RESUMO
The present study was planned to investigate the pharmacokinetics of ceftriaxone in experimentally induced febrile buffalo calves (n=5). The fever was induced by intravenous injection of E.coli lipopolysaccaride (1 microgram/kg). To study the pharmacokinetics, ceftriaxone was administered at the dose rate of 10 mg/kg body wt. in all animals. At 1 min, the peak concentration of ceftriaxone was 79.4+/-2.37 microgram/ml and the drug was detected up to 6 h. The elimination rate constant was 0.35+/-0.02 /h and elimination half-life was 2.04+/-0.14 h. The apparent volume of distribution (Vd(area)) and total body clearance (Cl(B)) were 1.21+/-0.15 l/kg and 0.41+/-0.03 l/kg/h, respectively. To maintain a minimum therapeutic concentration of 1 microgram/kg, a satisfactory dosage regimen of cefriaxone in febrile buffalo calves is 19 mg/kg followed by 18 mg/kg at 8 h intervals.