Influences of tolfenamic acid and flunixin meglumine on the disposition kinetics of levofloxacin in sheep

Effect of Dexketoprofen on the Disposition Kinetics of Moxifloxacin in Plasma and Lung in Male and Female Rats

BACKGROUND

The simultaneous use of NSAIDs and antibiotics is recommended for bacterial diseases in human and veterinary medicine. Moxifloxacin (MFX) and dexketoprofen (DEX) can be used simultaneously in bacterial infections. However, there are no studies on how the simultaneous use of DEX affects the pharmacokinetics of MFX in rats.

OBJECTIVES

The aim of this study was to determine the effect of DEX on plasma and lung pharmacokinetics of MFX in male and female rats.

METHODS

A total of 132 rats were randomly divided into 2 groups: MFX (n=66, 33 males/33 females) and MFX+DEX (n=66, 33 females/33 males). MFX at a dose of 20 mg/kg and DEX at a dose of 25 mg/kg were administered intraperitoneally. Plasma and lung concentrations of MFX were determined using the highperformance liquid chromatography-UV and pharmacokinetic parameters were evaluated by noncompartmental analysis.

RESULTS

Simultaneous administration of DEX increased the plasma and lung area under the curve from 0 to 8 h (AUC0-8) and peak concentration (Cmax) of MFX in rats, while it significantly decreased the total body clearance (CL/F). When female and male rats were compared, significant differences were detected in AUC0-8, Cmax, CL/F and volume of distribution. The AUC0-8lung/AUC0-8plasma ratios of MFX were calculated as 1.68 and 1.65 in female rats and 5.15 and 4.90 in male rats after single and combined use, respectively.

CONCLUSION

MFX was highly transferred to the lung tissue and this passage was remarkably higher in male rats. However, DEX administration increased the plasma concentration of MFX in both male and female rats but did not change its passage to the lung. However, there is a need for a more detailed investigation of the difference in the pharmacokinetics of MFX in male and female rats.

Effect of ketoprofen on intravenous pharmacokinetics of ganciclovir in chukar partridges (Alectoris chukar)

The aim of the study was to determine the effect of ketoprofen (2 mg/kg) on the intravenous pharmacokinetics of ganciclovir (10 mg/kg) in chukar partridges (Alectoris chukar). Eight clinically healthy partridges were used in the study. The study was performed in two periods using a cross-over design following a 15-day drug washout period. Plasma concentrations of ganciclovir were determined using the high-pressure liquid chromatography-ultraviolet detector and analyzed by non-compartmental analysis. The elimination half-life (t_1/2ʎz ), area under the concentration-time curve (AUC_0-∞ ), total body clearance, and volume of distribution at steady state of ganciclovir were 1.63 h, 33.22 h*μg/ml, 0.30 L/h/kg, and 0.53 L/kg, respectively. Ketoprofen administration increased the t_1/2ʎz and AUC_0-∞ of ganciclovir by 78% and 108%, respectively, and while decreased Cl_T by 53%. The increased plasma concentration and prolonged elimination half-life of ganciclovir caused by ketoprofen may result in the prolonged duration of action and therapeutic effect of ganciclovir. However, the concomitant use requires determination of the pharmacokinetics of ketoprofen and the safety of both drugs.

Pharmacokinetic Behavior and Pharmacokinetic/Pharmacodynamic Integration of Danofloxacin Following Single or Co-Administration with Meloxicam in Healthy Lambs and Lambs with Respiratory Infections

The aim of this study was to determine the pharmacokinetics and pharmacodynamics of danofloxacin (DAN; 6 mg/kg) following subcutaneous administration alone or co-administration with meloxicam (MLX; 1 mg/kg) in healthy lambs and lambs with respiratory infections. The study was carried out using a total of four groups: HD (healthy; n = 6) and ID (infected; n = 7) groups who were administered DAN only, and HDM (healthy; n = 6) and IDM (infected; n = 7) groups who were administered DAN and MLX simultaneously. The plasma concentrations of DAN were determined using high-performance liquid chromatography–UV and analyzed by the non-compartmental method. DAN exhibited a similar elimination half-life in all groups, including both the healthy and infected lambs. The total clearance in the HDM, ID and IDM groups and volume of distribution in the HDM and IDM groups were significantly reduced. MLX in the IDM group significantly increased the area under the curve (AUC) and peak concentration (C_max) of DAN compared to the HD group. The Mannheimia haemolytica, Escherichia coli, and Streptococcus spp. strains were isolated from bronchoalveolar lavage fluid samples of the infected lambs. When co-administration with meloxicam, DAN at a 6 mg/kg dose can provide optimum values of ƒAUC_0–24/MIC (>56 h) and ƒC_max/MIC (>8) for susceptible M. haemolytica isolates with an MIC₉₀ value of 0.25 µg/mL and susceptible E. coli isolates with an MIC value of ≤0.125 µg/mL.

Pharmacokinetics of tulathromycin in pregnant ewes (Ovis aries) challenged with Campylobacter jejuni

The purpose of this study was to evaluate the pharmacokinetics of tulathromycin in the plasma and maternal and fetal tissues of pregnant ewes when administered within 24 hours of a single, IV Campylobacter jejuni (C. jejuni) challenge. Twelve, pregnant ewes between 72-92 days of gestation were challenged IV with C. jejuni IA3902 and then treated with 1.1 ml/45.36 kg of tulathromycin subcutaneously 18 hours post-challenge. Ewes were bled at predetermined time points and euthanized either at a predetermined time point or following the observation of vaginal bleeding or abortion. Following euthanasia, tissues were collected for bacterial culture, pharmacokinetics and histologic examination. The maximum (geometric) mean tulathromycin plasma concentration was estimated at 0.302 μg/mL, with a peak level observed at around 1.2 hours. The apparent systemic clearance of tulathromycin was estimated at 16.6 L/h (or 0.28 L/kg/h) with an elimination half-life estimated at approximately 22 hours. The mean tissue concentrations were highest in the uterus (2.464 μg/g) and placentome (0.484 μg/g), and were lowest in fetal liver (0.11 μg/g) and fetal lung (0.03 μg/g). Compared to previous reports, results of this study demonstrate that prior IV administration of C. jejuni appeared to substantially alter the pharmacokinetics of tulathromycin, reducing both the peak plasma concentrations and elimination half-life. However, additional controlled trials are required to confirm those observations.

Effect of ketoprofen and tolfenamic acid on intravenous pharmacokinetics of ceftriaxone in sheep

In this study, the pharmacokinetics of ceftriaxone (40 mg/kg) was determined following a single intravenous (IV) administration of ceftriaxone alone and co-administration with ketoprofen (3 mg/kg) or tolfenamic acid (2 mg/kg) in sheep. Eight healthy Akkaraman sheep (2.4 ± 0.3 years and 44 ± 4 kg of body weight) were used. The study was carried out according to the longitudinal design in three periods with a 15-day washout period between administrations. In the first period, sheep received ceftriaxone alone via an IV injection. In the second and third periods, the same sheep received ceftriaxone in combination with ketoprofen and tolfenamic acid, respectively. Plasma concentrations of ceftriaxone were assayed by high-performance liquid chromatography and analyzed using non-compartmental analysis. Following the administration of ceftriaxone alone, the elimination half-life (t_1/2ʎz ), area under the plasma concentration-time curve from zero (0) hours to infinity (∞) (AUC_0-∞ ), total clearance (Cl_T ), and volume of distribution at steady state were 1.42 h, 182.41 h*µg/ml, 0.22 L/h/kg, and 0.17 L/kg, respectively. While ketoprofen and tolfenamic acid significantly increased the t_1/2ʎz and AUC_0-∞ of ceftriaxone, they significantly reduced the Cl_T . Ceftriaxone (40 mg/kg, IV) in concurrent use with ketoprofen and tolfenamic acid can be administrated at the 12 h dosing intervals to maintain T> minimum inhibitory concentration (MIC) values above 60% in the treatment of infections caused by susceptible pathogens with the MIC value of ≤0.75 and ≤1 μg/mL, respectively, in sheep with an inflammatory condition.

Levofloxacin in veterinary medicine: a literature review

A potent third-generation antimicrobial fluoroquinolone drug, levofloxacin was introduced into human clinical practice in 1993. Levofloxacin is also used in veterinary medicine, however its use is limited: it is completely banned for veterinary use in the EU, and used extralabel in only companion animals in the USA. Since its introduction to clinical practice, many studies have been published on levofloxacin in animal species, including pharmacokinetic studies, tissue drug depletion, efficacy, and animal microbial isolate susceptibility to levofloxacin. This literature overview highlights the most clinically relevant and scientifically important levofloxacin studies linked to the field of veterinary medicine.

Effect of ketoprofen co-administration on pharmacokinetics of cefquinome following repeated administration in goats

The pharmacokinetics of cefquinome (2 mg/kg every 24 hr for 5 days) was determined following intramuscular administration alone and co-administration with ketoprofen (3 mg/kg every 24 hr for 5 days) in goats. Six goats were used for the study. In the study, the crossover pharmacokinetics design with 20-day washout period was performed in two periods. Plasma concentrations of cefquinome were assayed using high-performance liquid chromatography by ultraviolet detection. The mean terminal elimination half-life (t_1/2ʎz ), area under the concentration-time curve (AUC_0-24 ), peak concentration (C_max ), apparent volume of distribution (V_darea /F), and total body clearance (CL/F) of cefquinome after the administration alone were 4.85 hr, 11.06 hr*µg/ml, 2.37 µg/mL, 1.23 L/kg, and 0.17 L/h/kg after the first dose, and 5.88 hr, 17.01 hr*µg/mL, 3.04 µg/mL, 0.95 L/kg, and 0.11 L/h/kg after the last dose. Ketoprofen significantly prolonged t_1/2ʎz of cefquinome, increased AUC_0-24 and C_max , and decreased V_darea /F and CL/F. Cefquinome exhibited low accumulation after the administration alone and in combination with ketoprofen. These results indicated that ketoprofen prolonged the elimination of cefquinome in goats. The 24-hr dosing intervals at 2 mg/kg dose of cefquinome, which co-administered with ketoprofen, may maintain T> minimum inhibitory concentration (MIC) values above 40% in the treatment of infections caused by susceptible pathogens with the MIC value of ≤0.75 μg/ml in goats with an inflammatory condition.