Ceftiofur pharmacokinetics in Nile tilapia Oreochromis niloticus after intracardiac and intramuscular administrations

PHARMACOKINETICS OF SINGLE INTRAMUSCULAR ADMINISTRATION OF CEFTIOFUR CRYSTALLINE FREE ACID IN AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS)

A pharmacokinetic study of ceftiofur crystalline free acid sterile oil suspension (CCFA) was performed in six apparently healthy juvenile American alligators (Alligator mississippiensis). A single intramuscular dose of 30 mg/kg was administered in the triceps muscle. Blood samples were collected prior to treatment and at 4, 12, 24, 48, 72, 120, 144, 192, 288, and 366 h post administration. Plasma samples were analyzed for ceftiofur equivalent concentrations using liquid chromatography-mass spectrometry. Pharmacokinetic parameters were determined by noncompartmental analysis. Mean peak plasma concentration was 23.2 µg/ml (range, 16.0-27.9), median time to maximum concentration was 72 h (range, 72-120), mean area under the curve from 0 to 366 h postdose was 4.24 h · mg/ml (range, 3.54-4.97), and mean terminal half-life was 143 h (range, 90.8-220). Plasma concentrations were maintained above the minimum inhibitory concentration for this study of 2.0 µg/ml, which was established from similar CCFA pharmacokinetic studies in other reptilian species, through the end of the data collection of 366 h. Because of prolonged plasma concentrations, a dosing interval could not be established in this study. Future studies should include extended collection time points and multidose studies to determine dosing regimens.

Pharmacokinetics of ceftiofur sodium in Peekapoo dogs following a single intravenous and subcutaneous injection

The present study aimed to determine the pharmacokinetic profiles of ceftiofur (as measured by ceftiofur and its active metabolites concentrations) in a small-size dog breed, Peekapoo, following a single intravenous or subcutaneous injection of ceftiofur sodium. The study population comprised of five clinically healthy Peekapoo dogs with an average body weight (BW) of 3.4 kg. Each dog received either intravenous or subcutaneous injection, both at 5 mg/kg BW (calculated as pure ceftiofur). Plasma samples were collected at different time points after the administration. Ceftiofur and its active metabolites were extracted from plasma samples, derivatized, and further quantified by high-performance liquid chromatography. The concentrations versus time data were subjected to noncompartmental analysis to obtain the pharmacokinetic parameters. The terminal half-life (t_{1/2 λz} ) was calculated as 7.40 ± 0.79 and 7.91 ± 1.53 hr following intravenous and subcutaneous injections, respectively. After intravenous treatment, the total body clearance (Cl) and volume of distribution at steady-state (V_SS ) were determined as 39.91 ± 4.04 ml hr^-1  kg^-1 and 345.71 ± 28.66 ml/kg, respectively. After subcutaneous injection, the peak concentration (C_max ; 10.50 ± 0.22 μg/ml) was observed at 3.2 ± 1.1 hr, and the absorption half-life (t_{1/2 ka} ) and absolute bioavailability (F) were calculated as 0.74 ± 0.23 hr and 91.70%±7.34%, respectively. The pharmacokinetic profiles of ceftiofur and its related metabolites demonstrated their quick and excellent absorption after subcutaneous administration, in addition to poor distribution and slow elimination in Peekapoo dogs. Based on the time of concentration above minimum inhibitory concentration (T > MIC) values calculated here, an intravenous or subcutaneous dose at 5 mg/kg of ceftiofur sodium once every 12 hr is predicted to be effective for treating canine bacteria with a MIC value of ≤4.0 μg/ml.

Pharmacokinetics of ceftiofur sodium in cats following a single intravenous and subcutaneous injection

Ceftiofur, a third-generation cephalosporin antibiotic, is being extensively used by pet doctors in China. In the current study, the detection method was developed for ceftiofur and its metabolites, desfuroylceftiofur (DCE) and desfuroylceftiofur conjugates (DCEC), in feline plasma. Then, the pharmacokinetics studies were performed following one single intravenous and subcutaneous injection of ceftiofur sodium in cats both at 5 mg/kg body weight (BW) (calculated as pure ceftiofur). Ceftiofur, DCE, and DCEC were extracted from plasma samples, then derivatized and further quantified by high-performance liquid chromatography. The concentrations versus time data were subjected to noncompartmental analysis to obtain the pharmacokinetics parameters. The terminal half-life (t_1/2λz ) was calculated as 11.29 ± 1.09 and 10.69 ± 1.31 hr following intravenous and subcutaneous injections, respectively. After intravenous treatment, the total body clearance (Cl) and volume of distribution at steady-state (V_SS ) were determined as 14.14 ± 1.09 ml hr^-1  kg^-1 and 241.71 ± 22.40 ml/kg, respectively. After subcutaneous injection, the peak concentration (C_max ; 14.99 ± 2.29 μg/ml) was observed at 4.17 ± 0.41 hr, and the absorption half-life (t_1/2ka ) and absolute bioavailability (F) were calculated as 2.83 ± 0.46 hr and 82.95%±9.59%, respectively. The pharmacokinetic profiles of ceftiofur sodium and its related metabolites demonstrated their relatively slow, however, good absorption after subcutaneous administration, poor distribution, and slow elimination in cats. Based on the time of drug concentration above the minimum inhibitory concentration (MIC) (T>MIC) calculated in the current study, an intravenous or subcutaneous dose at 5 mg/kg BW of ceftiofur sodium once daily is predicted to be effective for treating feline bacteria with a MIC value of ≤4.0 μg/ml.