Tissue levels of kanamycin in correlation with oto- and nephrotoxicity.

The time courses of kanamycin (KM) levels in the perilymph, kidney, liver, brain and blood were observed by a bioassay method in normal guinea pigs and in animals pretreated with KM for 10 successive days. In the kidney and perilymph of the normal guinea pigs, the injected KM became highly concentrated and was eliminated only after a protracted delay. This tendency was much more intensified in kidney and perilymph of the pretreated animals. By contrast, the KM in blood and brain was eliminated rapidly both in the normal and in the pretreated animals. It is concluded that the high accumulation and slow elimination of KM by the inner ear and kidney and, moreover, the enhancement of these phenomena by successive pretreatment are one of the important factors in the origin of oto- and nephrotoxicity.