Accession NumberDB01362
TypeSmall Molecule

Iohexol is an effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality. [PubChem]

External IDs Not Available
Product Ingredients Not Available
Approved Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
OmnipaqueInjection140 mg/mLIntravenousGe Healthcare2004-05-25Not applicableUs
OmnipaqueInjection, solution300 mg/mLIntravenousGe Healthcare1985-12-26Not applicableUs
OmnipaqueInjection180 mg/mLIntravenousGe Healthcare2004-07-15Not applicableUs
OmnipaqueInjection, solution350 mg/mLIntravenousGe Healthcare1985-12-26Not applicableUs
OmnipaqueInjection518 mg/mLIntrathecal; Intravascular; Intravenous; OralGe Healthcare1985-12-26Not applicableUs
Omnipaque 180Solution388 mgSubarachnoidGe Healthcare1998-03-08Not applicableCanada
Omnipaque 240Solution518 mgIntravascular; SubarachnoidGe Healthcare1998-05-26Not applicableCanada
Omnipaque 300Solution647 mgIntravascular; SubarachnoidGe Healthcare1998-03-05Not applicableCanada
Omnipaque 350Solution755 mgIntravascularGe Healthcare1998-03-05Not applicableCanada
OraltagFor solution4.5 g/1OralInterpharma Praha, a.s.2016-07-01Not applicableUs
Approved Generic Prescription ProductsNot Available
Approved Over the Counter ProductsNot Available
Unapproved/Other Products Not Available
International Brands
NycodenzNot Available
Brand mixturesNot Available
CAS number66108-95-0
WeightAverage: 821.1379
Monoisotopic: 820.880309705
Chemical FormulaC19H26I3N3O9

Iohexol ia used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures.

Structured Indications Not Available

Iohexol is an effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.

Mechanism of action

Organic iodine compounds block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. The degree of opacity produced by these compounds is directly proportional to the total amount (concentration and volume) of the iodinated contrast agent in the path of the x-rays. After intrathecal administration into the subarachnoid space, diffusion of iohexol in the CSF allows the visualization of the subarachnoid spaces of the head and spinal canal. After intravascular administration, iohexol makes opaque those vessels in its path of flow, allowing visualization of the internal structures until significant hemodilution occurs.

Related Articles

Small amounts are absorbed through the bladder via intravesical instillation. Following intrauterine instillation, the majority of the medium within the uterine cavity is discharged into the vagina immediately upon termination of procedure. However, any medium retained in the uterine or peritoneal cavity is absorbed systemically within 60 minutes. May not be absorbed for up to 24 hours if tubes are obstructed and dilated.

Volume of distribution
  • 350-849 mL/kg
Protein bindingNot Available
MetabolismNot Available
Route of elimination

Iohexol is absorbed from cerebrospinal fluid (CSF) into the bloodstream and is eliminated by renal excretion. No significant metabolism, deiodination, or biotransformation occurs.

Half life

Intrathecal half-life is 3.4 hours (mean). Intravascular is approximately 2 hours (with normal renal function).

  • 109 mL/min [Adult patients receiving 16-18 ml of iohexol (180 mgI/mL) by lumbar intrathecal injection]

Non-ionic radiocontrast agents like iohexol are cytotoxic to renal cells. The toxic effects include apoptosis, cellular energy failure, disruption of calcium homeostasis, and disturbance of tubular cell polarity, and are thought to be linked to oxidative stress.

Affected organisms
  • Humans and other mammals
PathwaysNot Available
Pharmacogenomic Effects/ADRs Not Available
Drug Interactions
DrugInteractionDrug group
AldesleukinThe risk of a hypersensitivity reaction to Iohexol is increased when it is combined with Aldesleukin.Approved
MetforminThe risk or severity of adverse effects can be increased when Iohexol is combined with Metformin.Approved
Food InteractionsNot Available
Synthesis Reference

Xiu C. Wang, Steve A. Chamberlin, Ashok V. Bhatia, Gregg E. Robinson, John Hufnagel, "Process for the preparation of iohexol." U.S. Patent US5705692, issued December, 1985.

General References
  1. Kawada TK: Iohexol and iopamidol: second-generation nonionic radiographic contrast media. Drug Intell Clin Pharm. 1985 Jul-Aug;19(7-8):525-9. [PubMed:3896713 ]
  2. Shaw DD, Potts DG: Toxicology of iohexol. Invest Radiol. 1985 Jan-Feb;20(1 Suppl):S10-3. [PubMed:3882609 ]
External Links
ATC CodesV08AB02 — Iohexol
AHFS Codes
  • 36:68.00
PDB EntriesNot Available
FDA labelNot Available
MSDSNot Available
Clinical Trials
Clinical Trials
1CompletedBasic ScienceHealthy Volunteers1
1CompletedTreatmentInfections, Human Immunodeficiency Virus and Tuberculosis1
2RecruitingBasic ScienceAcute Kidney Injury (AKI)1
3CompletedDiagnosticAcute Circulatory Failure1
3CompletedTreatmentIschaemic Heart Diseases1
3RecruitingDiagnosticAcute Renal Failure (ARF)1
3RecruitingDiagnosticKnown or Suspected Abdominal Disease1
4CompletedNot AvailableHIV Disease1
4CompletedDiagnosticHealthy Volunteers1
4CompletedTreatmentHIV-1 Infections1
Not AvailableActive Not RecruitingDiagnosticAll1
Not AvailableActive Not RecruitingDiagnosticLung Cancer Non-Small Cell Cancer (NSCLC) / Lung Cancer Small Cell Lung Cancer (SCLC) / Lung Cancers / Mesothelioma1
Not AvailableCompletedNot AvailableAging / HIV Disease1
Not AvailableCompletedNot AvailableImpaired Renal Function / Renal Diseases1
Not AvailableNot Yet RecruitingTreatmentIntestinal Obstruction1
Not AvailableRecruitingOtherAortic and Arterial Anomalies / Aortic Aneurysms / Contrast Induced Nephropathy (CIN)1
Not AvailableTerminatedNot AvailableMalignant Neoplasm of Pancreas1
Not AvailableTerminatedBasic ScienceFabry's Disease1
ManufacturersNot Available
Dosage forms
InjectionIntrathecal; Intravascular; Intravenous; Oral518 mg/mL
InjectionIntravenous140 mg/mL
InjectionIntravenous180 mg/mL
Injection, solutionIntravenous300 mg/mL
Injection, solutionIntravenous350 mg/mL
SolutionSubarachnoid388 mg
SolutionIntravascular; Subarachnoid518 mg
SolutionIntravascular; Subarachnoid647 mg
SolutionIntravascular755 mg
For solutionOral4.5 g/1
Unit descriptionCostUnit
Myelo-kit 180 mg/ml62.19USD each
Omnipaque 240 mg/ml vial5.34USD ml
Omnipaque 180 mg/ml vial4.92USD ml
Omnipaque 300 mg/ml vial4.82USD ml
Omnipaque 210 mg/ml vial3.53USD ml
Omnipaque 350 mg/ml cartridge2.29USD ml
Omnipaque 300 mg/ml cartridge2.17USD ml
Omnipaque 240 mg/ml cartridge1.77USD ml
Omnipaque 300 mg/ml syringe1.08USD ml
Omnipaque 350 mg/ml infu btl1.08USD ml
Omnipaque 140 mg/ml vial0.78USD ml
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
PatentsNot Available
Experimental Properties
melting point (°C)174-180 °CPhysProp
logP-3.05HANSCH,C & LEO,AJ (1985)
Predicted Properties
Water Solubility0.796 mg/mLALOGPS
pKa (Strongest Acidic)11.73ChemAxon
pKa (Strongest Basic)-3ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count9ChemAxon
Hydrogen Donor Count8ChemAxon
Polar Surface Area199.89 Å2ChemAxon
Rotatable Bond Count12ChemAxon
Refractivity148.84 m3·mol-1ChemAxon
Polarizability60.37 Å3ChemAxon
Number of Rings1ChemAxon
Rule of FiveNoChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
Human Intestinal Absorption-0.8406
Blood Brain Barrier-0.5082
Caco-2 permeable-0.6474
P-glycoprotein substrateSubstrate0.5
P-glycoprotein inhibitor INon-inhibitor0.8375
P-glycoprotein inhibitor IINon-inhibitor0.8629
Renal organic cation transporterNon-inhibitor0.9534
CYP450 2C9 substrateNon-substrate0.7747
CYP450 2D6 substrateNon-substrate0.8175
CYP450 3A4 substrateNon-substrate0.6895
CYP450 1A2 substrateNon-inhibitor0.919
CYP450 2C9 inhibitorNon-inhibitor0.9071
CYP450 2D6 inhibitorNon-inhibitor0.9303
CYP450 2C19 inhibitorNon-inhibitor0.9025
CYP450 3A4 inhibitorNon-inhibitor0.971
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.7514
Ames testNon AMES toxic0.9035
BiodegradationNot ready biodegradable0.9937
Rat acute toxicity1.6446 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9895
hERG inhibition (predictor II)Non-inhibitor0.7193
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397 )
Mass Spec (NIST)Not Available
Spectrum TypeDescriptionSplash Key
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0udi-0000000090-ec4e884f5d1e3e37a84fView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0udi-0020002090-d8ff0c2813768e3cf012View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-00dj-0009850000-7a1ca449a56d19c39ea8View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0fk9-0009120000-a8c863a64d387cfd461aView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0kmi-0496000000-bff588cc0e98918355e8View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-05fu-0492000000-4a9469f17183d2f9f291View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0udi-0020003090-7423fd2df7e59f0f78eeView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0fka-0008951000-ea0d52cf6d356a7f3590View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0fk9-0029120000-e5ff4d33e064ff47ff49View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0kmi-0395000000-775d49075e4ad66be119View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-05i1-0492000000-1a8b12a2e372f5b00ca1View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , positivesplash10-0udi-0000000090-262fc3f19d8442742408View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, NegativeNot Available
DescriptionThis compound belongs to the class of chemical entities known as o-haloacetanilides. These are organic compounds containing an acetamide group conjugated to a phenyl group, which is in turn ortho-substituted with a halogen atom.
KingdomChemical entities
Super ClassOrganic compounds
Sub ClassBenzene and substituted derivatives
Direct ParentO-haloacetanilides
Alternative ParentsP-haloacetanilides / Iodobenzenes / Aryl iodides / Tertiary carboxylic acid amides / Acetamides / Secondary alcohols / Propargyl-type 1,3-dipolar organic compounds / Carboximidic acids / Primary alcohols / Organopnictogen compounds
SubstituentsO-haloacetanilide / P-haloacetanilide / Halobenzene / Iodobenzene / Aryl halide / Aryl iodide / Acetamide / Tertiary carboxylic acid amide / Carboxamide group / Secondary alcohol
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptorsorganoiodine compound, benzenedicarboxamide (CHEBI:31709 )
Drug created on July 06, 2007 13:54 / Updated on July 18, 2017 16:58