The neural tolerance of the new non-ionic dimer
iodixanol was compared with that of the clinically used monomer
iohexol and the dimer
iotrolan. Behaviour of non-anaesthetised rabbits was monitored for 3 hours after intracisternal injection, at a dose-volume of 1 ml/kg of
iodixanol 150 mg I/ml,
iodixanol 320 mg I/ml,
iohexol 350 mg I/ml, or
iotrolan 300 mg I/ml (10 rabbits in each group).
Iotrolan induced
generalized seizures in 5 rabbits,
iodixanol 320 mg I/ml in 2 rabbits, and
iodixanol 150 mg I/ml in one rabbit. No excitative changes were observed in rabbits,
iodixanol 320 mg I/ml in 2 rabbits, and
iodixanol 150 mg I/ml in one rabbit. No excitative changes were observed in rabbits injected with
iohexol, but compared with the dimeric
contrast media the difference was not significant.
Iohexol produced significantly more severe depressive changes than
iodixanol 150 mg I/ml (p < 0.01),
iodixanol 320 mg I/ml (p < 0.05), and
iotrolan 300 mg I/ml (p < 0.05). The results indicate that the excitative neurotoxic potential of the dimer
iodixanol is likely to be lower than that of the clinically used dimer
iotrolan, but slightly higher than that of
iohexol. It may be expected that both dimers will produce a lower frequency of minor neurological adverse reactions than
iohexol.