A prospective randomised controlled trial to determine the early and late reactions after the use of iopamidol 340 (Niopam TM ) and iomeprol 350 (Iomeron ® ) in cardiac catheterisation

A new generation of intravascular contrast agents, the non-ionic monomers have safety profiles that are superior to those of older ionic compounds. There are, however, significant differences between these agents. Aim: The aim of this study was to determine the incidence of early ( 24 h to 7 days) reactions to two non-ionic contrast agents currently used during cardiac catheterisation: iopamidol 340 (Niopam TM Bracco UK Ltd.) and iomeprol 350 (Iomeron ® Bracco UK Ltd.). Methods: This was a prospective, randomised, double blinded trial. One thousand nine hundred and eighty-five patients undergoing cardiac catheterisation received one of the following contrast agents on a weekly basis: iopamidol 340 (Niopam TM ) and iomeprol 350 (Iomeron ® ). Reactions that were possibly related to the contrast agents were recorded on predefined data collection forms during the first 24 h of the procedure (early reaction) and after 24 h to 7 days (late reaction) by means of a questionnaire. Results: The baseline characteristics were matched in both the groups. There was no significant difference in the incidence of heat sensation experienced between the two groups (p = 0.1). Early non-heat reactions occurred in 2.7% of patients receiving iopamidol 340 (Niopam TM ) and 4% of those receiving iomeprol 350 (Iomeron ® )( p = 0.1). Significant electrocardiographic changes were recorded in 1.7% of patients who received iopamidol 340 (Niopam TM ), and 1% of those who received iomeprol 350 (Iomeron ® )( p = 0.2). Bradycardia occurred more frequently in the iopamidol 350 group (0.8%) compared to the iomeprol 350 group (0.1%) p = 0.02. Late reactions occurred in 16.2% of those receiving iopamidol 340 (Niopam TM ) and 21.7% of those receiving iomeprol 350 (Iomeron ® )( p = 0.02). A total of 23 (3.7%) patients in the iopamidol group and 39 (6.2%) patients in the iomeprol group reported nausea, p = 0.01. Conclusions: The incidence of early adverse reactions was similar with the two non-ionic contrast agents. Although bradycardia was slightly more frequent using iopamidol 340, nausea was reported more commonly 24 h after the procedure in patients receiving Iomeron 350 (Iomeron ® ). We conclude that there were only minor clinical differences between these agents; both are safe and well tolerated.