DELAYED ADVERSE REACTIONS TO NONIONIC MONOMERIC CONTRAST-ENHANCED MEDIA

RATIONALE AND OBJECTIVES. A delayed adverse reaction is one occurring more than an hour after injection of contrast media. The frequency and symptoms of delayed adverse reaction to nonionic contrast media still are not well established. The purpose of the study is to clarify the frequency and symptoms of delayed adverse reactions using nonionic mon omeric contrast media. METHODS. Patients studied by computed tomograph y (CT) were the subject of the investigation. Delayed adverse reaction s were compared between the group receiving CT without contrast inject ion and the group receiving contrast injection.RESULTS. Delayed advers e reactions were noted in 293 of 2370 patients (12.4%) in the group wi th enhanced CT and in 93 of 907 patients (10.3%) in the group with une nhanced CT. The frequency of delayed adverse reaction to nonionic cont rast media was 2.1% (12.4% - 10.3%; P = 0.094). None of the risk facto rs were related with the incidence of delayed adverse reaction. The mo st common delayed adverse reaction was a mild skin reaction, which occ urred within 24 hours after injection of contrast media. CONCLUSIONs. The frequency of delayed adverse reaction to nonionic monomeric contra st media was 2.1%; the most common reactions were itching and limited urticaria.