Pharmacokinetics of Gadodiamide Injection in Patients with Moderately Impaired Renal Function

Objectives and Methods. The pharmacokinetic properties of gadodiamide injection were examined in 10 adult kidney-transplanted patients with stable or slowly deteriorating renal function. Total body clearance of gadodiamide and iothalamate and renal clearance of gadodiamide, iothalamate, and endogenous creatinine were compared to investigate whether gadodiamide injection has any influence on glomerular filtration and to evaluate the mechanism of excretion of gadodiamide in the kidneys. Results and Conclusions. The mean elimination half-life in these renally impaired patients was 5.8 hr, approximately five times longer than that observed in healthy adult volunteers. The volume of distribution of gadodiamide was found to be analogous to that seen in healthy volunteers, demonstrating that distribution of this agent is independent of renal function. Excretion of gadodiamide was delayed in these renally impaired patients, but the total fraction excreted in urine was analogous to that of healthy volunteers. After 5 days, the mean fraction excreted in feces was 0.4%, indicating minimal fecal elimination of gadodiamide, even in patients with impaired renal function.