Pharmacokinetics, urinary excretion and plasma protein binding of ofloxacin in water buffalo calves (Bubalus bubalis).
The disposition kinetics and urinary excretion study of levofloxacin was conducted in 5 male cross-bred calves following its single intravenous administration (4mgkg(-1)) concurrently with meloxicam (0.5mgkg(-1)). Levofloxacin was estimated by microbiological assay. The drug levels above MIC(90) in plasma, were detected up to 10h. Disposition kinetic parameters were calculated by two-compartment open model. Rapid distribution of levofloxacin was evidenced by a small distribution half-life (0.13±0.01h) and high K(12)/K(21) ratio (2.21±0.15). High ratio of AUC/MIC (90.2±3.41) indicated good antibacterial activity of levofloxacin. The AUC, Vd(area), elimination half-life, MRT and total body clearance were 9.02±0.34μgml(-1)h, 1.38±0.05lkg(-)1, 2.16±0.08h, 2.58±0.11h and 0.45±0.02lkg(-1)h(-1), respectively. About 38.4% of the administered dose of levofloxacin was excreted in urine within 24h. A suitable intravenous dosage regimen for levofloxacin would be 1.8mgkg(-1) repeated at 8h intervals when prescribed with meloxicam in calves.