It's better for patients who have experienced allergic reactions to iodinated contrast material to use an iodinated substitute on additional imaging rather than administering steroids, according to a study published August 3 in Radiology.
A group led by Dr. Jennifer McDonald of the Mayo Clinic in Rochester, MN, compared the efficacy of substituting contrast in patients who had reacted to iodinated agents -- specifically using iohexol instead of iopromide -- to premedicating with steroids at 12 and two hours before imaging. Their study included 1,973 patients who underwent 4,360 iodine-based-contrast CT exams between June 2009 and May 2017; of these patients, 224 had 280 allergic reactions.
The group found a lower rate of repeat reactions in patients who were administered an iodinated contrast material substitute -- with or without contrast -- compared with patients who received steroid premedication and the same iodine-based contrast. The results included the following data points:
- Same iodinated contrast material and steroid premedication: 80 of 423 examinations (19%)
- Different iodinated contrast material and steroid premedication: five of 166 patients (3%)
- Different iodinated contrast material and no steroid premedication: 10 of 322 examinations (3%)
"In this cohort, using an iodinated contrast material (ICM) substitution was more effective for preventing repeat allergic-like reactions than using steroid premedication and the same ICM that caused the previous reaction," the group wrote.