Following oral administration of the therapeutic dosage of 3 mg/kg to dogs, Veraflox® is rapidly (Tmax of 2 hours) and almost completely (approximately 100%) absorbed, reaching peak serum concentration of 1.6 mg/l. Repeated daily dosing for 28 days had no impact on the pharmacokinetic profile, with an accumulation index of 1.1. A linear relationship between pradofloxacin serum concentrations and the administered dose is observed in dogs within a tested dose range of 1 to 9 mg/kg body weight 5.
The high volume of distribution (Vd) of greater than 2 l/kg body weight indicates good tissue penetration. This pharmacokinetic term can be defined as the volume of fluid that would be required to contain the amount of drug in the body if it were uniformly distributed at a concentration equal to that in plasma 6. Administration of 3 mg/kg pradofloxacin to a 10 kg dog with a known Vd of 2.3 l/kg for pradofloxacin in dogs, this means a total body fluid volume of 23 l is needed. This largely exceeds the plasma volume of a 10 kg dog indicating large diffusion of the drug in extravascular fluid compartments (tissues).
Pradofloxacin is eliminated from serum with a terminal half-life of 7.2 hours. It is cleared from the body at 0.24 l/h/kg. Mean Residence Time in the body is 9.7 hours.
Serum pharmacokinetic profile of pradofloxacin tablets in dogs
Cmax: maximum concentration
Tmax: time of maximum concentration
AUC0-24h: area under the concentration vs time curve (24h interval)
AUCinf: area under the concentration vs time curve (unlimited)
MRT: mean residence time
V: volume of distribution