Pharmacokinetics of sarafloxacin in pigs and broilers following intravenous, intramuscular, and oral single-dose applications

Pharmacokinetics of sarafloxacin, a fluoroquinolone antibiotic, was determi ned in pigs and broilers after intravenous (i.v.), intramuscular (i.m.), or oral (p.o.) administration at a single dose of 5 (pigs) or 10 mg/kg broile rs). Plasma concentration profiles were analysed by a noncompartmental phar macokinetic method. Following i.v., i.m. and p.o. doses, the elimination ha lf-lives (t(1/2 beta)) were 3.37 +/- 0.46, 4.66 +/- 1.34, 7.20 +/- 1.92 (pi gs) and 2.53 +/- 0.82, 6.81 +/- 2.04, 3.89 +/- 1.19 h (broilers), respectiv ely. After i.m. and p.o. doses, bioavailabilities (F) were 81.8 +/- 9.8 and 42.6 +/- 8.2% (pigs) and 72.1 +/- 8.1 and 59.6 +/- 13.8% (broilers), respe ctively. Steady-state distribution volumes (V-d(ss)) of 1.92 +/- 0.27 and 3 .40 +/- 1.26 L/kg and total body clearances (Cl-B) of 0.51 +/- 0.03 and 1.2 0 +/- 0.20 L/kg/h were determined in pigs and broilers, respectively. Areas under the curve (AUC), mean residence times (MRT), and mean absorption tim es (MAT) were also determined. Sarafloxacin was demonstrated to be more rap idly absorbed, more extensively distributed, and more quickly eliminated in broilers than in pigs. Based on the single-dose pharmacokinetic parameters determined, multiple dosage regimens were recommended as: a dosage of 10 m g/kg given intramuscularly every 12 h in pigs, or administered orally every 8 h in broilers, can maintain effective plasma concentrations with bacteri a infections, in which MIC90 are <0.25 <mu>g/mL.