Toxicological safety assessment of iomeprol, a new X-ray contrast agent.

The toxicology of pharmaceutical formulations of iomeprol, a new nonionic iodinated radiographic contrast agent, was studied in rodents (mice, rats and guinea-pigs) and non-rodents (rabbits and dogs). When injected intravascularly the acute toxicity of iomeprol, both in terms of median lethal dose and symptoms, was comparable to that of analogous triiodinated nonionic contrast media (CM). Intravenous daily dosing for 4 weeks showed that iomeprol was well tolerated at doses as high as the maximum dose anticipated for clinical use. Moreover, the compound did not possess reproductive, developmental, or genetic toxicity. Tissue tolerability was completely superimposable on those of reference CM such as iopamidol and iohexol. Finally, no antigenic potential was detected either in mice or guinea-pigs. These favourable toxicological characteristics bode well for iomeprol as an intravascular radiographic contrast agent.