A field comparison of the efficacy and tolerance of marbofloxacin in the treatment of bovine respiratory disease

Concentrations in plasma and selected tissues of marbofloxacin after oral and intravenous administration in Bilgorajska geese (Anser anser domesticus)

Aims: To determine the pharmacokinetics and tissue depletion of 2 mg/kg marbofloxacin (MBX) in Bilgorajska geese (Anser anser domesticus) after I/V and oral administration, to calculate the daily dose from experimental data and to compare it with that calculated by allometric scaling.Methods: Eight clinically normal female Bilgorajska geese were used in a three-phase study with a 3-week wash-out period between phases. In the first phase birds received I/V administration of 2 mg/kg MBX; the same dose was given orally in the second and third phases. Blood samples were collected between 0 minutes and 48 hours in the first and second phases, and samples of liver, kidney, lung, muscle and heart were collected following slaughter of birds between 6 and 48 hours in the third phase. Concentrations of MBX in plasma and tissues were analysed using HPLC. Two additional birds served as controls. The optimal dose was calculated based on a minimal inhibitory concentration (MIC) of 0.125 μg⁄mL using the observed clearance, or using clearance calculated by allometric scaling.Results: Concentrations of MBX in plasma were detectable up to 24 hours following both I/V and oral administration. Mean oral bioavailability was 26.5 (SD 7.7)%. Concentrations of MBX in all tissues were highest at 6 hours and decreased constantly up to 34 hours. The mean optimal daily dose for oral administration of MBX, calculated using the observed clearance was 10.36 (SD 2.18) mg/kg, and using predicted clearance was 5.54 (SD 0.14) mg/kg. The preliminary withdrawal time for a maximum residue limit of 0.15 mg/kg calculated for muscle was 38.4 hours, heart 33.6 hours, kidney 48.3 hours, lung 47.7 hours and liver 49.3 hours.Conclusion and Clinical Relevance: There was insufficient evidence to recommend MBX orally administered to geese at a daily dose of 2 mg⁄kg for treatment of bacteria with an MIC of 0.125 μg/mL. Further pharmacokinetic/pharmacodynamic studies in geese are recommended to determine the MBX dose regimen and its clinical efficacy in geese.

The effects of Mannheimia haemolytica and albendazole on marbofloxacin pharmacokinetics in lambs

The study aimed to define the effects of M. haemolytica and a single oral dose of albendazole on the single-dose pharmacokinetics of marbofloxacin in lambs. The pharmacokinetic-pharmacodynamic integration of marbofloxacin was applied to describe a 3 mg/kg intramuscular dose in lambs. The 6 healthy and 12 naturally infected with M. haemolytica lambs (Akkaraman, males weighing 10-15 kg and aged 2-3 months) were used in this study. In the marbofloxacin group, 6 healthy lambs received marbofloxacin. In the albendazole group after 2 weeks washout period, the same animals received marbofloxacin on 1 h after albendazole. In the diseased marbofloxacin group, 6 lambs naturally infected with M. haemolytica received marbofloxacin. In the diseased albendazole group, 6 lambs naturally infected with M. haemolytica received marbofloxacin on 1 h after albendazole. The marbofloxacin and albendazole were administered each as a single dose of 3 mg/kg intramuscular and 7.5 mg/kg oral, respectively, in the respective groups. Plasma concentration of marbofloxacin was measured with HPLC-UV and pharmacokinetic parameters were analyzed by non-compartmental model. Albendazole did not change the pharmacokinetic profiles of marbofloxacin in healthy and diseased lambs. However, M. haemolytica affected the pharmacokinetics of marbofloxacin in diseased lambs, AUC_0-24/MIC₉₀ ratio was not found to be higher than 125, but C_max/MIC₉₀ ratios was found to be higher than 10 for an MIC value of 0.25 μg/mL in all groups. The marbofloxacin dose described in this study may not be effective for the treatment of infections due to M. haemolytica in lambs, with MIC ≤ 0.25 μg/mL.

Distribution of marbofloxacin in the bronchoalveolar region in healthy calves

The purpose of this study was to clarify the distribution of marbofloxacin (MBFX) within the bronchoalveolar region of calves. Four clinically healthy calves were intramuscularly injected with a single dose of MBFX (2 mg/kg). Samples of plasma and bronchoalveolar lavage fluid (BALF) were obtained for each calf at 0 (before administration), 1, 2, 6 and 24 hr after injection of MBFX. The injections and series of sample collections were conducted and repeated again after two weeks. The results show that the MBFX concentrations in the pulmonary epithelial lining fluid (ELF) were significantly higher than that in plasma and in alveolar cells at 2 hr after injection (P<0.05). For concentrations of MBFX within the ELF, the mean area under the MBFX concentration curve calculated during the 0 to 24 hr timeframe (AUC_0–24) was significantly higher than the mean determined from samples collected from the plasma (P<0.05). These results suggest that intramuscularly injected MBFX was well distributed in the bronchoalveolar region.

Impact of Timing and Dosage of a Fluoroquinolone Treatment on the Microbiological, Pathological, and Clinical Outcomes of Calves Challenged with Mannheimia haemolytica

The efficacy of an early and low inoculum-adjusted marbofloxacin treatment was evaluated on microbiological and clinical outcomes in calves infected with 4.10⁷ CFU of Mannheimia haemolytica A1. Twenty-two calves were included based on their rectal temperature rise in the 10 h after challenge and allocated in four groups, receiving a single intramuscular injection of saline (CON), 2 mg/kg marbofloxacin 2–4 h after inclusion (early treatment, E2), 2 or 10 mg/kg marbofloxacin 35–39 h after inclusion (late treatments, L2, L10). In CON calves, M. haemolytica DNA loads in bronchoalveolar lavages continuously increased from inclusion to day 4, and were associated with persistent respiratory clinical signs and lung lesions. At times of early and late treatments, M. haemolytica loads ranged within 3.5–4 and 5.5–6 log₁₀ DNA copies/mL, respectively. Early 2 mg/kg marbofloxacin treatment led to rapid and total elimination of bacteria in all calves. The late treatments induced a reduction of bacterial loads, but 3 of 6 L2 and 1 of 6 L10 calves were still positive for M. haemolytica at day 4. Except for CON calves, all animals exhibited clinical improvement within 24 h after treatment. However, early 2 mg/kg treatment was more efficacious to prevent pulmonary lesions, as indicated by the reduction of the extension and severity of gross lesions and by the histopathological scores. These results demonstrated for the first time that a reduced antibiotic regimen given at an early stage of the disease and targeting a low bacterial load could be efficacious in a natural bovine model of pneumonia.

Pharmacokinetics/pharmacodynamics of marbofloxacin in a Pasteurella multocida serious murine lung infection model

Background

Marbofloxacin is a third-generation fluoroquinolone developed solely for veterinary medicine with a broad spectrum of antibacterial activity against some Gram-positive and most Gram-negative bacteria, including the bovine respiratory tract pathogen, Pasteurella multocida. The objective of our study was to elucidate the pharmacokinetics and pharmacodynamics of marbofloxacin in a Pasteurella multocida infected murine lung model, and to estimate the magnitudes of pharmacokinetics-pharmacodynamics parameters associated with various effects.

Results

The pharmacokinetic studies revealed marbofloxacin kinetics in infected mice were linear over a dose ranging from 1.25 to 10 mg/kg of body weight. The protein binding in the plasma of neutropenic infected mice was 29.77 %. The magnitudes of the ratio of the free-drug area under the concentration-time curve over 24 h to MIC (fAUC_0-24h/MIC) associated with static effect, a 2 log₁₀ reduction and a 3 log₁₀ reduction of bacterial counts were 40.84, 139.34, and 278.08 h, respectively.

Conclusions

Based on the dose range study, marbofloxacin exhibited concentration-dependent killing and the fAUC/MIC was the PK/PD index that correlated best with efficacy (R² = 83 %). On the basis of a bactericidal effect goal of fAUC_0-24h/MIC of 278.08 h, if marbofloxacin is used for the treatment of P. multocida serious lung infection with an MIC₉₀ of 0.12 μg/ml, the current dose (2 mg/kg) would fail to achieve a bactericidal effect. It would benefit from higher doses (4 ~ 6 mg/kg) than those commonly used in clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0608-1) contains supplementary material, which is available to authorized users.

Pharmacokinetic/pharmacodynamic relationship of marbofloxacin against Pasteurella multocida in a tissue-cage model in yellow cattle

The fluoroquinolone antimicrobial drug marbofloxacin was administered to yellow cattle intravenously and intramuscularly at a dose of 2 mg/kg of body weight in a two-period crossover study. The pharmacokinetic properties of marbofloxacin in serum, inflamed tissue-cage fluid (exudate), and noninflamed tissue-cage fluid (transudate) were studied by using a tissue-cage model. The in vitro and ex vivo activities of marbofloxacin in serum, exudate, and transudate against a pathogenic strain of Pasteurella multocida (P. multocida) were determined. Integration of in vivo pharmacokinetic data with the in vitro MIC provided mean values for the area under the curve (AUC)/MIC for serum, exudate, and transudate of 155.75, 153.00, and 138.88, respectively, after intravenous dosing and 160.50, 151.00, and 137.63, respectively, after intramuscular dosing. After intramuscular dosing, the maximum concentration/MIC ratios for serum, exudate, and transudate were 21.13, 9.13, and 8.38, respectively. The ex vivo growth inhibition data after intramuscular dosing were fitted to the inhibitory sigmoid Emax equation to provide the values of AUC/MIC required to produce bacteriostasis, bactericidal activity, and elimination of bacteria. The respective values for serum were 17.25, 31.29, and 109.62, and slightly lower values were obtained for transudate and exudate. It is proposed that these findings might be used with MIC50 or MIC90 data to provide a rational approach to the design of dosage schedules which optimize efficacy in respect of bacteriological as well as clinical cures.

Marbofloxacin

In the title compound, [systematic name: 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl­piperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-ij][1,2,4]benzoxadiazine-6-carb­oxy­lic acid], C₁₇H₁₉FN₄O₄, the carbonyl and carboxyl groups are coplanar with the quinoline ring, making a dihedral angle of 2.39 (2)°. The piperazine ring adopts a chair conformation and the oxadiazinane ring displays an envelope conformation with the CH₂ group at the flap displaced by 0.650 (2) Å from the plane through the other five atoms. The mol­ecular structure exhibits an S(6) ring motif, owing to an intra­molecular O—H⋯O hydrogen bond. In the crystal, weak C—H⋯F hydrogen bonds link mol­ecules into layers parallel to the ab plane.

Effect of marbofloxacin on Haemophilus parasuis nasal carriage

Haemophilus parasuis is a colonizer of the upper respiratory tract and the causative agent of Glässer's disease in swine. This study focused on the nasal carriage of H. parasuis after treatment with marbofloxacin. Three marbofloxacin treatments (three doses of 2mg/kg body weight [bw] every 24h, two doses of 4 mg/kg bw every 48 h and 8 mg/kg bw in one single shot) were used and all of them reduce significantly (p<0.05) the nasal carriage of H. parasuis as compared to control animals. Moreover, H. parasuis was not detected in the nasal cavities of piglets after administering the highest dose. The effect of a dose of 8 mg marbofloxacin/kg bw in one shot was further studied in a farm with clinical cases of Glässer's disease using a longitudinal study. Statistically significant reduction of nasal carriage of H. parasuis was detected during the first week after treatment in comparison with the control group. However, a clear relationship between the minimum inhibitory concentration (MIC) of the different strains, their putative virulence or the treatment group (antibiotic or control) from which they were isolated was not detected. Finally, the effect induced by the antibiotic treatment on the bacterial strains seemed to be transitory, since diverse H. parasuis strains (with high and low marbofloxacin MICs) were observed 7 days after finishing the treatment.

Pharmacokinetic and pharmacodynamic testing of marbofloxacin administered as a single injection for the treatment of bovine respiratory disease

New approaches in Pharmacokinetic/Pharmacodynamic (PK/PD) integration suggested that marbofloxacin, a fluoroquinolone already licensed for the treatment of bovine respiratory disease at a daily dosage of 2 mg/kg for 3-5 days, would be equally clinically effective at 10 mg/kg once (Forcyl(®)), whilst also reducing the risk of resistance. This marbofloxacin dosage regimen was studied using mutant prevention concentration (MPC), PK simulation, PK/PD integration and an in vitro dynamic system. This system simulated the concentration-time profile of marbofloxacin in bovine plasma established in vivo after a single 10 mg/kg intramuscular dose and killing curves of field isolated Pasteurellaceae strains of high (minimum inhibitory concentration (MIC) MIC ≤ 0.03 μg/mL), average (MIC of 0.12-0.25 μg/mL) and low (MIC of 1 μg/mL) susceptibility to marbofloxacin. The marbofloxacin MPC values were 2- to 4-fold the MIC values for all Mannheimia haemolytica, Pasteurella multocida tested. Marbofloxacin demonstrated a concentration-dependent killing profile with bactericidal activity observed within 1 h for most strains. No resistance development (MIC ≥ 4 μg/mL) was detected in the dynamic tests. Target values for risk of resistance PK/PD surrogates (area under the curve (AUC) AUC(24 h) /MPC and T(>MPC) /T(MSW) ratio) were achieved for all clinically susceptible pathogens. The new proposed dosing regimen was validated in vitro and by PK/PD integration confirming the single-injection short-acting antibiotic concept.

PK-PD integration and modeling of marbofloxacin in sheep

The fluoroquinolone antimicrobial drug, marbofloxacin, was administered intravenously (IV) and intramuscularly (IM) to sheep at a dose rate of 2 mg kg(-1) in a 2-period cross-over study. Using a tissue cage model of inflammation, the pharmacokinetic properties of marbofloxacin were established for serum, inflamed tissue cage fluid (exudate) and non-inflamed tissue cage fluid (transudate). For serum, after IV dosing, mean values for pharmacokinetic parameters were: clearance 0.48 L kg(-1) h(-1); elimination half-life 3.96 h and volumes of distribution 2.77 and 1.96 L kg(-1), respectively, for V(darea) and V(ss). After IM dosing mean values for pharmacokinetic variables were: absorption half-time 0.112 h, time of maximum concentration 0.57 h, terminal half-life (T(1/2)el) 3.65 h and bioavailability 106%. For exudate, mean T(1/2)el values were 12.38 and 13.25 h, respectively, after IV and IM dosing and for transudate means were 13.39 h (IV) and 12.55 h (IM). The in vitro minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) and ex vivo time-kill curves for marbofloxacin in serum, exudate and transudate were established against a pathogenic strain of Mannheimia haemolytica. Integration of in vivo pharmacokinetic data with MIC determined in vitro provided mean values of area under curve (AUC)/MIC ratio for serum, exudate and transudate of 120.2, 156.0 and 156.6 h after IV dosing and 135.5, 165.3 and 146.2 h after IM dosing, respectively. After IM administration maximum concentration (C(max))/MIC ratios were 21.1, 6.76 and 5.91, respectively, for serum, exudate and transudate. The ex vivo growth inhibition data after IM administration were fitted to the sigmoid E(max) (Hill) equation to provide values for serum of AUC(24h)/MIC producing, bactericidal activity (22.51 h) and virtual eradication of bacteria (35.31 h). It is proposed that these findings might be used with MIC(50) or MIC(90) data to provide a rational approach to the design of dosage schedules which optimise efficacy in respect of bacteriological as well as clinical cures.

Pharmacokinetic and pharmacodynamic modelling of marbofloxacin administered alone and in combination with tolfenamic acid in goats

In a four-period cross-over study, the fluoroquinolone antibacterial drug marbofloxacin (MB) was administered to goats intramuscularly (IM) at a dose rate of 2 mg/kg, both alone and in combination with the non-steroidal anti-inflammatory drug tolfenamic acid (TA), also administered IM at a dose rate of 2 mg/kg. Using a tissue cage model of inflammation, based on the irritant actions of carrageenan, the pharmacokinetics (PK) of MB and MB in combination with TA were determined. MB mean values of area under concentration-time curve (AUC) were similar for serum (5.60 microg h/mL), inflamed tissue cage fluid (exudate; 5.32 microg h/mL) and non-inflamed tissue cage fluid (transudate; 4.82 microg h/mL). Values of mean residence time (MRT) of MB in exudate (15.5 h) and transudate (15.8 h) differed significantly from serum MRT (4.23 h). Co-administration of TA did not affect the PK profile of MB. The pharmacodynamics of MB were investigated using a caprine strain of Mannheimia haemolytica. Integration of PK data with ex vivo bacterial time-kill curve data for serum, exudate and transudate provided AUC(24h)/minimum inhibitory concentration (MIC) ratios of 160, 133 and 121 h, respectively, for the strain of organism used. Modelling of the ex vivo time-kill data to the sigmoid E(max) equation provided AUC(24h)/MIC values required for bacteriostatic and bactericidal actions of MB and for virtual eradication of the organism of 27.6, 96.2 and 147.3 h, respectively. Corresponding values for MB+TA were 20.5, 66.5 and 103.0 h. These data were used to predict once daily dosage schedules of MB for subsequent clinical evaluation.

Comparative pharmacokinetics of marbofloxacin in healthy and Mannheimia haemolytica infected calves

The pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and Mannheimia haemolytica naturally infected (n=8) Simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. The concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. Following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (MRT) were significantly longer in diseased calves (8.2h; 11.13 h) than in healthy ones (4.6 h; 6.1 h), respectively. The value of total body clearance (CL(B)) was larger in healthy calves (3 ml min(-1) kg(-1)) than in diseased ones (1.3 ml min(-1) kg(-1)). After single intramuscular (i.m.) administration of the drug, the elimination half-life, mean residence time (MRT) and maximum plasma concentration (C(max)) were higher in diseased calves (8.0, 12 h, 2.32 microg ml(-1)) than in healthy ones (4.7, 7.4 h, 1.4 microg ml(-1)), respectively. The plasma concentrations and AUC following administration of the drug by both routes were significantly higher in diseased calves than in healthy ones. Protein binding of Marbofloxacin was not significantly different in healthy and diseased calves. The mean value for MIC of marbofloxacin for M. haemolytica was 0.1+/-0.06 microg ml(-1). The C(max)/MIC and AUC(24)/MIC ratios were significantly higher in diseased calves (13.0-64.4 and 125-618 h) than in healthy calves (8-38.33 and 66.34-328 h). The obtained results for surrogate markers of antimicrobial activity (C(max)/MIC, AUC/MIC and T > or = MIC) indicate the excellent pharmacodynamic characteristics of the drug in diseased calves with M. haemolytica, which can be expected to optimize the clinical efficacy and minimize the development of resistance.

Rapid depletion of marbofloxacin residues in rabbit after therapeutic treatment

Although rabbit meat production represents a very small percentage of the world meat market, this percentage has been growing continuously during the last 30 years. Rabbit is considered a minor food species, and therefore no drugs are specifically registered for this animal. This situation encourages rabbit farmers to make off-label use of antibacterial drugs authorized for food-producing animal species other than rabbits. In the present study, the distribution and elimination of the fluoroquinolone antibacterial agent marbofloxacin in rabbit muscle, liver, and kidney was investigated. Marbofloxacin was chosen as a representative of a new generation of antibacterial drugs active against most gram-positive and gram-negative bacteria and mycoplasms; it is well tolerated and has short elimination times in bovine and swine species. Rabbits were treated with marbofloxacin at 2 mg kg of body weight(-1) for 5 days. Residual concentrations in liver, kidney, and muscle tissues were determined posttreatment with high-performance liquid chromatography and fluorescence detection. Marbofloxacin was rapidly distributed and eliminated from rabbit tissues. Concentrations were higher in the liver and kidney than in muscle. However, 48 h after the end of treatment, marbofloxacin concentrations dropped below the maximum residue level fixed for this antibacterial drug in cattle and pigs. Considering the efficacy of marbofloxacin for the treatment of the most common rabbit diseases, its tolerability, and its short elimination time as verified in the present study, use of this antibacterial drug could be extended to therapeutic treatment of rabbits.