Pharmacokinetics, urinary excretion and dosage regimen of ceftriaxone in crossbred cow calves following single intramuscular administration

Abstract

The pharmacokinetics and urinary excretion of ceftriaxone after I/M administration were investigated in healthy cow calves. Following single intramuscular administration of ceftriaxone (10 mg.kg^-1), appreciable concentration (0.69 ± 0.08 g.ml^-1) of drug was measured at 1 min and the peak plasma level (18.8 ± 0.68 g.ml^-1) was achieved at 30 min. The absorption and elimination half lives were 0.050 ± 0.018 hr and 6.54 ± 0.87 hr respectively. The apparent volume of distribution and total body clearance were 3.19 ± 0.42 litre kg^-1 and 0.34 ± 0.02 litre kg^-1.hr^-1 respectively. Approximately 30% of total administered dose was eliminated in urine within 24 hr of its administration. On the basis of pharmacokinetic parameters, a satisfactory intramuscular dosage regimen of ceftriaxone in cattle was calculated to be 11 mg.kg^-1) repeated at 30 hr intervals.