FREQUENCY OF LATE ALLERGY-LIKE ADVERSE REACTIONS FOLLOWING INJECTION OF INTRAVASCULAR NONIONIC CONTRAST-MEDIA - A RETROSPECTIVE STUDY COMPARING A NONIONIC MONOMERIC CONTRAST-MEDIUM WITH A NONIONIC DIMERIC CONTRAST-MEDIUM

Purpose: A retrospective study was undertaken of the late adverse reac tions following the injection of contrast media. The purpose was to de termine whether there was a difference between non-ionic monomeric (io hexol) and non-ionic dimeric (iodixanol) contrast media in the reactio ns produced. Material and Methods: A total of 3408 patients were sent a written questionnaire in which they were asked to confirm or deny an y subjective discomfort or adverse event during a period of one hour t o one week after a previous radiological examination with contrast med ium. Patients who had undergone angiography (i.v. or i.a. injection) a nd CT (i.v. injection) were included. Objective signs of an allergy-li ke reaction were listed and the patients were asked to subjectively qu antify any consequent discomfort. Results. The compliance rate was 84% . Of the 3075 injections finally included in the study, 133 (4.3%) had resulted in contrast-medium-related adverse reactions of which 72 (2. 3%) were immediate and 61 (2%) were late. Iohexol induced late reactio ns in 14/851 (1.7%) cases, and iodixanol in 24/1218 (2.0%) cases follo wing i.v. injection and in 23/1006 (2.3%) cases following i.a. injecti on. The differences were not significant. There were no differences be tween the two contrast media in the subjective rating of discomfort ex cept that the patients who had received iodixanol also had the highest individual-intensity score. No patient had been hospitalized owing to an adverse reaction and all reactions had been regarded as mild or mo derate. Conclusion. The number of late adverse reactions was low. Ther e was no difference in the frequency of the late adverse reactions fol lowing i.v. injection between iodixanol and iohexol. There was also no difference in the reactions between the i.a. and i.v. injections of i odixanol.