Pharmacokinetics of Marbofloxacin After Oral Administration to Eurasian Buzzards (Buteo buteo)

Marbofloxacin is a bactericidal fluoroquinolone developed exclusively for veterinary medicine. The pharmacokinetic disposition of this drug was studied after oral administration of a single dose (10 mg/kg) to 8 adult Eurasian buzzards (Buteo buteo). Plasma concentrations of marbofloxacin were measured during the 48-hour period after drug administration. A maximum plasma concentration of 3.70 mu g/ml was achieved at 2.92 hours. Marbofloxacin was relatively slowly absorbed after oral administration (absorption half-life of 1.57 hours) and demonstrated a high bioavailability (92.15%). The elimination half-life was 9.48 hours, and the mean residence time was 10.65 hours. When using a minimum inhibitory concentration (MIC) breakpoint of 0.25 mu g/ml, the calculated antimicrobial efficacy of orally administered marbofloxacin was higher than the range considered optimal for a dosing regimen against pathogens with an equivalent MIC. A dosage of 10 mg/kg administered once daily appears to be appropriate for the treatment of most infections with gram-negative bacteria that affect Eurasian buzzards.