Jh. Wible et al., NEUROTOXICITY OF NONIONIC X-RAY CONTRAST-MEDIA AFTER INTRACISTERNAL ADMINISTRATION IN RATS, European journal of radiology, 19(3), 1995, pp. 206-211
The neurotoxicity of an X-ray contrast medium appears inversely relate
d to the hydrophilicity of the agent. To further test this hypothesis,
four non-ionic X-ray contrast agents, differing in hydrophilicity, (i
oversol, iopromide, iohexol and iopamidol) were injected into the cist
ernal magna of ether-anesthetized rats. Iopromide demonstrated an acut
e median lethal dose of 122 mg I/kg. Other signs of toxicity included
convulsions, apnea, dyspnea and hypoactivity. In contrast, ioversol, i
ohexol and iopamidol caused no deaths when administered intracisternal
ly, up to a dose of 1000 mg I/kg. Animals treated with these nonionic
agents displayed signs of convulsions, apnea, dyspnea, chewing and hyp
oactivity. Iopromide possesses a hydrophilicity (e.g., water to octano
l partition coefficient) approximately 8.5 times smaller than ioversol
, 4.6 times smaller than iohexol and 2.3 times smaller than iopamidol.
These data support the hypothesis that tri-iodinated X-ray contrast m
aterials with smaller degrees of hydrophilicity produce greater toxici
ty to the central nervous system.