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1.
The purpose of this study was to establish the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in the plasma and interstitial fluid (ISF) following subcutaneous (s.c.) administration of enrofloxacin. Ultrafiltration probes were placed in the s.c. tissue, gluteal musculature, and pleural space of five calves. Each calf received 12.5 mg/kg of enrofloxacin. Plasma and ISF samples were collected for 48 h after drug administration and analyzed by high pressure liquid chromatography. Plasma protein binding of enrofloxacin and ciprofloxacin was measured using a microcentrifugation system. Tissue probes were well tolerated and reliably produced fluid from each site. The mean +/- SD plasma half-life was 6.8 +/- 1.2 and 7.3 +/- 1 h for enrofloxacin and ciprofloxacin, respectively. The combined (ciprofloxacin + enrofloxacin) peak plasma concentration (Cmax) was 1.52 microg/mL, and the combined area under the curve (AUC) was 25.33 microg/mL. The plasma free drug concentrations were 54% and 81% for enrofloxacin and ciprofloxacin, respectively, and free drug concentration in the tissue fluid was higher than in plasma. We concluded that Cmax/MIC and AUC/MIC ratios for free drug concentrations in plasma and ISF would meet suggested ratios for a targeted MIC of 0.06 microg/mL.  相似文献   

2.
Antibiotic distribution to interstitial fluid (ISF) and pulmonary epithelial fluid (PELF) was measured and compared to plasma drug concentrations in eight healthy calves. Enrofloxacin (Baytril® 100) was administered at a dose of 12.5 mg/kg subcutaneously (SC), and tilmicosin (Micotil® 300) was administered at a dose of 20 mg/kg SC. PELF, sampled by two different methods—bronchoalveolar lavage (BAL) and direct sampling (DS)—plasma, and ISF were collected from each calf and measured for tilmicosin, enrofloxacin and its metabolite ciprofloxacin by HPLC. Pharmacokinetic analysis was performed on the concentrations in each fluid, for each drug. The enrofloxacin/ciprofloxacin concentration as measured by AUC in DS samples was 137 ± 72% higher than in plasma, but in BAL samples, this value was 535 ± 403% (p < .05). The concentrations of tilmicosin in DS and BAL samples exceeded plasma drug concentrations by 567 ± 189% and 776 ± 1138%, respectively. The enrofloxacin/ciprofloxacin concentrations collected by DS were significantly different than those collected by BAL, but the tilmicosin concentrations were not significantly different between the two methods. Concentrations of enrofloxacin/ciprofloxacin exceeded the MIC values for bovine respiratory disease pathogens but tilmicosin did not reach MIC levels for these pathogens in any fluids.  相似文献   

3.
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4.
Plasma, urine, and skin drug concentrations were determined for dogs (n=12) given five daily oral doses of marbofloxacin (MAR) (2.75 mg/kg), enrofloxacin (ENR) (5.0 mg/kg) or difloxacin (DIF) (5.0 mg/kg). Concentrations of the active metabolite of ENR, ciprofloxacin (CIP), were also determined. The three-period, three-treatment crossover experimental design included a 21-day washout period between treatments. Area under the plasma drug concentration vs. time curve (AUC0-last, microg/mLxh of MAR was greater than for ENR, CIP, ENR/CIP combined, and DIF. Maximum concentration (Cmax) of MAR was greater than ENR, CIP, and DIF. Time of maximum plasma concentration (Tmax) was similar for MAR and DIF; Tmax occurred earlier for ENR and later for CIP. Plasma half-life (t1/2) of MAR was longer than for ENR, CIP, and DIF. Urine concentrations of DIF were less than MAR or ENR/CIP combined, but urine concentrations of MAR and ENR/CIP combined did not differ. DIF skin concentrations were less than the concentrations of MAR or ENR/CIP combined 2 h after dosing, but skin concentrations of MAR and ENR/CIP combined did not differ.  相似文献   

5.
The intramuscular (IM) and oral (PO) disposition of enrofloxacin, a new fluoroquinolone antimicrobial drug, were evaluated in African grey parrots. Peak enrofloxacin concentration, mean (+/- SEM), at 1 h following a 15-mg/kg IM dose was 3.87 (+/- 0.27) micrograms/ml and declined with a mean residence time of 3.05 h. Peak enrofloxacin plasma concentrations at 2 to 4 h following oral doses of 3, 15, and 30 mg/kg were 0.31 (+/- 0.11), 1.12 (+/- 0.11), and 1.69 (+/- 0.23) micrograms/ml, respectively, and declined with a mean residence time of 3.44-5.28 h. The relative bioavailability of the 15-mg/kg oral dose was 48%. An equipotent metabolite, ciprofloxacin, was detected in plasma at concentrations ranging from 3 to 78% of those of enrofloxacin. Enrofloxacin concentrations and area under the curve were significantly lower, the mean residence time significantly shorter and the ciprofloxacin/enrofloxacin ratios higher, following 10 days of oral treatment at 30 mg/kg every 12 h. Following 10 days of treatment, no significant biochemical changes were noted; however, polydipsia and polyuria occurred in treated birds, but resolved quickly upon discontinuation of enrofloxacin administration. These studies indicate that a rational starting dose for enrofloxacin in psittacines (7.5-30 mg/kg BID) should be higher than those in other domestic animals.  相似文献   

6.
The objective of this study was to determine the pharmacokinetics (PK) of enrofloxacin in pigs and compare to the tissue interstitial fluid (ISF). Six healthy, young pigs were administered 7.5 mg/kg enrofloxacin subcutaneously (SC). Blood and ISF samples were collected from preplaced intravenous catheters and ultrafiltration sampling probes placed in three different tissue sites (intramuscular, subcutaneous, and intrapleural). Enrofloxacin concentrations were measured using high-pressure liquid chromatography with fluorescence detection, PK parameters were analyzed using a one-compartment model, and protein binding was determined using a microcentrifugation system. Concentrations of the active metabolite ciprofloxacin were negligible. The mean ± SD enrofloxacin plasma half-life, volume of distribution, clearance, and peak concentration were 26.6 ± 6.2 h (harmonic mean), 6.4 ± 1.2 L/kg, 0.18 ± 0.08 L/kg/h, and 1.1 ± 0.3 μg/mL, respectively. The half-life of enrofloxacin from the tissues was 23.6 h, and the maximum concentration was 1.26 μg/mL. Tissue penetration, as measured by a ratio of area-under-the-curve (AUC), was 139% (± 69%). Plasma protein binding was 31.1% and 37.13% for high and low concentrations, respectively. This study demonstrated that the concentration of biologically active enrofloxacin in tissues exceeds the concentration predicted by the unbound fraction of enrofloxacin in pig plasma. At a dose of 7.5 mg/kg SC, the high tissue concentrations and long half-life produce an AUC/MIC ratio sufficient for the pathogens that cause respiratory infections in pigs.  相似文献   

7.
Intorre, L., Mengozzi, G., Bertini, S., Bagliacca, M., Luchetti, E. and Soldani, G., 1997. The plasma kinetics and tissue distribution of enrofloxacin and its metabolite ciprofloxacin in the Muscovy duck. Veterinary Research Communications, 21 (2), 127-136The disposition and tissue distribution of enrofloxacin and of its main metabolite ciprofloxacin were investigated in ducks after oral or intramuscular administration of a single dose of 10 mg/kg enrofloxacin. Plasma and tissue concentrations were determined by a HPLC method. The peak concentrations of enrofloxacin after intramuscular administration (1.67 µg/ml at 0.9 h) were higher than after an oral dose (0.99 µg/ml at 1.38 h). The relative bioavailability of enrofloxacin after administration directly into the crop was 68%, while the metabolic conversion of enrofloxacin to ciprofloxacin was quite low (<10%) with both routes of administration. High tissue concentrations and high tissue:plasma concentration ratios were demonstrated for enrofloxacin and ciprofloxacin 24 h after treatment. It was concluded that a dose of 10 mg/kg per day provides serum and tissue concentrations sufficiently high to be effective in the control of many infectious diseases of ducks.  相似文献   

8.

  1. The pharmacokinetics of enrofloxacin and marbofloxacin was studied in Japanese quails and common pheasants. Healthy mature birds from both species and both genders were treated intravenously and orally with enrofloxacin (10 mg/kg) and marbofloxacin (5 mg/kg).

  2. After intravenous administration enrofloxacin was extensively metabolised to ciprofloxacin. Metabolites of marbofloxacin were not detected. Values of volume of distribution were respectively 4.63 l/kg and 3.67 l/kg for enrofloxacin and 1.56 l/kg and 1.43 l/kg for marbofloxacin. In quails, total body clearance values were higher than those in pheasants and other avian species.

  3. After oral application enrofloxacin was rapidly absorbed in quails, more rapidly than marbofloxacin. Pheasants absorbed both antimicrobials at a lower rate. Higher bioavailability was observed for marbofloxacin (118%). Relatively low bioavailability was established in quails for enrofloxacin (26.4%), accompanied by extensive conversion to ciprofloxacin.

  4. Generally, quails absorbed and eliminated both fluoroquinolones more rapidly than pheasants; the latter showed pharmacokinetics similar to poultry. Because of favourable pharmacokinetic properties, marbofloxacin should be preferred for oral administration in Japanese quails and pheasants for treatment of infections caused by equally susceptible pathogens.

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9.
Griffith, J.E., Higgins, D.P., Li, K.M., Krockenberger, M.B., Govendir, M. Absorption of enrofloxacin and marbofloxacin after oral and subcutaneous administration in diseased koalas (Phascolarctos cinereus). J. vet. Pharmacol. Therap. 33 , 595–604. Koalas (n = 43) were treated daily for up to 8 weeks with enrofloxacin: 10 mg/kg subcutaneously (s.c.), 5 mg/kg s.c., or 20 mg/kg per os (p.o.); or marbofloxacin: 1.0–3.3 mg/kg p.o., 10 mg/kg p.o. or 5 mg/kg s.c. Serial plasma drug concentrations were determined on day 1 and again at approximately 2 weeks, by liquid chromatography. The median (range) plasma maximum concentrations (Cmax) for enrofloxacin 5 mg/kg s.c. and 10 mg/kg s.c. were 0.83 (0.68–1.52) and 2.08 (1.34–2.96) μg/mL and the median (range) Tmax were 1.5 h (1–2) and 1 h (1–2) respectively. Plasma concentrations of orally dosed marbofloxacin were too low to be quantified. Oral administration of enrofloxacin suggested absorption rate limited disposition pharmacokinetics; the median (range) Cmax for enrofloxacin 20 mg/kg p.o. was 0.94 (0.76–1.0) μg/mL and the median (range) Tmax was 4 h (2–8). Oral absorption of both drugs was poor. Plasma protein binding for enrofloxacin was 55.4 ± 1.9% and marbofloxacin 49.5 ± 5.3%. Elevations in creatinine kinase activity were associated with drug injections. Enrofloxacin and marbofloxacin administered at these dosage and routes are unlikely to inhibit the growth of chlamydial pathogens in vivo.  相似文献   

10.
The purpose of this study was to determine the concentration of enrofloxacin and its active metabolite, ciprofloxacin, in alveolar macrophages (AM) and epithelial lining fluid (ELF) of the lungs in comparison to plasma concentrations in healthy dogs. Eleven dogs were given a single oral dose (5 mg/kg) of enrofloxacin. Four hours later, plasma and bronchoalveolar lavage (BAL) fluid were collected. Cells were separated from the BAL fluid and lysed for determination of drug concentrations within AM. Supernatant was used to determine concentrations of drugs in ELF. Drug assays were performed by high-performance liquid chromatography.
  The concentration of enrofloxacin (mean ± SD) was 0.33 ± 0.14 μg/mL in plasma, 3.34 ± 2.4 μg/mL in AM and 4.79 ± 5.0 μg/mL in ELF. The concentration of ciprofloxacin was 0.42 ± 0.26 μg/mL in plasma, 1.15 ± 1.03 μg/mL in AM and 0.26 ± 0.26 μg/mL in ELF. Mean concentrations of both drugs in AM were greater than in plasma (AM to plasma ratio, 10.3 for enrofloxacin and 4.7 for ciprofloxacin). Mean concentrations of enrofloxacin, but not ciprofloxacin, in ELF were greater than in plasma (ELF to plasma ratio, 13.5 for enrofloxacin and 0.52 for ciprofloxacin). Enrofloxacin concentrations in AM and ELF largely exceeded the MICs of the major bacterial pathogens and surpassed by about two times the breakpoint MIC of that drug, and ciprofloxacin concentrations in AM surpassed the MIC of many susceptible organisms. These results suggest that sufficient antimicrobial activity is present in AM and ELF of dogs following oral administration of enrofloxacin to be effective in the treatment of lower respiratory tract infections involving susceptible organisms.  相似文献   

11.
Enrofloxacin and marbofloxacin are two veterinary fluoroquinolones used to treat severe bacterial infections in horses. A repeated measures study has been designed to compare their pharmacokinetic parameters, to investigate their bioavailability and to estimate their absorbed fraction and first-pass effect by using plasma, urinary and metabolite data collected from five healthy mares. Clearance and V(d(ss)) were greater for enrofloxacin (mean +/- SD = 6.34 +/- 1.5 mL/min/kg and 2.32 +/- 0.32 L/kg, respectively) than for marbofloxacin (4.62 +/- 0.67 mL/min/kg and 1.6 +/- 0.25 L/kg, respectively). Variance of the AUC(0-inf) of marbofloxacin was lower than that for enrofloxacin, with, respectively, a CV = 15% and 26% intravenously and a CV = 31% and 55% after oral administration. Mean oral bioavailability was not significantly different between marbofloxacin (59%) and enrofloxacin (55%). The mean percentage of the dose eliminated unchanged in urine was significantly higher for marbofloxacin (39.7%) than that for enrofloxacin (3.4%). Absorbed fraction and first-pass effect were only determinable for enrofloxacin, whereas the percentage of the dose absorbed in the portal circulation was estimated to be 78% and the fraction not extracted during the first pass through the liver was 65%. Consequently, the moderate observed bioavailability of enrofloxacin appears to be mainly caused by hepatic first-pass effect.  相似文献   

12.
BACKGROUND: Fluoroquinolones are often used interchangeably in dogs and cats. HYPOTHESIS: Predicted therapeutic efficacy differs among fluoroquinolones. ANIMALS: Bacterial pathogens isolated from dogs and cats. METHODS: Using microtube-dilution procedures, percent resistance and 2 pharmacodynamic/pharmacokinetic indices (maximum concentration/minimum inhibitory concentration [Cmax/MIC] [target 0.10] and area under curve/minimum inhibitory concentration [AUC/MIC] [target 0.125]) were compared prospectively at low and high doses (mg/kg) for ciprofloxacin (5 and 20), difloxacin (5 and 10), enrofloxacin (including enrofloxacin+ciprofloxacin) (5 and 20), marbofloxacin (2.5 and 5), and orbifloxacin (2.5 and 7.5). Indices were calculated for organisms represented by < or = 15 isolates. RESULTS: Percent resistance for all Gram-negative (n = 180; 20+/-3%; 39+/-5% for Escherichia coli) and Gram-positive isolates (n = 66; 18+/-3%) did not differ among drugs or organisms. The pattern of Cmax/MIC was generally enrofloxacin+ciprofloxacin > or = enrofloxacin or ciprofloxacin > or = marbofloxacin > or = orbifloxacin > or = difloxacin; and for AUIC/ MIC, enrofloxacin+ciprofloxacin > or = marbofloxacin > or = ciprofloxacin > or = enrofloxacin > difloxacin > orbifloxacin. Among susceptible Gram-negative isolates studied (n = 117), targeted Cmax/MIC or AUC/MIC were achieved in 88% of E. coli, 53% of Proteus mirabilis, and 35% of Pseudomonas aeruginosa; and for susceptible Gram-positive isolates studied (n = 49), 53% of Streptotoccus spp. and Staphylococcus intermedius and 27% of Staphylococcus spp. At the high dose, the proportion of isolates for which a target was reached was: ciprofloxacin, enrofloxacin+ciprofloaxin, and marbofloxacin (77%), enrofloxacin (73%), orbifloxacin (51%), and difloxacin (40%); and at the low dose, enrofloxacin+ciprofloxacin and enrofloxacin (43%), ciprofloxacin (40%), marbofloxacin (39%), orbifloxacin (29%), and difloxacin (28%). CONCLUSIONS: E. coli resistance to fluoroquinolones approximated 40%. For susceptible isolates, enrofloxacin, marbofloxacin, and ciprofloxacin more consistently reached indices associated with predicted efficacy, but only at the high dose.  相似文献   

13.
The pharmacokinetics of enrofloxacin administered orally and i.v. to American alligators (Alligator mississippiensis) at 5 mg/kg was determined. Plasma levels of enrofloxacin and its metabolite ciprofloxacin were measured using high-performance liquid chromatography and the resulting concentration versus time curve analyzed using compartmental modeling techniques for the i.v. data and noncompartmental modeling techniques for the oral data. A two-compartment model best represented the i.v. data. Intravenous administration of enrofloxacin resulted in an extrapolated mean plasma concentration of 4.19 +/- 4.23 microg/ml at time zero, with average plasma drug levels remaining above 1.0 microg/ml for an average of 36 hr. Plasma volume of distribution for i.v. enrofloxacin was 1.88 +/- 0.96 L/kg, with a harmonic mean elimination half-life of 21.05 hr and mean total body clearance rate of 0.047 +/- 0.021 L/hr/kg. Plasma levels of p.o. enrofloxacin remained below 1.0 microg/ml in all test animals, and average concentrations ranged from 0.08 to 0.50 microg/ml throughout the sampling period. Oral administration of enrofloxacin achieved a mean maximum plasma concentration of 0.50 +/- 0.27 microg/ml at 55 +/- 29 hr after administration, with a harmonic mean terminal elimination half-life of 77.73 hr. Minimal levels of ciprofloxacin were detected after both oral and i.v. enrofloxacin administration, with concentrations below minimum inhibitory concentrations for most susceptible organisms. On the basis of the results of this study, enrofloxacin administered to American alligators at 5 mg/kg i.v. q 36 hr is expected to maintain plasma concentrations that approximate the minimum inhibitory concentration for susceptible organisms (0.5 microg/ml). Enrofloxacin administered to American alligators at 5 mg/kg p.o. is not expected to achieve minimum inhibitory values for susceptible organisms.  相似文献   

14.
The pharmacokinetics after oral application of the fluoroquinolones (FQs), enrofloxacin, difloxacin, marbofloxacin and orbifloxacin were compared in independent crossover studies in Beagle dogs. Commercially available tablet formulations were given at common dosage recommended by the manufacturers which were 2.0 mg/kg body weight (bw) for marbofloxacin, 2.5 mg/kg bw for orbifloxacin and 5.0 mg/kg bw for enrofloxacin and difloxacin. Analysis was performed by an agar diffusion assay. Pharmacokinetic parameters were calculated by noncompartmental methods. All FQs were rapidly absorbed and achieved average peak serum concentrations of 1.41, 1.11, 1.47 and 1.37 mug/mL for enrofloxacin, difloxacin, marbofloxacin and orbifloxacin, respectively. Enrofloxacin was eliminated at a terminal half-life (t(1/2)) of 4.1 h, difloxacin at 6.9 h, orbifloxacin at 7.1 h and marbofloxacin at 9.1 h. While the area under the serum concentration-time curve of the 24-h dosing interval (AUC0--24) for marbofloxacin and orbifloxacin were similar (approximately 13 microg x h/mL), enrofloxacin attained an AUC(0-24) of 8.7 and difloxacin of 9.3 microg x h/mL. Because of its favourable pharmacokinetics combined with excellent in vitro activity, enrofloxacin exhibited superior pharmacodynamic predictors of in vivo antimicrobial activity as C(max)/MIC (maximum serum concentration/minimum inhibitory concentration) and AUC(0-24)/MIC (area under the 24-h serum concentration--time curve/minimum inhibitory concentration) compared with other FQs.  相似文献   

15.
The plasma pharmacokinetics of danofloxacin and enrofloxacin in broiler chickens was investigated following single intravenous (i.v.) or oral administration (p.o.) and the steady-state plasma and tissue concentrations of both drugs were investigated after continuous administration via the drinking water. The following dosages approved for the treatment of chickens were used: danofloxacin 5 mg/kg and enrofloxacin 10 mg/kg of body weight. Concentrations of danofloxacin and enrofloxacin including its metabolite ciprofloxacin were determined in plasma and eight tissues by specific and sensitive high performance liquid chromatography methods. Pharmacokinetic parameter values for both application routes calculated by noncompartmental methods were similar for danofloxacin compared to enrofloxacin with respect to elimination half-life (t1/2: approximately 6-7 h), mean residence time (MRT; 6-9 h) and mean absorption time (MAT; 1.44 vs. 1.20 h). However, values were twofold higher for body clearance (ClB; 24 vs. 10 mL/min. kg) and volume of distribution at steady state (VdSS; 10 vs. 4 L/kg). Maximum plasma concentration (Cmax) after oral administration was 0.5 and 1.9 micrograms/mL for danofloxacin and enrofloxacin, respectively, occurring at 1.5 h for both drugs. Bioavailability (F) was high: 99% for danofloxacin and 89% for enrofloxacin. Steady-state plasma concentrations (mean +/- SD) following administration via the drinking water were fourfold higher for enrofloxacin (0.52 +/- 0.16 microgram/mL) compared to danofloxacin (0.12 +/- 0.01 microgram/mL). The steady-state AUC0-24 h values of 12.48 and 2.88 micrograms.h/mL, respectively, derived from these plasma concentrations are comparable with corresponding area under the plasma concentration-time curve (AUC) values after single oral administration. For both drugs, tissue concentrations markedly exceeded plasma concentrations, e.g. in the target lung, tissue concentrations of 0.31 +/- 0.07 microgram/g for danofloxacin and 0.88 +/- 0.24 microgram/g for enrofloxacin were detected. Taking into account the similar in vitro activity of danofloxacin and enrofloxacin against important pathogens in chickens, a higher therapeutic efficacy of water medication for enrofloxacin compared to danofloxacin can be expected when given at the approved dosages.  相似文献   

16.
Six dogs were treated with a single intravenous (i.v.) dose (2 mg/kg) of marbofloxacin, followed by single oral (p.o.) doses of marbofloxacin at 1, 2 and 4 mg/kg, according to a three-way crossover design. The same experimental design was used for the subcutaneous (s.c.) route. In addition, a long-term trial involving eight dogs given oral doses of marbofloxacin at 2, 4 and 6 mg/kg/day for thirteen weeks was carried out. Plasma and urine samples were collected during the first two trials, plasma and skin samples were collected after the second of these trials. Plasma, urine and skin concentrations of marbofloxacin were determined by a reverse phase liquid chromatographic method. Mean pharmacokinetic parameters after i.v. administration were the following: t1/2β=12.4h; Cl B= 0.10 L/h.kg; V area= 1.9 L/kg. The oral bioavailability of marbofloxacin was close to 100% for the three doses. At 2 mg/kg, C max of 1.4 μg/mL was reached at t max of 2.5 h. Mean AUC and C max values had a statistically significant linear relationship with the doses administered. About 40% of the administered dose was excreted in urine as unchanged parent drug. After s.c. administration, the calculated parameters were close to those obtained after oral administration, except t max (about 1 h) which was shorter. The mean skin to plasma concentration ratio after the long-term trial was 1.6, suggesting good tissue penetration of marbofloxacin.  相似文献   

17.
Detection of enrofloxacin and its metabolite ciprofloxacin in equine hair   总被引：4，自引：0，他引：4  
Hair analysis to detect drug administration has not been studied extensively in horses. This study aimed to (a) develop an analytical method for enrofloxacin and its metabolite ciprofloxacin in mane and tail hair, (b) relate measured values to doses, routes of administration, hair colour, and (c) demonstrate long-term detectability. Samples were extracted in trifluoroacetic acid at 70 degrees C. Extracts were cleaned-up by solid-phase extraction and analysed by high-performance liquid chromatography with UV-diode array detection. Analyte recoveries were > 87%. Horses were sampled after therapeutic enrofloxacin administration either orally at 7.5 mg/kg daily for 3-13 days or twice daily for 10-14 days (Group 1, n=7) or intravenously at 5.0 mg/kg daily for 12 and 15 days (Group 2, n=2). Enrofloxacin and ciprofloxacin were detected at concentrations up to 452 and 19 ng/mg, respectively, up to 10 months post-treatment. In vitro, enrofloxacin and ciprofloxacin were extensively bound to melanin (> 96%) and in vivo, their uptake was 40-fold greater in black than white hair. Enrofloxacin and ciprofloxacin concentrations correlated to enrofloxacin dose (r2=0.777 and r2=0.769). Enrofloxacin:ciprofloxacin ratios were 21:1 and 13:1 following intravenous and oral administration, respectively. Longitudinal analyte distributions correlated to treatment-sampling interval.  相似文献   

18.
OBJECTIVES: To determine pharmacokinetic characteristics of marbofloxacin after a single IV and oral administration and tissue residues after serial daily oral administration in chickens. ANIMALS: 40 healthy broiler chickens. PROCEDURE: Two groups of chickens (groups A and B; 8 chickens/group) were administered a single IV and oral administration of marbofloxacin (2 mg/kg). Chickens of group C (n = 24) were given serial daily doses of marbofloxacin (2 mg/kg, PO, q 24 h for 3 days). Plasma (groups A and B) and tissue concentrations (group C) of marbofloxacin and its major metabolite N-desmethyl-marbofloxacin were determined by use of high-performance liquid chromatography. Residues of marbofloxacin and N-desmethylmarbofloxacin were measured in target tissues. RESULTS: Elimination half-life and mean residence time of marbofloxacin in plasma were 5.26 and 4.36 hours after IV administration and 8.69 and 8.55 hours after oral administration, respectively. Maximal plasma concentration was 1.05 microg/ml, and interval from oral administration until maximum concentration was 1.48 hours. Oral bioavailability of marbofloxacin was 56.82%. High concentrations of marbofloxacin and N-desmethyl-marbofloxacin were found in the kidneys, liver, muscles, and skin plus fat 24 hours after the final dose of marbofloxacin; however, marbofloxacin and N-desmethyl-marbofloxacin were detected in only hepatic (27.6 and 98.7 microg/kg, respectively) and renal (39.7 and 69.1 microg/kg, respectively) tissues 72 hours after termination of marbofloxacin treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of pharmacokinetic data obtained in this study reveals that a minimal therapeutic dose of 2 mg/kg, PO, every 24 hours should be appropriate for control of most infections in chickens.  相似文献   

19.
The pharmacokinetics of a single dose of enrofloxacin administered orally, both pilled and in fish, and i.v. to African penguins (Spheniscus demersus) at 15 mg/kg were determined. Plasma concentrations of enrofloxacin and its metabolite ciprofloxacin were measured via high-pressure liquid chromatography with mass spectrometry. An i.v. administration of enrofloxacin resulted in an extrapolated mean plasma concentration of 7.86 microg/ml at time zero. Plasma volume of distribution for i.v. administration was 3.00 L/kg, with a mean elimination half-life of 13.67 hr and a mean total body clearance rate of 3.03 ml/min/kg. Oral administration of enrofloxacin achieved a mean maximum plasma concentration of4.38 microg/ml at 4.8 hr after administration when pilled, whereas mean maximum plasma concentration was 4.77 microg/ml at 1.59 hr after administration when given in fish. Mean terminal elimination half-life was 13.79 hr pilled and 11.93 hr when given in fish. Low concentrations of ciprofloxacin were detected after both oral and i.v. enrofloxacin administration. Enrofloxacin administered to African penguins at 15 mg/kg p.o.q. 24 hr, whether in fish or pilled, is expected to achieve the surrogate markers of efficacy for bacteria with a minimum inhibitory concentration of 0.5 microg/ml or less; however, clinical studies are needed to determine efficacy.  相似文献   

20.
This study describes the pharmacokinetics of enrofloxacin following oral and i.v. administration to goral (Nemorrhaedus goral arnouxianus). The objective of this study was to expand upon current antimicrobial treatment options available for use in goral by measuring plasma concentrations and examining the pharmacokinetics of enrofloxacin in these animals. Two single-dose treatments of enrofloxacin were administered to four goral in a crossover design. Single-dose treatments consisted of administration of injectable enrofloxacin i.v. (5 mg/kg) and enrofloxacin tablets (136 mg chewable tablets) dissolved in a grain slurry and administered p.o. (10 mg/kg). Plasma levels of enrofloxacin and its metabolite ciprofloxacin were measured with the use of high-performance liquid chromatography with UV detection. Plasma volume of distribution for i.v. enrofloxacin was 2.15 - 1.01 L/kg, with a mean elimination half-life of 13.3 hr and total body clearance of 0.19+/-0.14 L/kg/hr. The maximum plasma concentration measured for oral enrofloxacin was 2.77 microg/ml, with a mean half-life of 5.2 hr and systemic availability of 14.6%. The area under the plasma concentration over time curve (AUC) for oral enrofloxacin was 21.06 microg/hr/ml. The area under the plasma concentration over time curve generated for oral enrofloxacin in goral yields an area under the plasma concentration over time curve to minimum inhibitory concentration ratio > 100 for many gram-positive and gram-negative bacterial pathogens common to small ruminants. Based on these results, oral enrofloxacin may be considered for further study as a treatment option for susceptible infections in goral.  相似文献   

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