Abstract

The study aims to establish the plasma pharmacokinetic parameters of levofloxacin in mixed-breed dogs, at a single dose of 5 mg/kg, intravenously, orally only and orally with sucralfate pre-treatment (1 g per animal), to evaluate its influence on antimicrobial absorption. Concentrations of levofloxacin in plasma were determined using high-performance liquid chromatography (HPLC) with fluorescence detection. After iv of levofloxacin, the mean (±SD) of AUC0–24, Vz, t½λz and MRT, was 19.05 ± 6.4 µg-h/ml, 2.43 ± 0.5 L/kg, 7.93 ± 1.41 hours and 8.7 ± 1.5 hours, respectively. After oral administration, the C max, t½λz and bioavailability were 1.95 ± 0.7 µg/ml, 7.65 ± 1.38 hours and 71.93 ± 9.75%, respectively. In animals given an oral dose of levofloxacin with sucralfate pre-treatment, there was a significant decrease (p < 0.05) in C max (0.57 ± 0.23 µg/ml), AUC (5.73 ± 2.26 µg-h/ml) and bioavailability (31.92 ± 14.19%). In the dogs studied, it is suggested that the dose 5 mg/kg of levofloxacin for both routes is inadequate to meet PK–PD targets for susceptible bacteria using breakpoints established by the Institute of Clinical and Laboratory Standards (CLSI).