Pharmacokinetic and Pharmacodynamic Evaluation of Marbofloxacin in Pig against Korean Local Isolates of Actinobacillus pleuropneumoniae

The pharmacokinetics of marbofloxacin in pigs after intravenous (i.v.), intramuscular (i.m.), and peroral (p.o.) administration and pharmacokinetic/pharmacodynamic indices of this drug against Korean local isolates of Actinobacillus pleuropneumoniae were determined in this study. Marbofloxacin (2.50 mg/kg of body weight) was administered, and blood samples were collected with designated time intervals. Plasma-extracted marbofloxacin was injected into the LC-MS/MS system. The in vitro and ex vivo antibacterial activities of marbofloxacin were evaluated against 20 isolates of A. pleuropneumoniae. The mean peak plasma concentrations (Cmax) after i.v., i.m., and p.o administration were 2.60±0.10, 2.59±0.12, and 2.34±0.12 µg/mL at 0.25±0.00, 0.44±0.10, and 1.58±0.40 h, respectively. The area under the plasma concentration-time curves (AUC0–24) and elimination half-lives were 24.80±0.90, 25.80±1.40, and 23.40±5.00 h·μg/mL and 8.60±0.30, 12.80±1.10, and 8.60±0.00 h, for i.v., i.m., and p.o. administration, correspondingly. The AUC0–24/MICs of marbofloxacin after i.v., i.m., and p.o. administration were 253.86±179.91, 264.1±187.16, and 239.53±169.75 h, respectively. The Cmax/MIC values were 26.58±18.84, 26.48±18.77, and 23.94±16.97, and T>MICs were 42.80±1.01, 36.40±1.24, and 38.60±1.18 h, after i.v., i.m., and p.o. administration, respectively. Thus, marbofloxacin dosage of 2.50 mg/kg of body weight by i.v., i.m., and p.o. administration with 24 h dosing interval will provide effective treatment for the infection of pig by A. pleuropneumonia.