Plasma pharmacokinetics and dosage regimen of cefpirome sulfate in ewes

Cefpirome is fourth- generation cephalosporin class of drug with a broad spectrum of activity against Gram- positive and Gram- negative organisms. A pharmacokinetic study of single dose intravenous (IV) and intramuscular (IM) administration of cefpirome sulfate (10 mg/kg body weight) was conducted using High Performance Liquid Chromatography (HPLC) and the pharmacokinetic parameters established were utilized to calculate optimal dosage regimens in ewes. Following IV administration of cefpirome in ewes the mean value of the elimination rate constant (beta), elimination half life (t(1/2 beta)), the area under the plasma drug concentration-time curve (AUC(0-infinity)), the area under the first moment of the plasma drug concentration (AUMC), the mean residence time (MRT), the apparent volume of distribution (Vd(area)) and total body clearance (Cl-B) were 0.43 +/- 0.04 h(-1), 1.68 +/- 0.21 h, 82.71 +/- 3.76 mu g.h/mL, 211.06 +/- 23.99 mu g.h(2)/mL, 2.51 +/- 0.19 h, 0.28 +/- 0.03 L/kg and 0.11 +/- 0.00 L/h/kg, respectively, while following IM administration of cefpirome the mean values were 0.33 +/- 0.01 h(-1), 2.04 +/- 0.06 h, 73.27 +/- 4.04 mu g.h/mL, 229.02 +/- 20.32 mu g.h(2)/mL, 3.09 +/- 0.12 h, 0.45 +/- 0.03 L/kg and 0.14 +/- 0.01 L/h/kg, respectively. The bioavailability following IM administration of cefpirome was 88.85 +/- 4.07 %. Cefpirome concentration in plasma was maintained above the target MIC (>= 0.25 mu g/mL) for 12 h. The therapeutic dosage regimen calculated using the pharmacokinetic parameters generated by the intravenous route of drug administration indicated the most appropriate dose of cefpirome to maintain MIC at >= 0.25 mu g/mL with a dosage interval of 12 h, would be 13.00 mg/kg body weight in ewes.