Course of gentamicin nephrotoxicity

Metabolic balance and morphologic studies were performed on rats receiving gentamicin 100 mg/kg/day for a period of 8--10 days and during the recovery period. Daily urine flow rate increased with the administration of gentamiccin and remained elevated up to 20 days following the discontinuation of gentamicin, although BUN and plasma creatinine were virtually normal 10 days after the discontinuation of gentamicin. During the development of renal failure means daily electrolyte excretion remained normal. During the recovery period, however, sodium and potassium excretion exceeded control values while chloride and net acid excretion remained normal. Proteinuria developed during the administration of gentamicin and returned to normal 6--10 days after the discontinuation of gentamicin. Ten days of netilmicin administration (150 mg/kg/day) resulted in only mild tubular degeneration and no azotemia.