Iohexol

The iodine atoms in iohexol provide attenuation of X-rays in direct proportion to the concentration of iohexol. Since concentration changes over time, iohexol provides time-dependent image contrast which may assist in visualizing body structures.

• OMNIPAQUE is a radiographic contrast agent indicated for intrathecal, intra-arterial, intravenous, oral, rectal, intraarticular, and body cavity imaging procedures in adults and pediatric patients. ( 1 ) 1.1 Intrathecal Procedures ‡ OMNIPAQUE is indicated for: Myelography and computerized tomography (CT) myelography (lumbar, thoracic, cervical, total columnar) in adults and pediatric patients aged 2 weeks and older CT cisternography in adults and pediatric patients aged 2 weeks and older 1.2 Intra-arterial Procedures ‡ OMNIPAQUE is indicated for: Cardiac ventriculography in adults and pediatric patients Aortography including studies of aorta and its branches in adults and pediatric patients Selective coronary arteriography in adults Cerebral arteriography in adults Peripheral arteriography in adults Intra-arterial digital subtraction angiography (IA-DSA) of the head, neck, abdominal, renal, and peripheral vessels in adults Pulmonary angiography in pediatric patients 1.3 Intravenous Procedures ‡ OMNIPAQUE is indicated for: Excretory urography in adults and pediatric patients CT of the head and body in adults and pediatric patients Peripheral venography (phlebography) in adults Intra…

• OMNIPAQUE for hysterosalpingography is contraindicated during pregnancy or suspected pregnancy, menstruation or when menstruation is imminent, within 6 months after termination of pregnancy, within 30 days after conization or curettage, when signs of infection are present in any portion of the genital tract including the external genitalia, and when reproductive tract neoplasia is known or suspected because of the risk of peritoneal spread of neoplasm. Hysterosalpingography during pregnancy (or suspected pregnancy), menstruation (or when menstruation is imminent), within 6 months after termination of pregnancy, within 30 days after conization or curettage, when signs of infection are present in any portion of the genital tract, including the external genitalia, and when reproductive tract neoplasia is known or suspected.contraindicated

For each imaging procedure, specific dosage forms, concentrations, and presentations are recommended. Individualize the concentration and volume according to the specific dosing tables and accounting for factors such as age, body weight, and condition of the patient, and the equipment and imaging technique used. ( 2.2 , 2.3 , 2.4 , 2.5 , 2.6 , 2.7 , 2.8 , 2.9 ) See full prescribing information for complete dosing and administration information. ( 2 ) 2.1 Important Dosage and Administration Instructions Specific dosage forms, concentrations, and presentations of OMNIPAQUE are recommended for each type of imaging procedure [see Dosage and Administration (2.2 , 2.3 , 2.4 , 2.5 , 2.6 , 2.7 , 2.8 , 2.9) and Warnings and Precautions (5.1 , 5.2) ]. Individualize the volume, strength, and rate of administration of OMNIPAQUE injection according to the specific dosing tables [see Dosage and Administration (2.2 , 2.3 , 2.4 , 2.5 , 2.6 , 2.7 , 2.8 , 2.9) ] . Consider factors such as age, body weight, vessel size, blood flow rate within the vessel, anticipated pathology, degree and extent of opacification required, structures or area to be examined, disease processes affecting the patient, and equipment and technique to be employed. Hydrate patients before and after administration of OMNIPAQUE injection [see Warnings and Precautions (5.4) ]. Use aseptic technique for all handling and administration of OMNIPAQUE injection. Administer OMNIPAQUE injection at either body (37°C, 98.6°F) or room temperature (20°C to 25°C, 68°F to 77°F).

Hypersensitivity Reactions: Life-threatening or fatal reactions can occur. Always have emergency equipment and trained personnel available. ( 5.3 ) Acute Kidney Injury: Acute injury including renal failure can occur. Minimize dose and maintain adequate hydration to minimize risk. ( 5.4 ) Cardiovascular Adverse Reactions: Hemodynamic disturbances including shock and cardiac arrest may occur during or after administration. ( 5.5 ) Thyroid Dysfunction in Pediatric Patients 0 to 3 Years of Age: Individualize thyroid function monitoring based on risk factors such as prematurity. ( 5.9 ) 5.1 Risks Associated with Intrathecal Administration of OMNIPAQUE Injection 140 mg Iodine/mL and 350 mg Iodine/mL Use only the iodine concentrations and presentations recommended for intrathecal procedures [see Dosage and Administration (2.2 , 2.8) ]. Intrathecal administration of OMNIPAQUE of a wrong iodine concentration, even if inadvertent, can cause death, convulsions, seizures, cerebral hemorrhage, coma, paralysis, arachnoiditis, acute renal failure, cardiac arrest, rhabdomyolysis, hyperthermia, and brain edema. 5.2 Risks Associated with Parenteral Administration of OMNIPAQUE Oral Solution Adverse reactions such as hemolysis may occur if OMNIPAQUE oral solution is administered intravenously or intraarterially due to low osmolality [see Description (11) ] . OMNIPAQUE oral solution is for oral use only. 5.3 Hypersensitivity Reactions OMNIPAQUE can cause life-threatening or fatal hypersensitivity reactions including anaphylaxis.

The following clinically significant adverse reactions are described elsewhere in the labeling: Risks Associated with Intrathecal Administration of OMNIPAQUE Injection 140 mg Iodine/mL and 350 mg Iodine/mL [see Warnings and Precautions (5.1) ] Risks Associated with Parenteral Administration of OMNIPAQUE Oral Solution [see Warnings and Precautions (5.2) ] Hypersensitivity Reactions [see Warnings and Precautions (5.3) ] Acute Kidney Injury [see Warnings and Precautions (5.4) ] Cardiovascular Adverse Reactions [see Warnings and Precautions (5.5) ] Thromboembolic Events [ see Warnings and Precautions (5.6) ] Thyroid Dysfunction in Pediatric Patients 0 to 3 Years of Age [see Warnings and Precautions (5.9) ] Severe Cutaneous Adverse Reactions [see Warnings and Precautions (5.12) ] Most common adverse reactions (incidence ≥ 1%) in adult patients Intrathecal: Headaches, pain including backache, neckache, stiffness and neuralgia, nausea, vomiting, dizziness Intra-arterial or intravenous: Pain, vision abnormalities (including blurred vision and photomas), headache, taste perversion, arrhythmias including premature ventricular contractions (PVCs) and premature atrial contractions (PACs), angina/chest pain, nausea Oral: Diarrhea, nausea, vomiting, abdominal pain, flatulence, headache Body Cavity: Pain, swelling, heat sensation ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact GE Healthcare at 1-800-654-0118 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Lactation: A lactating woman may pump and discard breast milk for 10 hours after OMNIPAQUE administration. ( 8.2 ) 8.1 Pregnancy Risk Summary Hysterosalpingography is contraindicated in pregnant women due to the potential risk to the fetus from an intrauterine procedure [see Contraindications (4) ]. There are no data with iohexol use in pregnant women to inform any drug-associated risks. Iohexol crosses the placenta and reaches fetal tissues in small amounts ( see Data ) . In animal reproduction studies, no developmental toxicity occurred with intravenous iohexol administration to rats and rabbits at doses up to 0.4 (rat) and 0.5 (rabbit) times the maximum recommended human intravenous dose ( see Data ). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Human Data Literature reports show that intravenously administered iohexol crosses the placenta and is visualized in the digestive tract of exposed infants after birth.

Metabolism

Following the intravenous administration of iohexol (between 500 mg iodine/kg to 1,500 mg iodine/kg) to 16 adult subjects, apparent first-order terminal elimination half-life was 12.6 hours and total body clearance was 131 (98 to 165) mL/min. Clearance was not dose dependent.

The adverse effects of overdosage in intra-arterial or intravenous administration are life-threatening and affect mainly the pulmonary and cardiovascular systems. The symptoms include: cyanosis, bradycardia, acidosis, pulmonary hemorrhage, convulsions, coma, and cardiac arrest. Treatment of an overdosage is directed toward the support of all vital functions, and prompt institution of symptomatic therapy. Iohexol can be dialyzed.

• Dec 26, 1985NDANDA018956Ge Healthcare
• Oct 24, 1995NDANDA020608Ge Healthcare
• Nov 13, 2025ANDAANDA217737Amneal

1. 1Urticaria99012%
2. 2Pruritus87411%
3. 3Dyspnoea7519.4%
4. 4Sneezing5987.5%
5. 5Erythema5597.0%
6. 6Nausea5046.3%
7. 7Vomiting4645.8%
8. 8Rash4015.0%
9. 9Chills3394.2%
10. 10Cough3123.9%
11. 11Anaphylactic Reaction2973.7%
12. 12Acute Kidney Injury2733.4%
13. 13Hypotension2663.3%
14. 14Contrast Media Reaction2593.2%
15. 15Pyrexia2463.1%

Recent PubMed references pinned to Iohexol as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Evaluation of agmatine efficacy in contrast-induced nephropathy: experimental evidence in rat model.
  Acta cirurgica brasileira · 2026 · Yeniçeri M, Baş S, Şenoymak MC, et al.
  PMID 42154900DOI 10.1590/acb412426
• Iohexol Clearance and Kidney Transplantation: Determinants of Its Variation in Living Kidney Donors One Year After Donation and Impact on Glomerular Filtration Rate Gain in Kidney Recipients.
  Fundamental & clinical pharmacology · 2026 · Arrivé C, Baran N, Tonini J, et al.
  PMID 42002265DOI 10.1111/fcp.70087
• Clearance of mannitol for assessment of glomerular filtration rate in chronic kidney disease: A validation against iohexol clearance.
  Clinical physiology and functional imaging · 2026 · Kiss K, Saeed A, Ricksten SE, et al.
  PMID 41930677DOI 10.1111/cpf.70059
• Iodinated contrast agents decrease the activity of multidrug resistance protein, cell migration, and induce cell death in different tumor cell lines and glioblastoma spheroids.
  Biochimica et biophysica acta. General subjects · 2026 · de Abreu JSS, Castelo-Branco MTL, Fernandes J, et al.
  PMID 41812931DOI 10.1016/j.bbagen.2026.130930
• Direct Measurement of GFR: Who, When, and How?: A Practical Approach Emphasizing Iohexol Plasma Clearance.
  Journal of the American Society of Nephrology : JASN · 2026 · Schaeffner E, Ebert N, White CA, et al.
  PMID 41591826DOI 10.1681/ASN.0000001040
• Accurate Estimation of Glomerular Filtration Rate in Critically Ill Infants and Children Using a Iohexol Population Pharmacokinetic Modeling Approach.
  Clinical pharmacokinetics · 2026 · Dhont E, Destere A, Gerard A, et al.
  PMID 41591642DOI 10.1007/s40262-025-01617-x
• Low-concentration contrast abdominopelvic CT: A comparison with high-concentration contrast CT image quality.
  PloS one · 2026 · Yoon S, Park JH, Sym SJ, et al.
  PMID 41490196DOI 10.1371/journal.pone.0338726
• Iohexol as an Emerging Contaminant Potentially Influencing Structural and Functional Changes in the Activated Sludge Microbiome.
  Molecules (Basel, Switzerland) · 2025 · Nowak A, Pacwa-Płociniczak M, Guzik U, et al.
  PMID 41375236DOI 10.3390/molecules30234641

The 10 most recently updated of 169 ClinicalTrials.gov registrations naming Iohexol as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Optimization of Beta-lactam Dosing in Critically Ill Patients With Cystatin C (OPTIMIZE-GNI)
  Recruiting · Phase 4 · Interventional · 200 enrolled · National Institute of Allergy and Infectious Diseases (NIAID)
  NCT06709521updated 2026-06-12
• Fluorescent Probe for Assessment of Renal Elimination
  Not yet recruiting · Phase 4 · Interventional · 200 enrolled · Aaron Cook
  NCT07643467updated 2026-06-11
• US vs FL-Guided Lumbar Nerve Root Injections
  Recruiting · Interventional · 64 enrolled · Tanta University
  NCT07627308updated 2026-06-04
• Autologous Platelet-rich Plasma Versus Whole Blood for Epidural Patch in Spontaneous Intracranial Hypotension
  Not yet recruiting · Interventional · 218 enrolled · Beijing Tiantan Hospital
  NCT07602556updated 2026-05-27
• Pathogenesis of Kidney Disease in Type 1 Diabetes: a Modern Kidney Biopsy Cohort (The PANDA Study)
  Active not recruiting · Observational · 100 enrolled · University of Colorado, Denver
  NCT05319990updated 2026-05-22
• Ultra-Low Contrast Angiography in AKI
  Recruiting · Phase 3 · Interventional · 32 enrolled · Tulane University
  NCT05906758updated 2026-05-18
• Biopsy of Calcifications Under Contrast Enhancement Guide (BoCCE)
  Completed · Interventional · 184 enrolled · Azienda USL Reggio Emilia - IRCCS
  NCT04862429updated 2026-05-07
• Improving Patient Assessment After Acute Kidney Injury (AKI)
  Recruiting · Observational · 100 enrolled · University of Nottingham
  NCT07569588updated 2026-05-06
• Transgender Analysis of Nephrological Studies Focused on Renal Metrics
  Not yet recruiting · Observational · 60 enrolled · Amsterdam UMC, location VUmc
  NCT07542964updated 2026-04-21
• MediBeacon® Transdermal GFR System for the Evaluation of Kidney Function in Adults With Heart Failure
  Not yet recruiting · Interventional · 15 enrolled · MediBeacon
  NCT07349797updated 2026-04-01

Frequently asked questions

How does Iohexol work?

The iodine atoms in iohexol provide attenuation of X-rays in direct proportion to the concentration of iohexol. Since concentration changes over time, iohexol provides time-dependent image contrast which may assist in visualizing body structures.

What is Iohexol used for?

According to FDA labeling, Iohexol carries indications including: OMNIPAQUE is a radiographic contrast agent indicated for intrathecal, intra-arterial, intravenous, oral, rectal, intraarticular, and body cavity imaging procedures in adults and pediatric patients. ( 1 ) 1.1 Intrathecal Procedures ‡ OMNIPAQUE is indicated for: Myelography and computerized tomography (CT) myelography (lumbar, thoracic, cervical, total columnar) in adults and pediatric patients aged 2 weeks and older CT cisternography in adults and pediatric patients aged 2 weeks and older 1.2 Intra-arterial Procedures ‡ OMNIPAQUE is indicated for: Cardiac ventriculography in adults and pediatric patients Aortography including studies of aorta and its branches in adults and pediatric patients Selective coronary arteriography in adults Cerebral arteriography in adults Peripheral arteriography in adults Intra-arterial digital subtraction angiography (IA-DSA) of the head, neck, abdominal, renal, and peripheral vessels in adults Pulmonary angiography in pediatric patients 1.3 Intravenous Procedures ‡ OMNIPAQUE is indicated for: Excretory urography in adults and pediatric patients CT of the head and body in adults and pediatric patients Peripheral venography (phlebography) in adults Intra…. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Iohexol?

Iohexol is classified as Watersoluble, nephrotropic, low osmolar X-ray contrast media, Radiographic Contrast Agent, Imaging Contrast Activity, X-Ray Contrast Activity.

What are the contraindications for Iohexol?

Iohexol labeling lists contraindications including: OMNIPAQUE for hysterosalpingography is contraindicated during pregnancy or suspected pregnancy, menstruation or when menstruation is imminent, within 6 months after termination of pregnancy, within 30 days after conization or curettage, when signs of infection are present in any portion of the genital tract including the external genitalia, and when reproductive tract neoplasia is known or suspected because of the risk of peritoneal spread of neoplasm. Hysterosalpingography during pregnancy (or suspected pregnancy), menstruation (or when menstruation is imminent), within 6 months after termination of pregnancy, within 30 days after conization or curettage, when signs of infection are present in any portion of the genital tract, including the external genitalia, and when reproductive tract neoplasia is known or suspected.. Always consult the full prescribing information and a clinician.