Medication · Contrast & diagnostic agents

Iodinated contrast agents

Also known as: contrast dye, CT contrast, X-ray contrast medium, iodine contrast

The iodine-containing dyes injected for CT scans and angiography that make blood vessels, organs and tumours show up, generally safe but with a small risk of allergic-type reactions and kidney injury in vulnerable people.

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Generic name
Iodinated contrast agents
Active ingredient
Iodinated contrast agents
Product type
Contrast agent
Drug class
Contrast agents
Brand names
UK Omnipaque, Ultravist, Visipaque · US Omnipaque, Isovue, Visipaque
Routes
Intravenous, Oral, Intra-articular (Intravenous or intra-arterial injection; oral or into a body cavity for some studies)
Dosage forms
Injection, Solution
Also known as
contrast dye, CT contrast, X-ray contrast medium, iodine contrast
Forms
Injection given by the radiology team during the scan; the dose depends on the examination and body weight
Onset and duration
Immediate; a warm flush and metallic taste are common during the injection. Cleared by the kidneys over hours.
Terminology
ATC V08AB
Monitoring
Kidney function (creatinine/eGFR) before the scan in at-risk people and after if indicated; observation for a reaction during and shortly after the injection.

Availability by country

CountryStatusNoteSource
UKHospital onlyAdministered by the radiology team during imaging UK

Legal status differs between countries and can change; each row cites the document it was taken from and applies only to the country named.

What it is used for

  • Making blood vessels, organs and abnormal tissue visible on CT scans
  • Angiography and coronary angiography under X-ray
  • Some X-ray examinations of the urinary tract, gut and joints

How it works in the body

Iodine atoms absorb X-rays strongly. Injected into the bloodstream, the contrast medium briefly fills vessels and perfuses organs, so those structures block more X-rays and appear bright on the image while the surrounding tissue stays darker; timing the scan to the arterial or venous phase shows different things. The molecules are not metabolised and are removed by the kidneys within hours.

Common side effects

  • A warm feeling, flushing and a metallic taste during the injection
  • Feeling sick, a mild rash or itching

Serious: seek help

  • Allergic-type reactions, from hives to, rarely, anaphylaxis
  • Acute kidney injury in people with pre-existing kidney disease, dehydration or diabetes
  • Leakage into the tissues at the injection site
  • Effects on thyroid function in people with thyroid disease

Cautions and interactions

  • Kidney function is checked before the scan in people at risk; extra fluids may be given
  • A previous contrast reaction, severe allergy or asthma is declared beforehand
  • Metformin may be paused around the scan in people with reduced kidney function (the radiology team advises)
  • Thyroid disease and planned radioactive iodine treatment
  • Pregnancy: used only when the scan is essential

Interactions

Check interactions

Taking Iodinated contrast agents with other medicines? Add them to the checker to see what the official sources say about each pair: the mechanism, general management and monitoring, never a bare "safe".

Check Iodinated contrast agents interactions

Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.

No pair records for this medicine are in the sources currently represented by Anatomy Nexus. Absence from this list does not mean no interaction exists.

Contrast or diagnostic agent profile

Agent class
Non-ionic iodinated contrast medium (e.g. iohexol, iopromide, iodixanol)
Used with
CT scan, Fluoroscopy and angiography, X-ray
Route into the body
Injected into a vein (or artery for angiography); sometimes swallowed or instilled into a body cavity

Same-class and related medicines

Same class: Contrast agents

barium sulfategadolinium-based contrast agentsultrasound microbubble contrast

Medicines that share the class of Iodinated contrast agents. They are separate medicines with their own licences, doses and interactions, not alternative names for Iodinated contrast agents.

Related medicines

Medicines often discussed alongside Iodinated contrast agents: used together, compared with it, or acting on the same problem by a different route.

Educational content. Anatomy Nexus provides medical education and does not replace professional medical advice, diagnosis, treatment, prescribing or pharmacist review. Doses, choices and monitoring are decided by a prescriber for an individual; never start, stop or change a medicine on the basis of this page.