RESUMO
The purpose of this study was to assess the safety of gadoterate meglumine, a gadolinium-based contrast agent used in magnetic resonance imaging, in neonatal and juvenile rats. Rats received a single intravenous administration on postnatal day (PND) 10 or 6 administrations (from PND 10 to 30), at doses of 0, 0.6, 1.25, and 2.5 mmol/kg/administration, i.e. equivalent to approximately 1, 2 and 4-times the usual human dose. The animals were sacrificed at the end of the treatment period or after a 60-day treatment-free period. No mortality and no significant treatment-related effect on clinical signs, macroscopic and histopathological findings, development, behavior, sexual maturation and hematology parameters were observed. Minor non-adverse changes were observed in clinical biochemistry and urinary parameters. Based on AUC0-t, gadoterate meglumine was more rapidly eliminated at PND 30 vs. PND 10, reflecting maturation of kidney function. At the end of the treatment period, Gd was measurable in all organs sampled after single or repeated dosing and levels were dose-dependent as expected, the highest ones being found in kidneys. The total Gd concentrations were similar in all the organs following a single or repeated dosing. At the end of the treatment-free period, only traces of gadolinium were quantifiable, almost exclusively in kidneys, reflecting the excretory function of this organ. In conclusion, single or repeated administration of gadoterate meglumine to juvenile rats was well tolerated.
