iohexol

Iohexol is a nonionic water-soluble contrast agent used for X-ray (radiographic) imaging. Iohexol may be administered orally or as an injection depending on the type of radiologic procedure required. The iodine compounds in the solution block the X-rays and produce opacity and delineate the body structures the solution passes through, enabling radiographic visualization of the blood vessels, spinal canal, or other body cavities or structures.

The uses of iohexol injections include:

• Intrathecal injection into the spinal canal for imaging of the spinal canal (myelography)
• Intravascular injection into an artery or a vein
• CT scanning of the body
• Digital subtraction angiography of the brain
• Excretory urography for upper urinary tract disease
• Opacification of gastrointestinal tract and contrast enhanced CT (CECT) scan of abdomen, in combination with oral iohexol
• Intravenous (IV) infusion for body imaging
• Intracavity instillation for imaging of the uterus and fallopian tubes (hysterosalpingography)

• Do not administer iohexol to patients with a known hypersensitivity to iodinated contrast agents, including iohexol.
• The different formulations intended for specific routes of administration are not interchangeable. Administration of iohexol formulation through a route it is not indicated for can result in severe, life-threatening reactions.
• Administration of oral iohexol through other routes can cause sepsis. Do not administer oral solution 9 and 12 through any route other than oral (parenteral).
• Oral administration of iohexol can draw fluid into the intestines, and if severe enough, it can cause low blood volume (hypovolemia).
• Warnings specific to intrathecal administration:
  • Do not administer Omnipaque 140 and 350 intrathecally. Intrathecal administration of iohexol not meant for intrathecal use can result in convulsions, paralysis, cerebral hemorrhage, kidney failure, coma, cardiac arrest and death.
  • Do not perform myelography in the presence of significant bacterial infection where bacteremia is likely.
  • Do not administer corticosteroids intrathecally with iohexol.
  • Do not immediately repeat myelography in the event of technical failure, because of the possibility of iohexol overdose.
  • If the cerebrospinal fluid (CSF) is grossly bloody, consider the risks and benefits of myelography.
  • Use with caution in patients with a history of epilepsy, severe cardiovascular disease, chronic alcoholism, or multiple sclerosis.
  • Use with extra caution in elderly patients and adjust dose appropriately.
  • Patients receiving anticonvulsants should continue to be maintained on the therapy. In patients with a history of seizure activity or those at risk for seizure, pretreatment with barbiturates may be considered. Drugs that lower seizure threshold should not be used with iohexol.
• Administration of iodinated contrast agents and diagnostic procedures with the use of these agents should be performed only under the direction of personnel specifically trained for these procedures. Competent personnel and emergency facilities should be readily available to handle any complication that may arise from the procedure or any reaction to iohexol.
• Administration of iohexol can cause life-threatening hypersensitivity reactions, and the risk is relatively higher in patients who have allergic disorders such as asthma, or those who previously had a reaction to any iodinated contrast agent.
  • Premedication with antihistamines or corticosteroids may be performed to minimize the risk of hypersensitivity reactions.
  • Appropriate facilities and competent personnel for emergency treatment of hypersensitivity reactions should be available for at least 30 to 60 minutes after iohexol administration.
• Patients should be well hydrated prior to and following administration of any contrast medium, including iohexol.
• Iohexol may cause acute kidney injury (contrast-induced nephropathy). Use with caution in combined kidney/liver disease, and avoid use in patients with no urine output (anuria). Risk factors include older age, impaired kidney function, diabetes, dehydration, multiple myeloma, congestive heart failure (CHF) or severe arterial/venous disease.
• Iohexol may cause hyperthyroidism or hypothyroidism, evaluate the patient’s thyroid function 3 weeks after administration of iohexol.
• Iodinated contrast agents can alter the results of thyroid function tests. If thyroid function tests are necessary, they must be performed prior to iohexol administration.
• If repeat tests with contrast agents are required, allow a suitable time interval for normal clearance of the drug from the body.
• Life-threatening, sometimes fatal cardiovascular events have occurred and the risk is higher in patients with cardiovascular disease. Emergency resuscitation equipment and trained personnel should be available during intravascular administration.
• Take particular care to avoid drug leakage from the blood vessel, iohexol can damage the surrounding tissue and lead to tissue necrosis or cause compartment syndrome.
• There have been reports of life-threatening skin reactions including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), acute generalized exanthematous pustulosis (AGEP) and drug reaction with eosinophilia and systemic symptoms (DRESS). Avoid use of iohexol in patients with a history of severe skin reactions.
• Use with caution in patients with myasthenia gravis and monitor for worsening of the condition.
• Iodinated contrast agents can cause hypertensive crises in patients with neuroendocrine tumors such as pheochromocytoma and paraganglioma. Use with caution, adjust dosage and monitor blood pressure
• Use with caution in sickle cell disease, iohexol may promote sickling.
• Contrast agent use in excretory urography may cause temporary suppression of urine formation. Allow suitable intervals before a repeat procedure, especially in patients with reduced renal function.
• Hysterosalpingography should not be performed in the following conditions:
  • During menstruation or when it is imminent
  • Presence of infection in the genital tract
  • Pregnancy or suspected pregnancy
  • Up to 6 months after pregnancy termination
  • Up to 30 days after conization or curettage
• In patients with carcinoma or suspected carcinoma, exercise caution in performing hysterosalpingography to avoid spreading of the lesion.

Common side effects of iohexol include:

• Headache
• Nerve pain (neuralgia)
• Nausea
• Vomiting
• Mild to moderate pain including:
  • Backache
  • Neck ache
• Stiffness
• Skin reactions including:
  • Rash
  • Hives (urticaria)
  • Itching (pruritus)
  • Redness (erythema)
  • Skin discoloration
  • Stevens-Johnson syndrome
  • Toxic epidermal necrolysis
  • Acute generalized exanthematous pustulosis (AGEP)
  • Drug reaction with eosinophilia and systemic symptoms (DRESS)
• Hypersensitivity reactions including:
  • Severe allergic reaction (anaphylaxis), including fatal
  • Anaphylactic shock
• High temperature (pyrexia)
• Chills
• Pain and discomfort
• Weakness (asthenia)
• Leakage of the drug from the blood vessel (extravasation)
• Underactive or overactive thyroid (hyperthyroidism/hypothyroidism)

Side effects specific to administration routes:

Intravascular and intrathecal administration

• Disorientation
• Loss of consciousness
• Coma
• Transient contrast-induced toxic encephalopathy with symptoms such as:
  • Memory loss (amnesia)
  • Hallucination
  • Speech impairment (dysarthria)
  • Language impairment (aphasia)
  • Muscle weakness (paresis)
  • Paralysis
• Reduced skin sensation (hypoesthesia)
• Restlessness
• Tremor
• Confusion
• Agitation
• Acute kidney injury

Intrathecal administration

• Irritation of the membrane around the spinal cord and brain (meningism)
• Aseptic inflammation of the meninges (meningitis)
• Seizures
• Prolonged seizures (status epilepticus)
• Pain
• Muscle spasms
• Muscle stiffness (spasticity)
• Anxiety
• Transient visual impairment

Intravascular administration

• Chest pain
• Palpitations
• Heart attack (myocardial infarction)
• Cardiac arrest
• Cardiopulmonary arrest
• Shock
• Spasm of blood vessels including the coronary arteries
• Dilation of peripheral blood vessels
• Fainting (syncope)
• Skin pallor
• Flushing
• Bluish skin color due to low oxygen (cyanosis)
• Vein inflammation with blood clot (thrombophlebitis)
• Low count of neutrophil immune cells (neutropenia)
• Contrast-induce nephropathy (CIN)
• Increase in serum creatinine
• Protein excretion in urine (proteinuria)
• Reduced urine output (oliguria)
• Absence of urine output (anuria)
• Abdominal pain
• Aggravated pancreas inflammation (pancreatitis)
• Salivary gland enlargement
• Eye irritation or itching
• Swelling around the eyes (periorbital edema)
• Redness of the eye
• Watering of eyes (lacrimation)

Injection for hysterosalpingography

• Immediate, transient pain
• Nausea
• Fever
• Drowsiness (somnolence)

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Injection solution

• 180 mg/mL
• 240 mg/mL
• 300 mg/mL

Intravenous solution

• 140 mg/mL
• 350 mg/mL

Powder for oral solution (Oraltag)

• 9.7 g/bottle (equivalent to 4.5 g carbon bound iodine)
• The packaging allows for preparation of the iohexol in a single-use bottle
• There are 5 fill lines premolded on the bottle for accurate dilution of the product to a desired concentration

Adult:

Intrathecal

Omnipaque 180 (180 mgI/mL)

• Lumbar Myelography, via lumbar injection 10-17 mL
• Cervical Myelography, via C1-C2 injection: 7-12.5 mL

Omnipaque 240 (240 mgI/mL)

• Lumbar Myelography, via lumbar injection: 7-12.5 mL
• Thoracic Myelography, via lumber/cervical injection: 6-12.5 mL
• Cervical Myelography, via lumbar injection: 6-12.5 mL; via C1-C2 injection: 6-12.5
• Total Columnar Myelography, via lumbar injection: 6-12.5 mL

Omnipaque 300 (300 mgI/mL)

• Thoracic Myelography, via lumbar/cervical injection: 6-10 mL
• Cervical Myelography, via lumbar injection: 6-10 mL; via C1-C2 injection: 4-10 mL
• Total Columnar Myelography, via lumbar injection: 6-10 mL

Administration

• Rate of injection: Slowly over 1-2 min
• Not to exceed 300 mg/mL or 3060 mg iodine per single myelographic procedure

Intravascular

Omnipaque 140/300/350

Angiocardiography: ventriculography, pulmonary arteriography, venography and studies of collateral arteries

• Ventriculography: 40 mL, range of 30-60 mL; may be repeated as needed, not to exceed 250 mL
• Selective Coronary Arteriography: 5 mL. range 3-14 mL per injection
• Aortic Root and Arch Study: 50 mL, range 20-75 mL, when used alone
• Pulmonary Angiography: 1 mL/kg
• Combined Angiographic Procedures: Multiple Procedures not to exceed 5 mL/kg or 250 mL
• Aortography and Selective Arteriography
• Aorta: 50-80 mL
• Major branches incl celiac, mesenteric arteries: 30-60 mL
• Renal arteries: 5-15 mL; not to exceed 291 mL/Omnipaque 300 or 250 mL/Omnipaque 350 when repeat injection indicated
• Cerebral Arteriography: Common Carotid Artery: 6-12 mL
• Internal Carotid Artery: 8-10 mL
• External Carotid Artery: 6-9 mL
• Vertebral Artery: 6-10 mL

CT Scanning of the Body

• Head Imaging via injection: 70-150 mL (Omni 300); 80 mL (Omni 350)
• Head Imaging via infusion: 120-250 mL (Omni 240)
• Body Imaging via injection: 50-200 mL (Omni 300); 60-100 mL (Omni 350)

Digital Subtraction

Omni 350

• Usual amount used for IV digital technique is 30-50 mL
• Administer as bolus at 7.5-30 mL/sec using pressure injector

Omni 140

• Intra-arterial use for head, neck, abdominal, renal, and peripheral vessel
• Administer 1 or more bolus via intra-arterial injection of Omni 140
• Aorta: 20-45 mL at 8-20 mL/sec
• Carotid: 5-10 mL at 3-6 mL/sec
• Femoral: 9-20 mL at 3-6 mL/sec
• Vertebral: 4-10 mL at 2-8 mL/sec
• Renal: 6-12 mL at 3-6 mL/sec
• Other Branches of Aorta: 8-25 mL at 3-10 mL/sec

Excretory Urography

• Omnipaque 300/350: 200-350 mgI/kg body weight  

Oral

Oraltag

• Indicated for opacification of the GI tract during CT of the abdomen and pelvis
• 1-2 bottles of prepared solution (4.5-9 g iodine) orally 20-60 minutes before image acquisition

Omnipaque 240/300/350

• GI Tract
  • Omni 350 (undiluted): 50-100 mL, dependent on nature of procedure and patient size
• CECT of abdomen
  • Omni 300: Dilute oral dose to 6-9 mg(iodine)/mL and administer in combo with intravenous (IV) dose
  • Recommended oral dose: 500-1000 mL
  • Recommended IV dose: 100-150 mL
  • Administer oral dose 20-40 min prior to IV dose

Intracavity

• Usual: 50-150 mL IV OR 100-250 mL IV of (240 mgI/mL)

Hysterosalpingography

• Omnipaque 240: 15-20 mL, but varies with anatomy and/or disease state
• Omnipaque 300: 15-20 mL, but varies with anatomy and/or disease state

Body Imaging

• 25-75 mL IV OR 50-150 mL IV infusion; not to exceed 150 mL
• For 240 mg/mL: 35-100 mL IV OR 70-200 mL IV infusion; not to exceed 250 mL

Geriatric:

• In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy

Pediatric:

Intrathecal

• Recommended total doses for lumbar, thoracic, cervical, and/or total columnar myelography

Omnipaque 180 (180 mgI/mL)

• Children 0 to under 3 months: 2-4 mL
• Children 3 to under 36 months: 4-8 mL
• Children 3 to under 7 years: 5-10 mL
• Children 7 to under 13 years: 5-12 mL
• Children 13-18 years: 6-15 mL

Administration

• Rate of injection: Slowly over 1-2 min
• Not to exceed 180 mg/mL or 2700 iodine per single myelographic procedure

Intravascular

Omnipaque 240/300/350

Angiocardiography: ventriculography, pulmonary arteriography, venography and studies of collateral arteries

• Ventriculography: Omnipaque 350: 1.25 mL/kg, range 1-1.5 mL/kg; not to exceed 5 mL/kg or 250 mL, when multiple injections given
• Omnipaque 300: 1.75 mL/kg, range 1.5-2 mL/kg; not to exceed 6 mL/kg or 291 mL, when multiple injections given
• Pulmonary Angiography: 1 mL/kg
• Combined Angiographic Procedures - Multiple Procedures
  • Omnipaque 350: Not to exceed 5 mL/kg or 250 mL
  • Omnipaque 300: Not to exceed 6 mL/kg or 291 mL
• Aortography and selective arteriography: 1 mL/kg single injection dose; not to exceed 5 mL/kg or 250 mL

CT Scanning of the Body

• Head imaging: 1-2 mL/kg; not to exceed 28 gI (Omni 240) or 35 gI Omni 300
• Head imaging via infusion: 120-250 mL (Omni 240)
• Body imaging via injection: 50-200 mL (Omni 300); 60-100 mL (Omni 350)

Excretory Urography

• Omnipaque 300: 0.5-3 mL/kg of body weight
• Infants/children: According to age and body weight
• Usual dose: 1-1.5 mL/kg; not to exceed 3 mL/kg

Oral

Oraltag

• Indicated for opacification of the GI tract during CT of the abdomen and pelvis
• Children below 3 years
  • Up to 4.5 g of iodine orally 20-60 minutes before image acquisition
  • From portion of 1 bottle of prepared solution; 120-300 mL, depending on size of the patient
• Children 3-18 years
  • Up to 9 g of iodine orally 20-60 minutes before image acquisition
  • From less than 1 bottle up to 2 bottles of prepared solution; 280-750 mL, depending on size of patient

Omnipaque 180/240/300 mg (iodine)/mL

• GI tract
  • For oral pass through, dependent on nature of procedure and patient size
  • Children below 3 months: Omnipaque 180: 5-30 mL
  • Children 3 months to 3 years: Omnipaque 180/240/300: up to 60 mL
  • Children 4-10 years: Omnipaque 180/240/300: up to 80 mL
  • Children above 10 years: Omnipaque 180/240/300: up to 100 mL
  • When given rectally, larger volumes may be used
• CECT of abdomen
  • Omni 300: dilute oral dose to concentration of 9-21 mgI/mL (180-750 mL) and administer in combo with IV dose
  • Children below 3 years: Not to exceed 5 gI
  • Children 3-18 years: Not to exceed 10 gI
  • Give total oral dose all at once or over 30-45 minutes, if there is difficulty consuming
• Recommended IV dose, given in conjunction with dilute oral dose, of Omni 240/300
  • Recommended oral dose: 180-750 mL
  • Recommended IV dose: 2 mL/kg; range 1-2 mL/kg; not to exceed 3 mL/kg
  • Administer oral dose 30-60 minutes prior to IV dose

Overdose

• Iohexol overdose can be life-threatening and mainly affect the cardiovascular and pulmonary systems. Overdose symptoms may include bluish color of skin (cyanosis) from low oxygen levels, slow heart rate (bradycardia), excessive acidity of body fluids (acidosis), pulmonary hemorrhage, convulsions, coma and cardiac arrest.
• Iohexol overdose treatment includes immediate institution of symptomatic and supportive therapy, including continuous monitoring and support of all vital functions.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Severe interactions of iohexol include:
  • sodium iodide I 131
• Serious interactions of iohexol include:
  • agents with seizure threshold lowering potential
  • metformin
• Moderate interactions of iohexol include:
  • aldesleukin
  • loop diuretics
  • iohexol has no known mild interactions with other drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• Animal reproductive studies do not show evidence of fertility impairment or fetal harm, however, there are no controlled studies in pregnant women. Use of iohexol during pregnancy should be limited to only when it is clearly needed.
• It is not known to what extent orally administered iohexol is present in breastmilk. Iohexol may be used in breastfeeding women after considering mother’s clinical need and the developmental and health benefits from breastfeeding and the potential risks to the fetus. The nursing mother may consider pumping and discarding the milk for 10 hours after iohexol administration to minimize risk of exposure to the breastfed infant.
• Intravenous iohexol is present in breastmilk at concentrations of approximately 0.5% of the maternal dose. Breastfeeding should be interrupted for 24 hours after IV administration of iohexol.

• Inform your physician immediately if you experience any hypersensitivity reactions following administration of iohexol.