The nephrotoxic potentials of the new aminoglycoside SCH 21420 and amikacin were compared in a rat model. Groups of rats received 100, 200, 300, or 600 mg of either drug per kg per day for 14 days. Enzymuria, urine osmolality, protein excretion, and blood urea nitrogen were monitored at periodic intervals, whereas creatinine clearance and pathological changes were determined at sacrifice. Amikacin caused more enzymuria at the two lower doses as well as greater proteinuria and blood urea nitrogen elevations at the highest dose than did SCH 21420 (P less than 0.05). Pathological changes were more severe with amikacin than with SCH 21420 at the three lower doses (P less than 0.05); however, at the 600 mg/kg per day dose, the pathological scores and creatinine clearances of animals receiving either drug were not significantly different (P greater than 0.05).
