title: Characterization of the pharmacokinetic disposition of levofloxacin in stallions after intravenous and intramuscular administration.
abstract: The target of the present study was to investigate the plasma disposition kinetics of levofloxacin in stallions (n = 6) following a single intravenous (i.v.) bolus or intramuscular (i.m.) injection at a dose rate of 4 mg/kg bwt, using a two-phase crossover design with 15 days as an interval period. Plasma samples were collected at appropriate times during a 48-h administration interval, and were analyzed using a microbiological assay method. The plasma levofloxacin disposition was best fitted to a two-compartment open model after i.v. dosing. The half-lives of distribution and elimination were 0.21 +/- 0.13 and 2.58 +/- 0.51 h, respectively. The volume of distribution at steady-state was 0.81 +/- 0.26 L/kg, the total body clearance (Cl(tot)) was 0.21 +/- 0.18 L/h/kg, and the areas under the concentration-time curves (AUCs) were 18.79 +/- 4.57 microg.h/mL. Following i.m. administration, the mean t(1/2el) and AUC values were 2.94 +/- 0.78 h and 17.21 +/- 4.36 microg.h/mL. The bioavailability was high (91.76% +/- 12.68%), with a peak plasma mean concentration (C(max)) of 2.85 +/- 0.89 microg/mL attained at 1.56 +/- 0.71 h (T(max)). The in vitro protein binding percentage was 27.84%. Calculation of efficacy predictors showed that levofloxacin might have a good therapeutic profile against Gram-negative and Gram-positive bacteria, with an MIC <or= 0.1 microg/mL.
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
authors.forename: A
authors.initials: A
authors.lastname: Goudah
authors.forename: K
authors.initials: K
authors.lastname: Abo El-Sooud
authors.forename: J-H
authors.initials: JH
authors.lastname: Shim
authors.forename: H-C
authors.initials: HC
authors.lastname: Shin
authors.forename: A M
authors.initials: AM
authors.lastname: Abd El-Aty
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D006207:Half-Life; D006736:Horses; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D064704:Levofloxacin; D008297:Male; D008657:Metabolic Clearance Rate; D015242:Ofloxacin / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D011485:Protein Binding
chemical_list: D000900:Anti-Bacterial Agents; D064704:Levofloxacin; D015242:Ofloxacin