T Ito1, I Yano, Y Hashimoto, K Inui. 1. Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Kyoto University, Japan.
Abstract
PURPOSE: The transepithelial transport of levofloxacin was evaluated in the isolated perfused kidney to investigate its renal secretory mechanisms. METHODS: Levofloxacin was instantaneously administered into the renal artery together with inulin and Evans blue-labeled albumin, and the single-pass dilution curves of the renal venous and urinary outflow were determined in the absence or presence of various compounds. Kinetic parameters were computed based on non-compartment moment analysis. RESULTS: The ratio of fractional excretion to filtration fraction (FE/FF) for levofloxacin was 2.99 +/- 0.18, indicating the involvement of tubular secretion. In the presence of cimetidine and quinolones, the FE/FF of levofloxacin was significantly decreased and the transepithelial mean transit time (Tcell) of levofloxacin was prolonged. The Tcell showed a negative correlation with renal secretion of levofloxacin, while the volume of distribution of levofloxacin showed no correlation. CONCLUSIONS: Transport on the brush-border membrane plays a determining step in the renal secretion of levofloxacin, and cimetidine and quinolones interact with levofloxacin transport on the brush-border membrane.
PURPOSE: The transepithelial transport of levofloxacin was evaluated in the isolated perfused kidney to investigate its renal secretory mechanisms. METHODS:Levofloxacin was instantaneously administered into the renal artery together with inulin and Evans blue-labeled albumin, and the single-pass dilution curves of the renal venous and urinary outflow were determined in the absence or presence of various compounds. Kinetic parameters were computed based on non-compartment moment analysis. RESULTS: The ratio of fractional excretion to filtration fraction (FE/FF) for levofloxacin was 2.99 +/- 0.18, indicating the involvement of tubular secretion. In the presence of cimetidine and quinolones, the FE/FF of levofloxacin was significantly decreased and the transepithelial mean transit time (Tcell) of levofloxacin was prolonged. The Tcell showed a negative correlation with renal secretion of levofloxacin, while the volume of distribution of levofloxacin showed no correlation. CONCLUSIONS: Transport on the brush-border membrane plays a determining step in the renal secretion of levofloxacin, and cimetidine and quinolones interact with levofloxacin transport on the brush-border membrane.
Authors: Larry A Bauer; Douglas J Black; Jennifer S Lill; Julie Garrison; Vidmantas A Raisys; Thomas M Hooton Journal: Antimicrob Agents Chemother Date: 2005-04 Impact factor: 5.191