[Toxicity of iodixanol, a new nonionic iso-osmolar contrast medium, to rats by repeated intravenous administration for 4 weeks with a 4-week recovery period].

Groups of 10 male and 10 female Crl: CD (SD) BR rats were given iodixanol, a radiographic contrast medium, by intravenous injection at dosage levels of 30, 100 or 300 mgI/kg/day for four weeks to evaluate its toxicity. An extra 5 rats of each sex were given 300 mgI/kg/day for 4 weeks and then retained for 4 weeks without treatment to assess recovery. No clinical signs indicative of a toxic effect of iodixanol were noted. No effects of treatment with iodixanol on bodyweight gains, food consumption, laboratory investigations, ophthalmoscopic examinations, organ weights, bone marrow smears or macroscopic pathology were noted. Treatment related changes were noted microscopically in the kidneys only. Minimal cytoplasmic vacuolation in the proximal tubules was noted in a proportion of rats given 100 mgI/kg/day and all rats given 300 mgI/kg/day at the end of the treatment period. This effect was noted not to be fully reversible during four weeks off dose although recovery did occur in some rats.