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Pharmacokinetics of enrofloxacin after intravenous, intramuscular and oral administration in houbara bustard ( Chlamydotis undulata macqueenii )
Author(s) -
Bailey T. A.,
Sheen R. S.,
Silvanose C.,
Samour J. H.,
Garner A.,
Harron D. W. G.
Publication year - 1998
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1046/j.1365-2885.1998.00143.x
Subject(s) - bustard , enrofloxacin , pharmacokinetics , medicine , veterinary medicine , biology , pharmacology , microbiology and biotechnology , antibiotics , ecology , ciprofloxacin , habitat
The in‐vitro activity of enrofloxacin against 117 strains of bacteria isolated from bustards was determined. Minimum inhibitory concentrations for 72% of the Proteus spp., E. coli , Salmonella spp. and Klebsiella spp. ( n = 61) and for 48% of the Streptococci spp. and Staphylococci spp. ( n = 31) were 0.5 μ g/mL. The minimum inhibitory concentration (MIC) of 76% of Pseudomonas spp. ( n = 25) was 2 μg/mL. Fourteen strains were resistant to concentrations 128 μg/mL. The elimination half‐lives ( t ½ elim β) (mean± SEM) of 10 mg/kg enrofloxacin in eight houbara bustards ( Chlamydotis undulata ) were 6.80± 0.79, 6.39± 1.49 and 5.63± 0.54 h after oral (p.o.), intramuscular (i.m.) and intravenous (i.v.) administration, respectively. Enrofloxacin was rapidly absorbed from the bustard gastro‐intestinal tract and maximum plasma concentrations of 1.84± 0.16 μg/mL were achieved after 0.66± 0.05 h. Maximum plasma concentration after i.m. administration of 10 mg/kg was 2.75± 0.11 μg/mL at 1.72± 0.19 h. Maximum plasma concentration after i.m. administration of 15 mg/kg in two birds was 4.86 μg/mL. Bioavailability was 97.3± 13.7% and 62.7± 11.1% after i.m. and oral administration, respectively. Plasma concentrations of enrofloxacin 0.5 μg/mL were maintained for at least 12 h for all routes at 10 mg/kg and for 24 h after i.m. administration at 15 mg/kg. Plasma enrofloxacin concentrations were monitored during the first 3 days of treatment in five houbara bustards and kori bustards ( Ardeotis kori ) with bacterial infections receiving a single daily i.m. injection of 10 mg/kg for 3 days. The mean plasma enrofloxacin concentrations in the clinical cases at 27 and 51 h (3.69 and 3.86 μg/mL) and at 48 h (0.70 μg/mL) were significantly higher compared with the 3 h and 24 h time intervals from clinically normal birds. The maximum plasma concentration ( C max )/MIC ratio was ranked i.v. (10/mg/kg) > i.m. (15 mg/kg) > i.m. (10 mg/kg) > oral (10 mg/kg), but it was only higher than 8:1 for i.v and i.m. administrations of enrofloxacin at 10 mg/kg and 15 mg/kg, respectively, against a low MIC (0.5 μg/mL). A dosage regimen of 10 mg/kg repeated every 12 h, or 15 mg/kg repeated every 24 h, would be expected to give blood concentrations above 0.5 μg/mL and hence provide therapeutic response in the bustard against a wide range of bacterial infections.