Pharmacokinetics and ex‐vivo pharmacodynamics of cefquinome against Klebsiella pneumonia in healthy dogs

A two‐period cross‐over study was carried to investigate the pharmacokinetics (PK) and ex‐vivo pharmacodynamics (PD) of cefquinome when administrated intravenously (IV) and intramuscularly (IM) in seven healthy dogs at a dose of 2 mg/kg of body weight. Serum concentrations were determined by HPLC‐MS/MS assay and cefquinome concentration vs. time data after IV and IM were best fit to a two‐compartment open model. Cefquinome mean values of area under concentration–time curve (AUC) were 5.15 μg·h/mL for IV dose and 4.59 μg·h/mL for IM dose. Distribution half‐lives and elimination half‐lives after IV dose and IM dose were 0.27 and 0.44 h, 1.53 and 1.94 h, respectively. Values of total body clearance (Cl_B) and volume of distribution at steady‐state (V_ss) were 0.49 L·kg/h and 0.81 L/kg, respectively. After IM dose, C_max was 2.53 μg/mL and the bioavailability was 89.13%. For PD profile, the determined MIC and MBC values against K. pneumonia were 0.030 and 0.060 μg/mL in MHB and 0.032 and 0.064 μg/mL in serum. The ex vivo time‐kill curves also were established in serum. In conjunction with the data on MIC, MBC values and the ex vivo bactericidal activity in serum, the present results allowed prediction that a single cefquinome dosage of 2 mg/kg may be effective in dogs against K. pneumonia infection.