Early and late reactions after the use of iopamidol 340, ioxaglate 320, and iodixanol 320 in cardiac catheterization

Background Although modern contrast agents have tolerability superior to ol der agents, significant differences remain between the agents currently in use. Methods To investigate the incidence of early (<24 hours) and late (>24 hou rs to 7 days) reactions to 3 contrast agents commonly used in cardiac cathe terization, we performed a randomized, prospective, double-blind trial in w hich 2001 patients received one of the following agents. iopamidol 340, a n onionic monomer; ioxaglate 320, an ionic dimer; and iodixanol 320, a nonion ic dimer. Possible reactions to contrast were recorded during the hospital admission and after discharge by means of a questionnaire, telephone follow -up, or both. Results Early reactions occurred in 22.2% of those receiving ioxaglate, 7.6 % of those receiving iodixanol, and 8.8% of those receiving iopamidol (P < .0001). Late skin reactions occurred in 12.2% of those receiving iodixanol, 4.3% of those receiving ioxaglate, and 4.2% of those receiving iopamidol ( P < .0001). Conclusions The early side effect profile of certain ionic contrast agents suggests that these agents should no longer be used routinely in cardiac ca theterization. The use of nonionic agents, however, is associated with late skin reactions, but there are notable differences between the monomeric an d dimeric compounds. Although the skin reactions are generally benign, this is not always the case. Patients should be advised accordingly.