Pharmacokinetics of enrofloxacin and danofloxacin in premature calves

Abstract

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.

Comparisons of plasma and fecal pharmacokinetics of danofloxacin and enrofloxacin in healthy and Mannheimia haemolytica infected calves

“…Furthermore, the PK parameters of danofloxacin were comparable with a recent study conducted in calves, except for the significantly lower half-life in our study 19 . It is worthwhile to mention that danofloxacin mainly undergoes hepatic elimination while enrofloxacin undergoes renal elimination 2 , and that danofloxacin has a relatively high bioavailability 30 . In addition, the difference in the disposition of these antibiotics could be attributed to their difference in octanyl:water and tissues:plasma partition coefficients, describing the lipophilicity of drug that affect absorption and distribution 31 – 33 .…”

Antimicrobial Resistance in Loggerhead Sea Turtles (Caretta caretta): A Comparison between Clinical and Commensal Bacterial Isolates

“…We tested two molecules of this class because it is well documented that the resistance against fluoroquinolones is closely related with the specific classes of molecules and the single molecule cannot mirror the entire category. Moreover, fluoroquinolones are one of the few therapeutic options for sea turtles [ 65 , 66 , 67 , 68 ].…”

“…We recorded about 40% of resistance in clinical isolates against Ciprofloxacin and Enrofloxacin, in contrast to the very low percentage found in the O/C isolates. Enrofloxacin is recommended for use in C. caretta for various infections such as conjunctivitis and lower respiratory diseases due to its long half-life and high bioavailability with low side effects [ 65 ]. Our study suggests that treatment with fluoroquinolones in loggerheads needs prior in vitro susceptibility testing, due to the increasing percentage of resistance found in clinical isolates of this species.…”

Pharmacokinetics and Pharmacokinetic/Pharmacodynamic Integration of Enrofloxacin Following Single Oral Administration of Different Doses in Brown Trout (Salmo trutta)

“…The plasma concentrations of enrofloxacin and ciprofloxacin were assayed according to the previously reported high-performance liquid chromatography–ultraviolet detection (HPLC–UV) method [ 19 ]. Briefly, the 200 μL of acetonitrile was added to a 100 μL of plasma sample followed vortexed for 45 s and centrifuged at 10,000× g for 12 min.…”