Influences of dosage regimen and co-administration of low-molecular weight proteins and basic peptides on renal accumulation of arbekacin in mice

Objectives: The objectives of this study were to characterize renal accumulation of arbekacin, an aminoglycoside antibiotic for treatment of infections with methicillin-resistant Staphylococcus aureus, and to modulate renal uptake of arbekacin, leading to prevention of arbekacin-induced nephrotoxicity. Methods: In vivo renal uptake studies were performed using mice. Renal concentrations of arbekacin after a bolus intravenous administration at various doses were analysed by HPLC. In addition, renal concentrations were investigated 24 h after an injection of arbekacin alone or in combination with low-molecular weight proteins and basic peptides. Results: When administered by bolus injection at various doses, renal accumulation of arbekacin showed saturation kinetics with increasing dose. Renal concentration of arbekacin after a bolus administration remained constant from 4 to 24 h and subsequently decreased by a first-order process with a half-life of 42.7 h. The influences of three dosage regimens (a single injection of 4 mg/kg, two injections of 2 mg/kg and three injections of 1.33 mg/kg) were investigated. A single injection resulted in lower renal level of arbekacin than the multiple administrations. Co-administration of cytochrome c, lysozyme and N-WASP181-200 decreased renal accumulation of arbekacin in a dose-dependent manner. N-W(N1n), N-W(N1n,I2i,S3s) and N-W(N1n,K20k), in which the N-and/ or C-terminal regions of N-WASP181-200 were substituted by one to three D-isomers, more potently decreased renal arbekacin accumulation than N-WASP181-200. Conclusions: These data may be useful for prevention of arbekacin-induced nephrotoxicity owing to reduction of renal accumulation of the aminoglycoside.