Omnipaque Side Effects Center

Last updated on RxList: 8/12/2021
Omnipaque Side Effects Center

What Is Omnipaque?

Omnipaque (iohexol injection) is a radiographic contrast medium indicated for intrathecal administration in adults including myelography (lumbar, thoracic, cervical, total columnar) and in contrast enhancement for computerized tomography (myelography, cisternography, ventriculography).

What Are Side Effects of Omnipaque?

Common side effects of Omnipaque include:

  • headache,
  • mild to moderate pain including backache, neck ache and stiffness,
  • nerve pain,
  • nausea,
  • vomiting,
  • fever,
  • hives,
  • stomach upset or pain,
  • visual hallucinations, and
  • neurological changes.

Dosage for Omnipaque

The dose of Omnipaque depends on the degree and extent of contrast required in the area(s) under examination and on the equipment and technique employed.

What Drugs, Substances, or Supplements Interact with Omnipaque?

Omnipaque may interact with phenothiazines, MAO inhibitors, tricyclic antidepressants, CNS stimulants, or psychoactive drugs (analeptics, major tranquilizers, or antipsychotic drugs). Tell your doctor all medications and supplements you use.

Omnipaque During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before receiving Omnipaque. It is unknown if Omnipaque passes into breast milk. Bottle feedings may be substituted for breastfeedings for 24 hours following administration of Omnipaque. Consult your doctor before breastfeeding.

Additional Information

Our Omnipaque (iohexol injection) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Digestive Disorders: Common Misconceptions See Slideshow
Omnipaque Professional Information


The following clinically significant adverse reactions are described elsewhere in the labeling:

  • Risks Associated with Inadvertent Intrathecal Administration [see WARNINGS AND PRECAUTIONS]
  • Risks Associated with Inadvertent Parenteral Administration [see WARNINGS AND PRECAUTIONS]
  • Hypersensitivity Reactions [see WARNINGS AND PRECAUTIONS]
  • Contrast Induced Kidney Injury [see WARNINGS AND PRECAUTIONS]
  • Cardiovascular Adverse Reactions [see WARNINGS AND PRECAUTIONS]
  • Thromboembolic Events [see WARNINGS AND PRECAUTIONS]
  • Severe Cutaneous Reactions [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Intrathecal Administration



In controlled clinical studies involving 1531 patients using OMNIPAQUE the following adverse reactions were reported:
System Organ Class Adverse Reaction Incidence
Nervous System Headaches 18%
Musculoskeletal and Connective Tissue Pain including backache, neckache, stiffness and neuralgia 8%
Gastrointestinal System Nausea 6%
Vomiting 3%
Nervous System Dizziness 2%
Other Reactions Feeling of heaviness, hypotension, hypertonia, sensation of heat, sweating, vertigo, loss of appetite, drowsiness, hypertension, photophobia, tinnitus, neuralgia, paresthesia, difficulty in micturition, and neurological changes <0.1%

Pediatric Patients


In clinical studies involving 152 patients for pediatric myelography by lumbar puncture, adverse events following the use of OMNIPAQUE 180 were generally similar to those reported in adults.
Procedure System Organ Class Adverse Reaction Incidence
Myelography by LumbarPuncture Nervous System Headache 9%
Gastrointestinal System Vomiting 6%
Musculoskeletal and Connective Tissue Backache 1.3%

Other Reactions

All were transient and mild with no clinical sequelae

Fever <0.7%
Visual Hallucination
Neurological Changes

Intravascular Administration

Immediately following intravascular injection of contrast medium, a transient sensation of mild warmth is not unusual. Warmth is less frequent with OMNIPAQUE than with ionic contrast media.


In controlled clinical studies involving 1485 patients, the following adverse reactions occurred (Table 25).


System Organ Class Adverse Reaction Incidence
Cardiovascular System Arrhythmias including PVCs and PACs (2%), 2%
Hypotension 0.7%
Others including cardiac failure, asystole, bradycardia, tachycardia, and vasovagal reaction ≤ 0.3%
Nervous System Vertigo (including dizziness and lightheadedness) 0.5%
Pain 3%
Vision Abnormalities (including blurred vision and photomas) 2%
Taste Perversion 1%
Other Reactions Anxiety, fever, motor and speech dysfunction, convulsion, paresthesia, somnolence, stiff neck, hemiparesis, syncope, shivering, transient ischemic attack, cerebral infarction, and nystagmus Individual incidence of 0.3% or less
Respiratory System Dyspnea, rhinitis, coughing, and laryngitis Individual incidence of 0.2% or less
Gastrointestinal System Nausea 2%
Vomiting 0.7%
Others including diarrhea, dyspepsia, cramp, and dry mouth Individual incidence of less than 0.1%.
Skin and Subcutaneous Tissues Urticaria 0.3%
Purpura 0.1%
Abscess 0.1%
Pruritus 0.1%

Pediatric Patients

In controlled clinical studies involving 391 patients for pediatric angiocardiography, urography, and CT head imaging, adverse reactions following the use of OMNIPAQUE 240, 300, and 350 were generally similar in quality and frequency to those reported in adults (Table 26).


System Organ Class Adverse Reaction Incidence
Cardiovascular System Ventricular Tachycardia 0.5%
2:1 Heart Block 0.5%
Hypertension 0.3%
Anemia 0.3%
General Disorders and Administration Site Conditions Pain 0.8%
Fever 0.5%
Nervous System Convulsion 0.3%
Taste Abnormality 0.5%
Respiratory System Congestion 0.3%
Apnea 0.3%
Gastrointestinal System Nausea 1%
Vomiting 2%
Endocrine System Hypoglycemia 0.3%
Skin and Subcutaneous Tissue Rash 0.3%

Oral Administration For Examination Of The Gastrointestinal Tract


Nausea, vomiting, and diarrhea have been most frequently reported following orally administered undiluted OMNIPAQUE for radiographic examination of the gastrointestinal tract. In controlled clinical studies involving 54 adult patients for oral radiographic examination of the gastrointestinal tract using undiluted OMNIPAQUE 350 the following adverse reactions were reported (Table 27).


System Organ Class Adverse Reaction Incidence
Gastrointestinal System Diarrhea 42%
Nausea 15%
Vomiting 11%
Abdominal Pain 7%
Flatulence 2%
Nervous System Headache 2%

Pediatrics Patients (Oral and Rectal Administration)

In clinical studies involving 58 pediatric patients, the adverse reactions were found to mostly affect the gastrointestinal system with diarrhea (36%), vomiting (9%), nausea (5%) and abdominal pain (2%). However, fever (5%), hypotension (2%) and urticaria (2%) were also reported.

Oral Administration For CT Of The Abdomen In Conjunction With Intravenous Administration


In a controlled clinical study involving 44 adult patients receiving oral administration of diluted OMNIPAQUE (4-9 mg iodine/mL) in conjunction with intravenously injected OMNIPAQUE 300 for CT examination of the abdomen, adverse reactions were limited to a single report of vomiting.

Pediatric Patients

In clinical studies involving 69 pediatric patients receiving oral administration of diluted OMNIPAQUE (9-29 mg iodine/mL) in conjunction with intravenously administered OMNIPAQUE 240 and OMNIPAQUE 300 for CT examination of the abdomen, adverse reactions were limited to a single report of vomiting (1.4%).

Body Cavity Use


Arthrography: In controlled clinical studies involving 285 adult patients for various body cavity examinations using OMNIPAQUE 240, 300 and 350, the most frequent adverse reactions were administration site reactions: pain 26% and swelling 22%, were exclusively reported for arthrography and were generally related to the procedure rather than the contrast medium. Patients also experienced heat (7%). All other adverse reaction occurred at a rate less than or equal to 1%.

Pediatric Patients

No adverse reactions associated with the use of OMNIPAQUE for VCU procedures were reported in 51 pediatric patients studied.

Post-Marketing Experience

The following additional reactions listed by indication have been identified during post-approval use of OMNIPAQUE. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.


Immune System Disorders: Hypersensitivity reactions, anaphylactic or anaphylactoid reactions, anaphylactic or anaphylactoid shock including life-threatening or fatal anaphylaxis.

General Disorders and Administration Site Conditions: Pyrexia, chills, pain and discomfort, asthenia, administration site conditions including extravasation.

Intrathecal Administration

Nervous System Disorders: Meningism, aseptic meningitis, seizures or status epilepticus, disorientation, coma, depressed or loss of consciousness, transient contrast-induced toxic encephalopathy (including amnesia, hallucination, paralysis, paresis, speech disorder, aphasia, dysarthria), restlessness, tremors, hypoesthesia.

Musculoskeletal and Connective Tissue Disorders: Pain, muscle spasms or spasticity.

Psychiatric Disorders: Confusional state, agitation, anxiety.

Eye Disorders: Transient visual impairment including cortical blindness.

Renal Reactions: Acute kidney injury.

Intravascular Administration

Cardiovascular Disorders: Severe cardiac complications (including cardiac arrest, cardiopulmonary arrest), shock, peripheral vasodilatation, palpitations, vasospasm including spasm of coronary arteries, myocardial infarction, syncope, cyanosis, pallor, flushing, chest pain.

Hemodynamic Reactions: Vasospasm and thrombophlebitis following intravenous injection.

Blood and Lymphatic System Disorders: Neutropenia.

Nervous System Disorders: Disorientation, coma, depressed or loss of consciousness, transient contrast-induced toxic encephalopathy (including amnesia, hallucination, paralysis, paresis, speech disorder, aphasia, dysarthria), restlessness, tremors, hypoesthesia.

Psychiatric Disorders: Confusional state, agitation.

Eye Disorders: Eye irritation or itchiness, periorbital edema, ocular or conjunctival hyperemia, lacrimation.

Renal Reactions: Acute kidney injury, toxic nephropathy (CIN), transient proteinuria, oliguria or anuria, increased serum creatinine.

Gastrointestinal Disorders: Abdominal pain, pancreatitis aggravated, salivary gland enlargement.

Endocrine Reactions: Hyperthyroidism. Thyroid function tests indicative of hypothyroidism or transient thyroid suppression have been uncommonly reported following iodinated contrast media administration to adult and pediatric patients, including infants. Some patients were treated for hypothyroidism.

Respiratory; Thoracic, and Mediastinal Disorders: Respiratory distress, respiratory failure, pulmonary edema, bronchospasm, laryngospasm, throat irritation, throat tightness, laryngeal edema, wheezing, chest discomfort, asthmatic attack.

Skin and Subcutaneous Tissue Disorders: Contrast media reactions range from mild (e.g. pleomorphic rashes, drug eruption, erythema and skin discoloration, blisters, hyperhidrosis, angioedema, localized areas of edema) to severe: [e.g. Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN), bullous or exfoliative dermatitis, acute generalized exanthematous pustulosis (AGEP) and drug reaction with eosinophilia and systemic symptoms (DRESS)].

Oral Administration

Gastrointestinal Disorders: Dysphagia, abdominal pain.

Body Cavity Administration

Gastrointestinal Disorders: Pancreatitis.

Musculoskeletal and Connective Tissue Disorders: Arthritis (arthrography).

Hysterosalpingography: Injection of OMNIPAQUE for hysterosalpingography is associated with immediate, transient pain. Monitor injection pressure and volume instilled to minimize pain and to avoid disruptive distention of the uterus and fallopian tubes. Fluoroscopic monitoring is recommended.
Nervous system: Pain (49%), somnolence and fever each with an individual incidence of 3%.
Gastrointestinal system: Nausea (3%).


Drug-Drug Interactions


In patients with renal impairment, metformin can cause lactic acidosis. Iodinated contrast agents appear to increase the risk of metformin-induced lactic acidosis, possibly as a result of worsening renal function. Stop metformin at the time of, or prior to, OMNIPAQUE administration in patients with an eGFR between 30 and 60 mL/min/1.73 m2; in patients with a history of hepatic impairment, alcoholism or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate eGFR 48 hours after the imaging procedure, and reinstitute metformin only after renal function is stable.

Radioactive Iodine

Administration of iodinated contrast agents may interfere with thyroid uptake of radioactive iodine (I-131 and I-123) and decrease therapeutic and diagnostic efficacy in patients with carcinoma of the thyroid. The decrease in efficacy lasts for 6-8 weeks.

Beta-Adrenergic Blocking Agents

The use of beta-adrenergic blocking agents lowers the threshold for and increases the severity of contrast reactions and reduces the responsiveness of treatment of hypersensitivity reactions with epinephrine. Because of the risk of hypersensitivity reactions, use caution when administering OMNIPAQUE to patients taking beta-blockers.

Drugs That Lower Seizure Threshold

Drugs that lower seizure threshold, especially phenothiazine derivatives including those used for their antihistaminic or antinauseant properties, are not recommended for use with intrathecal administration of OMNIPAQUE.

CNS Active Drugs

Drugs such as monoamine oxidase (MAO) inhibitors, tricyclic antidepressants, CNS stimulants, psychoactive drugs described as analeptics, major tranquilizers, or antipsychotic drugs. Such medications should be discontinued at least 48 hours before myelography, should not be used for the control of nausea or vomiting during or after myelography, and should not be resumed for at least 24 hours post procedure. In non-elective procedures in patients on these drugs, consider prophylactic use of anticonvulsants

Drug Laboratory Test Interactions

Effect On Thyroid Tests

If iodine-containing isotopes are to be administered for the diagnosis of thyroid disease, the iodine-binding capacity of thyroid tissue may be reduced for up to 2 weeks after contrast medium administration. Thyroid function tests that do not depend on iodine estimation, e.g., T3 resin uptake or direct thyroxine assays, are not affected.

Read the entire FDA prescribing information for Omnipaque (Iohexol Injection)


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© Omnipaque Patient Information is supplied by Cerner Multum, Inc. and Omnipaque Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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