Plasma levels, pharmacokinetics and dosage regimen of cefazolin in dogs

Abstract

In the present study plasma levels, pharmacokinetics and dosage regimen of cefazolin following its single intravenous injection (10 mg kg^-1 body weight) was investigated in healthy dogs. Cefazolin followed 2 compartment open model and first order kinetics in all the animals. The mean peak plasma cefazolin concentration at 2 min was 46.77±0.88 ug.ml^-1 whereas, its mean level at 7 hr of intravenous administration was O.61±0.07 ug.ml^-1. After 7 hr cefazolin could not be detected in the plasma. The mean biologicall elimination half life (t_1/2S) and total body clearance (dB) were 1.70±0.02 hr and 253.00±34.1 0 L.kg^-1. hr^-1, respectively, whereas tissue/plasma ratio (T/P ratio) was 1.35±0.46. At all the time during study period urine cefazolin concentration remained well above the MIC for common susceptible pathogens(0.25 ug.ml^-1). The optimum dosage regimen calculated on the basis of results of kinetic data was 10.06 mg kg-1 body weight to be repeated at 12 hr interval.