Comparative study of the dialysability of iobitridol and iohexol in the rat with impaired renal function

PURPOSE: To assess the dialysability of iobitridol, a comparative study with iohexol was conducted in the rat over 4 hours. MATERIAL AND METHODS: After ligature of the renal veins and arteries, a group of animals was submitted to continuous peritoneal dialysis, while the remainder were not. RESULTS: In the event of total renal failure, biliary excretion rose from 0.4 to 9% for iobitridol and from 2 to 16% for iohexol. In the rats submitted to peritoneal dialysis, biliary excretion decreased to 5% in the iobitridol group and to 13% in the iohexol group. Further, 18% of the test substances were eliminated in the dialysis liquid. CONCLUSIONS: As their physicochemical characteristics are very similar, the differences between the biliary excretion levels of these 2 media may be caused by a factor related to their respective molecular conformations.