Abstract

INFLUENCE OF TRIKATU PRETREATMENT ON THE PHRMACOKINETICS OF LEVOFLOXACIN IN CROSSBRED COW CALVES FOLLOWING INTRAMUSCULAR ADMINISTRATION

Monika Agrawal and Nitesh Kumar*

Abstract

Pharmacokinetic study of levofloxacin was carried out in six crossbred cow calves of 9 - 12 months of age weighing 70 - 90 kg. Levofloxacin was given intramuscularly at the dose rate of 4 mg/kg body weight in six crossbred cow calves. Levofloxacin concentration was estimated at different intervals (0.042 to 24 h) by microbiological assay method using E. coli (ATCC 25922) as test organism. Kinetic parameters were calculated by using one compartment open models. Attempts were made to calculate the rational dosage regimens of levofloxacin on the basis of kinetic data and maintenance of therapeutic concentrations in plasma. Following intramuscular administration of levofloxacin, the peak plasma concentrations of levofloxacin (12.25 μg/ml) was observed at 1 h. The elimination half- life (t1/2 β), mean resident time (MRT), volume of distribution (Vdarea) and total body clearance (ClB) of levofloxacin were 3.502 h, 4.82 h, 0.306 L/kg and 60.323 ml/kg/h, respectively. The therapeutic plasma concentrations of levofloxacin were maintained at or above 0.1 μg/ml from 0.083 to 24 h. For maintaining therapeutic concentration of 0.2 μg/ml, a very lower loading dose (D*) of around 0.71 mg/kg and maintenance dose (D0) of 0.64 mg/kg may be used at the dosage interval of 12 h for treating systemic infections in crossbred cow calves.

Keywords: Levofloxacin, Trikatu, Crossbred cow calves, Intramuscular administration