Evaluating the Efficacy of Premedication in Preventing Hypersensitivity Reactions to Nonionic Contrast Agents.

Iodine-based contrast agents can induce various acute hypersensitivity reactions ranging from mild itching or vomiting shortly after administration to severe hypotension or loss of consciousness. In Japan, steroid premedication is commonly used to prevent acute hypersensitivity reactions. However, little clear evidence supporting its efficacy is available. In this study, we evaluated the effectiveness of premedication for acute hypersensitivity reactions induced by nonionic iodine contrast agents using propensity score matching. The participants included patients who were administered nonionic iodine contrast agents at Yokohama City Minato Red Cross Hospital between April 1, 2016 and March 31, 2022. Only first-time patients with no history of hypersensitivity reactions to contrast agents were included. The patients were classified into premedication and non-premedication groups, and the incidence proportions of acute hypersensitivity reactions were compared after matching. Of the 19976 patients, 422 (211 in each group) were matched. In the premedication group, 7 cases (3.32%) of hypersensitivity reactions occurred. In contrast, only 2 cases (0.95%) were observed in the non-premedication group. The odds ratio for the occurrence of hypersensitivity reactions in the premedication group was 3.500 (95% confidence interval, 0.727-16.848), with no significant difference. Therefore, premedication did not demonstrate the efficacy in preventing acute hypersensitivity reactions induced by nonionic iodine contrast agents. Based on the results of this study and guidelines, a recommendation for premedication was not reached for patients with a history of allergies, including asthma and atopy, as well as those with a history of drug or food allergies.