Pharmacotherapeutic group: Antibacterials for systemic use, Fluoroquinolones.

ATCvet code: QJ01MA93

Marbofloxacin is a synthetic, bactericidal antimicrobial, belonging to the fluoroquinolone group which acts by inhibition of DNA gyrase and of topoisomerase IV. It is effective against a wide range of Gram positive bacteria (including Streptococci and in particular Staphylococci) and Gram negative bacteria (Escherichia coli, Citrobacter freundii, Proteus spp., Klebsiella spp, Shigella spp., Pasteurella spp., Pseudomonas spp.) as well as Mycoplasma spp.

A secondary literature report of microbiological susceptibility data whose source included two European field surveys, each involving hundreds of canine and feline pathogens susceptible to marbofloxacin, was published in 2014.

Susceptibility break points have been determined as ≤1 µg/ml for sensitive, 2 µg/ml for intermediate and ≥4 µg/ml for resistant bacterial strains.

Marbofloxacin is not active against anaerobes, yeast or fungi. Cases of resistance have been observed in Streptococcus.

Resistance to fluoroquinolones occurs by chromosomal mutation with three mechanisms: decrease of the bacterial wall permeability, expression of efflux pump or mutation of enzymes responsible for molecule binding.

After oral administration in dogs and cats 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 and 10h in cats) predominantly in the active form in urine (2/3) and faeces (1/3).