Intravenous pharmacokinetics of ciprofloxacin in goats.

The pharmacokinetics of ciprofloxacin in goats was studied following intravenous administration. A single dose of 10 mg/kg was administered as an intravenous bolus, and serum samples were collected at predetermined intervals over a 24 h period. Ciprofloxacin levels were measured using high pressure liquid chromatography and the resulting concentration versus time curve was analyzed using a non linear regression analysis. The data were best represented by a two-compartment pharmacokinetic model with a mean elimination half-life of 2.72+/-1.04 h. Mean pharmacokinetic parameters obtained were area under the curve (AUC: 10.320+/-5.137 microg/ml per h), mean residence time (MRT: 3.334+/-1.428 h), apparent volume of distribution (Vdss: 3.373+/-0.893 l/kg) and total body drug clearance (tCl 19.596+/-9.059 ml/min per kg). Ciprofloxacin in goats showed the general pharmacokinetic characteristics of a typical fluoroquinolone antibacterial agent and we recommend a dose of 10 mg/kg to be administered intravenously at 12 h intervals to goats.

Comparative pharmacokinetics of enrofloxacin and ciprofloxacin in chickens.

The pharmacokinetics of enrofloxacin (EFX) and ciprofloxacin (CFX) was investigated in broiler chickens. Each antimicrobial was administered intravenously at a dose of 5 mg/kg body weight. Blood was taken in different preset times: prior and at 0.03, 0.06, 0.13, 0.25, 0.5, 1, 2, 4, 8, 12 and 24 h following drug administration. The concentrations of EFX and CFX in plasma were determined by high pressure liquid chromatography (HPLC). Plasma concentrations vs. time were analysed by a compartmental independent pharmacokinetic model that provided the most important kinetic parameters. Statistically significant differences between the two antimicrobials were found for most of the pharmacokinetic parameters: Area under the curve (AUC), area under first moment curve (AUMC), mean residence time (MRT), total body cleareance (ClB), volume of distribution beta (Vd beta) and volume of distribution at the steady state (Vd(ss)). Both antimicrobials were widely distributed in chickens throughout the body with a mean Vd(ss) of 1.98+/-0.18 L/kg for EFX, and 4.04+/-0.69 L/kg for CFX. The ClB for CFX was five times higher than that obtained for EFX. AUC, MRT and the diminished half time for EFX were two-four times higher than those obtained for CFX. These results indicate that CFX remains in the body for less time than the other quinolone. This characteristic of CFX suggests the advantage of a shorter withdrawal time for food producing animals treated with this antimicrobial.