PHARMACOKINETICS OF ENROFLOXACIN IN CALVE S

Pharmacokinetic absortion and distribution of commercial enrofloxacin administered as a single intravenous, an intramuscular or oral dose (5 mg/kg) to calves were determined. Serum concentrations were obtained by the microbiological method, using Bacillus subtilis BGA, and analiz ed by AUC-RPP pharmacokinetic software (Ritschel, 1986). The following average values were obtained, via intravenous route: t 1/2: 3.53 +/- 0.67 hours; Vdss. 1.19 +/- 0.1 It/kg; total clearance: 3.83 +/- 0.25 m l/min/kg; AUC: 1321.2 +/- 97.2 mu g/ml/min. For the intramuscular and oral routes the average values of Cmax and Tmax were 1.66 +/- 0.61 mu g/ml at 60 minutes and 1.49 +/- 0.49 mu g/ml at 120 minutes respective ly. The relative bioavailability was 90.7 and 69.81% for intramuscular and oral routes respectively. A higher relative bioavailability for t he intramuscular route, good tissue perfussion and antimicrobial level s after 12 hours post administration were observed.