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 (ClB) 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.
Animals ; Anti-Bacterial Agents/administration&dosage/*pharmacokinetics ; Area Under Curve ; Buffaloes/*metabolism ; Ceftriaxone/administration&dosage/*pharmacokinetics ; Drug Administration Schedule/veterinary ; Fever/drug therapy/*metabolism/*veterinary ; Half-Life ; Lipopolysaccharides/administration&dosage ; Male ; Metabolic Clearance Rate

To determine the effect of exogenous 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] combined with induced parturition on calcium (Ca) metabolism, cows received a single intramuscular injection of 1,25(OH)2D3 and prostaglandin F2alpha (PGF2alpha) closely before calving. Ten late-pregnant, multiparous Holstein cows were assigned to 1,25(OH)2D3 group (five treated with both 1,25(OH)2D3 and PGF2alpha) and control group (five treated with PGF2alpha). 1,25(OH)2D3 group showed an increase in plasma Ca concentration around parturition, whereas control group revealed a decrease in plasma Ca level. Plasma Ca concentration in 1,25(OH)2D3 group were significantly higher than that in control group during .0.5 to 3 days after parturition.
Animals ; Calcitriol/*pharmacology ; Calcium/blood/*metabolism ; Cattle/*metabolism ; Dinoprost/*pharmacology ; Drug Administration Schedule/veterinary ; Female ; Injections, Intramuscular/veterinary ; Magnesium/blood ; Parturient Paresis/prevention&control ; Parturition/blood/*metabolism ; Phosphorus/blood ; Pregnancy ; Statistics, Nonparametric