[Metabolic fate of 14C-isepamicin sulfate (14C-HAPA-B) in rats. II. Distribution and excretion after the successive administration].

Tissue concentrations of 14C-isepamicin (14C-HAPA-B) and its excretion were studied in male rats after 8- and 15-successive intramuscular administrations of 25 mg/kg/day. Plasma levels were hardly affected by the successive administration, and plasma concentrations as time patterns with 8- and 15-successive administrations were very similar to that with a single administration. Kidney levels of the drug increased remarkably by successive administrations. In all the organs tested except kidney, the elimination of the drug from the tissues tended to become somewhat slower with successive administrations but maximum concentrations were hardly affected by successive administrations. There was little difference between the excretion rates (urinary and fecal) after the successive doses and that after a single dose.