Browsing by Author "Ider M."

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Inﬂuences of tolfenamic acid and ﬂunixin meglumine on the disposition kinetics of levoﬂoxacin in sheep
(2020-03-01) Corum D.D.; Corum O.; Yildiz R.; Faki H.E.; Ider M.; Cetin G.; Uney K.
The pharmacokinetics of levofloxacin (4 mg/kg), administered both alone and in combination with tolfenamic acid (2 mg/kg) and flunixin meglumine (2.2 mg/kg), was established after intravenous administration in sheep. Plasma levofloxacin concentrations were assayed by high-performance liquid chromatography and analysed according to the two-compartment open model. Following the administration of levofloxacin alone, the mean distribution half-life, elimination half-life, total clearance, volume of distribution at steady state and area under the plasma concentration-time curve were 0.20 h, 1.82 h, 0.39 L/h/kg, 0.96 L/kg and 10.40 h 3 mg/mL, respectively. Tolfenamic acid and ﬂunixin meglumine caused a slow elimination and increased plasma concentrations of levoﬂoxacin in combination administration. Levoﬂoxacin, with an alteration in the dosage regimen, can be used effectively with tolfenamic acid and ﬂunixin meglumine for the therapy of infections and inﬂammatory conditions in sheep.
Intravenous pharmacokinetics of moxifloxacin following simultaneous administration with flunixin meglumine or diclofenac in sheep
(2020-03-01) Altan F.; Corum O.; Yildiz R.; Eser Faki H.; Ider M.; Ok M.; Uney K.
In this study, the pharmacokinetics of moxifloxacin (5 mg/kg) was determined following a single intravenous administration of moxifloxacin alone and co-administration with diclofenac (2.5 mg/kg) or flunixin meglumine (2.2 mg/kg) in sheep. Six healthy Akkaraman sheep (2 ± 0.3 years and 53.5 ± 5 kg of body weight) were used. A longitudinal design with a 15-day washout period was used in three periods. In the first period, moxifloxacin was administered by an intravenous (IV) injection. In the second and third periods, moxifloxacin was co-administered with IV administration of diclofenac and flunixin meglumine, respectively. The plasma concentration of moxifloxacin was assayed by high-performance liquid chromatography. The pharmacokinetic parameters were calculated using a two-compartment open pharmacokinetic model. Following IV administration of moxifloxacin alone, the mean elimination half-life (t1/2β), total body clearance (ClT), volume of distribution at steady state (Vdss) and area under the curve (AUC) of moxifloxacin were 2.27 hr, 0.56 L h−1 kg−1, 1.66 L/kg and 8.91 hr*µg/ml, respectively. While diclofenac and flunixin meglumine significantly increased the t1/2β and AUC of moxifloxacin, they significantly reduced the ClT and Vdss. These results suggest that anti-inflammatory drugs could increase the therapeutic efficacy of moxifloxacin by altering its pharmacokinetics.
Pharmacokinetics and bioavailability of cefquinome and ceftriaxone in premature calves
(2019-11-01) Corum O.; Yildiz R.; Ider M.; Altan F.; Ok M.; Uney K.
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.
Pharmacokinetics of enrofloxacin and danofloxacin in premature calves
(2019-11-01) Corum O.; Altan F.; Yildiz R.; Ider M.; Ok M.; Uney K.
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.
Use of intestine-related biomarkers for detecting intestinal epithelial damage in neonatal calves with diarrhea
(2020-02-01) Ok M.; Yildiz R.; Hatipoglu F.; Baspinar N.; Ider M.; Üney K.; Ertürk A.; Durgut M.K.; Terzi F.
OBJECTIVE To evaluate the usefulness of intestinal biomarkers in determining the presence of intestinal epithelial damage in neonatal calves with diarrhea caused by 4 etiologic agents. ANIMALS 40 neonatal calves that were healthy (n = 10) or had diarrhea (30). PROCEDURES The study was a cross-sectional study. Results of hematologic analyses and serum concentrations of intestinal fatty acid–binding protein (I-FABP), liver fatty acid–binding protein (L-FABP), trefoil factor 3 (TFF-3), Claudin-3 (CLDN-3), γ-enteric smooth muscle actin (ACTG2), intestinal alkaline phosphatase (IAP), interleukin-8 (IL-8), platelet-activating factor (PAF), and leptin (LP) were compared among calves grouped according to whether they were healthy (control group; G-1) or had diarrhea caused by K99 Escherichia coli (G-2; n = 10), bovine rota-or coronavirus (G-3; 5 each), or Cryptosporidium spp (G-4; 10). RESULTS Across the 3 time points at which blood samples were obtained and evaluated, the groups of calves with diarrhea generally had markedly higher mean serum concentrations of L-FABP, TFF-3, IAP, IL-8, and LP, compared with the control group. In addition, G-2 also consistently had markedly higher mean serum concentrations of I-FAB and ACTG2 and lower mean serum concentrations of CLDN-3, compared with the control group. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that degree of intestinal epithelial damage differed among calves grouped by the etiologic agent of diarrhea and that such damage might have been more severe in calves with diarrhea caused by K99 E coli. Additionally, our results indicated that serum concentrations of I-FABP, L-FABP, TFF-3, IAP, IL-8, ACTG2, LP, and CLDN-3 were useful biomarkers of intestinal epithelial damage in calves of the present study.