From the Guidelines
Iodinated contrast media should be used with caution in patients with severe renal impairment, and the lowest possible dose of contrast medium should be used in patients at risk for contrast-induced acute kidney injury (CI-AKI), as recommended by the KDIGO guideline 1. When administering iodinated contrast media, typical doses range from 50-150 mL depending on the procedure, patient size, and specific contrast agent concentration.
- Patients should be screened for risk factors including previous contrast reactions, severe renal impairment (eGFR <30 mL/min/1.73m²), and metformin use.
- For patients with mild to moderate contrast allergy history, premedication with prednisone (50 mg orally at 13,7, and 1 hour before procedure) and diphenhydramine (50 mg orally 1 hour before) is recommended.
- Adequate hydration before and after contrast administration helps prevent contrast-induced nephropathy, and intravenous volume expansion with either isotonic sodium chloride or sodium bicarbonate solutions is recommended in patients at increased risk for CI-AKI 1.
- The use of iso-osmolar or low-osmolar iodinated contrast media is recommended in patients at increased risk of CI-AKI, as they have a lower risk of contrast-induced nephropathy compared to high-osmolar contrast media 1.
- The mechanism of contrast enhancement relates to the high atomic number of iodine, which attenuates X-rays more effectively than surrounding tissues, creating the desired contrast effect on images.
- Potential adverse reactions include mild effects like warmth, nausea, and vomiting, or severe reactions such as anaphylaxis, which requires immediate treatment with epinephrine, antihistamines, and supportive care.
- Recent studies have shown that the risk of adverse events associated with low-dose iohexol administration for GFR measurement is low, and that shellfish allergy or an allergic-like reaction to topical povidone-iodine is not a contraindication for use of iohexol for GFR measurement 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Iodinated Contrast Media Overview
- Iodinated contrast media (ICM) are commonly used in medical imaging procedures, such as computed tomography (CT) scans, to enhance image quality and provide better diagnostic information.
- However, ICM can cause adverse reactions, ranging from mild to severe, in some patients.
Adverse Reactions to Iodinated Contrast Media
- A study published in 2025 2 found that the overall incidence of adverse reactions to ICM was 0.66%, with severe reactions occurring in 0.05% of patients.
- The same study found that 90.22% of adverse reactions occurred within 20 minutes after injection, and that iodixanol was associated with a higher incidence of adverse reactions compared to other ICM.
- Another study published in 2013 3 discussed the importance of identifying patients at high risk for adverse reactions to ICM and implementing protocols to prevent or reduce the occurrence of these reactions.
Prevention and Management of Adverse Reactions
- A study published in 2024 4 found that implementing best practices for the prevention and management of allergic-like reactions to ICM can lead to a significant reduction in the incidence of these reactions.
- The study found that compliance with best practices increased from 27.66% to 60% after implementation of the project, and that the overall incidence of adverse reactions decreased from 0.56% to 0.19%.
- A study published in 2008 5 compared the nephrotoxicity of iodixanol and iohexol, two commonly used ICM, and found that there was no significant difference in the rates of contrast nephropathy or mortality between the two groups.
Comparison of Iodixanol and Iohexol
- A study published in 2016 6 compared the safety and image quality of iodixanol and iohexol in adult body CT scanning, and found that iodixanol was associated with a lower incidence of adverse reactions compared to iohexol.
- The study found that the total adverse reactions occurred in less than 1% of individuals receiving iodixanol, compared to 2.5% in the iohexol group, and that there were no detectable differences in image quality between the two contrast groups.
- Another study published in 2025 2 found that iohexol was associated with a lower incidence of adverse reactions in patients with non-ICM allergies history, compared to iodixanol.