Pharmacokinetics following intravenous administration and pharmacodynamics of cefquinome in buffalo calves.

Disposition following single intravenous injection (2 mg/kg) and pharmacodynamics of cefquinome were investigated in buffalo calves 6-8 months of age. Drug levels in plasma were estimated by high-performance liquid chromatography. The plasma concentration-time profile following intravenous administration was best described by a two-compartment open model. Rapid distribution of cefquinome was evident from the short distribution half-life (t ½ α = 0.36 ± 0.01 h), and small apparent volume of distribution (Vd area = 0.31 ± 0.008 L/kg) indicated limited drug distribution in buffalo calves. The values of area under plasma concentration-time curve, elimination half-life (t ½ β ), total body clearance (ClB), and mean residence time were 32.9 ± 0.56 μg · h/mL, 3.56 ± 0.05 h, 60.9 ± 1.09 mL/h/kg, and 4.24 ± 0.09 h, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration of cefquinome were 0.035-0.07 and 0.05-0.09 μg/mL, respectively. A single intravenous injection of 2 mg/kg may be effective to maintain the MIC up to 12 h in buffalo calves against the pathogens for which cefquinome is indicated.