Pharmacokinetics of enrofloxacin and danofloxacin in premature calves.

The aim of this study was to determine the pharmacokinetics/pharmacodynamics of enrofloxacin (ENR) and danofloxacin (DNX) following intravenous (IV) and intramuscular (IM) administrations in premature calves. The study was performed on twenty-four calves that were determined to be premature by anamnesis and general clinical examination. Premature calves were randomly divided into four groups (six premature calves/group) according to a parallel pharmacokinetic (PK) design as follows: ENR-IV (10 mg/kg, IV), ENR-IM (10 mg/kg, IM), DNX-IV (8 mg/kg, IV), and DNX-IM (8 mg/kg, IM). Plasma samples were collected for the determination of tested drugs by high-pressure liquid chromatography with UV detector and analyzed by noncompartmental methods. Mean PK parameters of ENR and DNX following IV administration were as follows: elimination half-life (t1/2λz ) 11.16 and 17.47 hr, area under the plasma concentration-time curve (AUC0-48 ) 139.75 and 38.90 hr*µg/ml, and volume of distribution at steady-state 1.06 and 4.45 L/kg, respectively. Total body clearance of ENR and DNX was 0.07 and 0.18 L hr-1  kg-1 , respectively. The PK parameters of ENR and DNX following IM injection were t1/2λz 21.10 and 28.41 hr, AUC0-48 164.34 and 48.32 hr*µg/ml, respectively. The bioavailability (F) of ENR and DNX was determined to be 118% and 124%, respectively. The mean AUC0-48CPR /AUC0-48ENR ratio was 0.20 and 0.16 after IV and IM administration, respectively, in premature calves. The results showed that ENR (10 mg/kg) and DNX (8 mg/kg) following IV and IM administration produced sufficient plasma concentration for AUC0-24 /minimum inhibitory concentration (MIC) and maximum concentration (Cmax )/MIC ratios for susceptible bacteria, with the MIC90 of 0.5 and 0.03 μg/ml, respectively. These findings may be helpful in planning the dosage regimen for ENR and DNX, but there is a need for further study in naturally infected premature calves.

Corum O ，Altan F ，Yildiz R ，Ider M ，Ok M ，Uney K ... -  《-》

Pharmacokinetics and bioavailability of cefquinome and ceftriaxone in premature calves.

The aim of this study was to evaluate the pharmacokinetics and bioavailability of cefquinome (CFQ) and ceftriaxone (CTX) following intravenous (IV) and intramuscular (IM) administrations in premature calves. Using a parallel design, 24 premature calves were randomly divided into the two antibiotic groups. Each of the six animals in the first group received CFQ (2 mg/kg) through IV or IM administration. The second group received CTX (20 mg/kg) via the same administration route. Plasma concentrations of the drugs were analyzed by high-performance liquid chromatography and noncompartmental methods. Mean pharmacokinetic parameters of CFQ and CTX following IV administration were as follows: elimination half-life (t1/2λz ) 1.85 and 3.31 hr, area under the plasma concentration-time curve (AUC0-∞ ) 15.74 and 174 hr * μg/ml, volume of distribution at steady-state 0.37 and 0.45 L/kg, and total body clearance 0.13 and 0.12 L hr-1  kg-1 , respectively. Mean pharmacokinetic parameters of CFQ and CTX after IM injection were as follows: peak concentration 4.56 and 25.04 μg/ml, time to reach peak concentration 1 and 1.5 hr, t1/2λz 4.74 and 3.62 hr, and AUC0-∞ 22.75 and 147 hr * μg/ml, respectively. The bioavailability of CFQ and CTX after IM injection was 141% and 79%, respectively. IM administration of CFQ (2 mg/kg) and CTX (20 mg/kg) can be recommended at 12-hr interval for treating infections caused by susceptible bacteria, with minimum inhibitory concentration values of ≤0.5 and ≤4 μg/ml, respectively, in premature calves. However, further research is indicated to assess the pharmacokinetic parameters following multiple doses of the drug in premature calves.

Corum O ，Yildiz R ，Ider M ，Altan F ，Ok M ，Uney K ... -  《-》

Pharmacokinetics of enrofloxacin following intravenous and intramuscular administration in Angora rabbits.

Elmas M ，Uney K ，Yazar E ，Karabacak A ，Traş B ... -  《RESEARCH IN VETERINARY SCIENCE》

Implications for dosing regimen of enrofloxacin administered concurrently with dexamethasone in febrile buffalo calves.

Sidhu PK ，Ramalingam B ，Kaur G ，Rampal S ，Coetzee JF ... -  《-》

Pharmacokinetic and pharmacodynamic properties of enrofloxacin in southern crested caracaras (Caracara plancus).

Waxman S ，Prados AP ，de Lucas J ，San Andres MI ，Sassaroli JC ，Orozco M ，Argibay H ，Rodriguez C ... -  《JOURNAL OF AVIAN MEDICINE AND SURGERY》