Pharmacotherapeutic group: Antibacterials for systemic use, fluoroquinolones. ATCvet code: QJ01MA93
Pharmacodynamic properties
Marbofloxacin is a synthetic, bactericidal antimicrobial, belonging to the fluoroquinolone group which acts by inhibition of DNA gyrase and topoisomerase IV.
It has a broad-spectrum activity in vitro against Gram-positive bacteria (in particular staphylococci and streptococci) and Gram-negative bacteria (Escherichia coli, Enterobacter cloacae, Proteus spp., Klebsiella spp., Shigella spp., Pasteurella spp., Pseudomonas spp.) as well as Mycoplasma spp.
A report on microbiological susceptibility including two European field surveys covering hundreds of canine and feline pathogens sensitive to marbofloxacin was published in 2009
Microorganisms | MIC (μg/ml) |
Staphylococcus intermedius | 0.23-0.25 |
Escherichia coli | 0.125-0.25 |
Pasteurella multocida | 0.04 |
Pseudomonas aeruginosa | 0.94 |
MIC breakpoints have been determined for Enterobacteriaceae and Staphylococcus spp. in dogs and cats (skin, soft tissue, UTI). CLSI, July 2013 as ≤1 μg/ml for sensitive, 2 μg/ml for intermediate and ≥4 μg/ml for resistant bacterial strains to marbofloxacin.
Marbofloxacin is not active against anaerobes, yeasts or fungi.
The activity of marbofloxacin against the target bacterial species is bactericidal concentration dependant.
Resistance to fluoroquinolones occurs by chromosomal mutation with the following mechanisms: decrease in bacterial wall permeability, expression change of genes encoding for efflux pumps or mutations in genes encoding enzymes responsible for molecule binding. Plasmid-mediated resistance to fluoroquinolones, which confers reduced susceptibility, has also been described. Depending on the underlying resistance mechanism cross-resistance to other (fluoro)quinolones and co-resistance to other antimicrobial classes can occur.
Pharmacokinetic properties
After oral administration in dogs at the recommended dose of 2 mg/kg, marbofloxacin is readily absorbed and reaches maximal plasma concentrations of 1.5 μg/ml within 2 hours. Its bioavailability is close to 100%. It is weakly bound to plasma proteins (less than 10%), extensively distributed and in most tissues (liver, kidney, skin, lung, bladder, digestive tract) it achieves higher concentrations than in plasma. Marbofloxacin is eliminated slowly (t½ß = 14 h in dogs) predominantly in the active form in urine (2/3) and faeces (1/3).