Neural Tolerance of the Non-Ionic Dimers Iodixanol and Iotrolan and the Non-Ionic Monomer Iopamidol during Myelography in Non-Anaesthetised Rabbits

Abstract

and 2Department of Toxicology, Research and Development, Nycomed Imaging AS, Oslo, Norway. AbstractPurpose: The neural tolerance of the recently introduced dimer iodixanol (320 g Ill) was compared with that of the dimer iotrolan (300 g III) and of the monomer iopamidol (300 g Ill), both used in clinical myelography.Material and Methods: Non-anaesthetised rabbits were injected into the cisterna magna with Ringer's solution (control) or contrast media (CM) at doses of 1.0 or 0.5 ml/kg b.w. The behaviour of the animals (10 in each of 7 groups) was evaluated for signs of excitation and depression during the first 3 hours after injection.Results: At the dose level of 1.0 ml/kg b.w., iodixanol produced no seizures but did cause focal twitching in 4/10 rabbits. Iopamidol produced grand mal seizures in 2/10 and hyperexcitability in 4/10 rabbits. Iotrolan produced generalised grand mal seizures in 8/10 rabbits, an incidence of excitation significantly greater than that of iodixanol (p<O.OI) and iopamidol (p<0.05). The excitative effects of iodixanol were not significantly different from those of iopamidol and Ringer's solution. All 3 CM produced similar depressive effects on rabbit behaviour. Ringer's solution caused no depressive effects (p<O.Ol). A clear dose response was produced with all 3 CM after treatment with a lower dose of 0.5 ml/kg b.w. Conclusion:The results indicate that the neural tolerance in the rabbit of iodixanol is higher than that of iotrolan, and is at least equal to that of iopamidol.

Comparison in myelography between iodixanol 270 and 320 mgI/ml and iotrolan 300 mgI/ml: a multicentre, randomised, parallel-group, double-blind, phase III trial

“…Iodixanol 320 also has a slightly higher iodine concentration and viscosity than iotrolan 300, which might be important for image quality, especially in thoracic and cervical myelography after lumbar puncture. Improved tolerance to iodixanol compared with iotrolan has been shown in animal studies [13]. In the present study, efficacy and neural safety of iodixanol 270 and 320 mgI/ml are compared with those of iotrolan 300 mgI/ml during myelography in human adults.…”