Toxicologic profile of iobitridol, a new nonionic low-osmolality contrast medium

Purpose: The toxicologic profile of iobitridol, a new nonionic low-osmolality contrast medium, was evaluated in compliance with the current regulatory requirements in Europe, the USA and Canada. Material and Methods: The toxicity of iobitridol was tested following acute or repeated i.v. administration in several different species (mouse, rat, dog); single oral administration in the mouse and intracisternal injection in the rat. Furthermore, teratogenicity and mutagenicity were evaluated in the rat and rabbit. Local perivenous toxicity was assessed in the rabbit. Results: The acute toxicity of iobitridol in the mouse is equivalent to that of iohexol, a reference product tested under the same conditions. Chronic administration (daily i.v. injection over 4 weeks) in the rat and dog did not demonstrate any particular toxicity for iobitridol. It should be noted that, unlike iohexol, iobitridol did not provoke any vacuolization of the renal tubular cells in the rat following repeated injections, Furthermore, this contrast agent did not show any teratogenic or mutagenic potential. The typical local inflammatory signs observed following perivenous injection in the rabbit were low in intensity and reversible. Conclusion: The toxicologic profile of iobitridol appears to be favorable and does not show any particular risk for clinical use under the usual indications of water-soluble iodinated contrast agents.