 3A4 Inhibitors [MoA]; Cytochrome P450 3A5 Inhibitors [MoA]; P-Glycoprotein Inhibitors [MoA]; Azole Antifungal [EPC]
5.3 ATC Code

J02AB02


D01AC08

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


D - Dermatologicals

D01 - Antifungals for dermatological use

D01A - Antifungals for topical use

D01AC - Imidazole and triazole derivatives

D01AC08 - Ketoconazole


G - Genito urinary system and sex hormones

G01 - Gynecological antiinfectives and antiseptics

G01A - Antiinfectives and antiseptics, excl. combinations with corticosteroids

G01AF - Imidazole derivatives

G01AF11 - Ketoconazole


H - Systemic hormonal preparations, excl. sex hormones and insulins

H02 - Corticosteroids for systemic use

H02C - Antiadrenal preparations

H02CA - Anticorticosteroids

H02CA03 - Ketoconazole


J - Antiinfectives for systemic use

J02 - Antimycotics for systemic use

J02A - Antimycotics for systemic use

J02AB - Imidazole derivatives

J02AB02 - Ketoconazole


5.4 Absorption, Distribution and Excretion

Ketoconazole is rapidly absorbed from the GI tract. Following oral administration, ketoconazole is dissolved in gastric secretions and converted to the hydrochloride salt prior to absorption from the stomach.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


The effect of food on the rate and extent of GI absorption of ketoconazole has not been clearly determined. Some clinicians have reported that administration of ketoconazole to fasting individuals results in higher plasma concentrations of the drug than does administration with food. However, the manufacturer states that administration of ketoconazole with food increases the extent of absorption and results in more consistent plasma concentrations of the drug. The manufacturer suggests that food increases absorption of ketoconazole by increasing the rate and/or extent of dissolution of ketoconazole (e.g., by increasing bile secretions) or by delaying stomach emptying.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


Ketoconazole is a weak dibasic agent and thus requires acidity for dissolution and absorption.

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


The bioavailability of oral ketoconazole depends on the pH of the gastric contents in the stomach; an increase in the pH results in decreased absorption of the drug. Decreased bioavailability of ketoconazole has been reported in patients with acquired immunodeficiency syndrome (AIDS), probably because of gastric hypochlorhydria associated with this condition; concomitant administration of dilute hydrochloric acid solution normalized absorption of the drug in these patients.198 Concomitant administration of an acidic beverage may increase bioavailability of oral ketoconazole in some individuals with achlorhydria.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


For more Absorption, Distribution and Excretion (Complete) data for KETOCONAZOLE (19 total), please visit the HSDB record page.


5.5 Metabolism/Metabolites

Ketoconazole is partially metabolized, in the liver, to several inactive metabolites by oxidation and degradation of the imidazole and piperazine rings, by oxidative O-dealkylation, and by aromatic hydroxylation.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


5.6 Biological Half-Life

Plasma concentrations of ketoconazole appear to decline in a biphasic manner with a half-life of approximately 2 hours in the initial phase and approximately 8 hours in the terminal phase.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014


Elimination from plasma is biphasic with a half-life of 2 hours during the first 10 hours and 8 hours thereafter.

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


5.7 Mechanism of Action

Ketoconazole blocks the synthesis of ergosterol, a key component of the fungal cell membrane, through the inhibition of cytochrome P-450 dependent enzyme lanosterol 14alpha-demethylase responsible for the conversion of lanosterol to ergosterol in the fungal cell membrane. This results in an accumulation of methylated sterol precursors and a depletion of ergosterol within the cell membrane thus weakening the structure and function of the fungal cell membrane.

NIH; DailyMed. Current Medication Information for Nizoral (Ketoconazole) Tablet (Revised: March 2014). Available from, as of November 11, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=090660c1-6e6d-457f-adb5-046ddfcd1465


Like other azole antifungal agents, ketoconazole presumably exerts its antifungal activity by altering cellular membranes, resulting in increased membrane permeability, secondary metabolic effects, and growth inhibition. Although the exact mechanism of action of ketoconazole has not been fully determined, it has been suggested that the fungistatic activity of the drug may result from interference with ergosterol synthesis, probably via inhibition of C-14 demethylation of sterol intermediates (e.g., lanosterol). The fungicidal activity of ketoconazole at high concentrations may result from a direct physiochemical effect of the drug on the fungal cell membrane.

American Society of Health-System Pharmacists 2014; Drug Information 2014. Bethesda, MD. 2014