PHARMACOKINETICS OF A SINGLE INTRAVENOUS ENROFLOXACIN DOSE IN SCIMITAR-HORNED ORYX (ORYX DAMMAH)

Based on a 1.3 mg/kg mean dosage determined by metabolic energy scalin g, enrofloxacin pharmacokinetics of a single i.v. dose of enrofloxacin in five adult scimitar-horned oryx (Oryx dammah) were determined. Dru g concentration versus time curves were best fit by residual analysis to a one-compartment open model with a maximum (mean +/- SD) serum con centration after distribution of 1.887 +/- 0.632 mu g/ml and an elimin ation half-life of 41.2, +/- 27.5 min. Model-independent parameters we re area under the curve (173.63 +/- 147.5 mu g.min/ml), mean volume of distribution (steady state) (0.80 +/- 0.30 L/kg), clearance (12.07 +/ - 7.12 ml/min/kg), and residence time (77.22 +/- 72.8 min). Mean serum enrofloxacin concentrations reached the recommended minimum inhibitor y concentration (1.0 mu g/ml). Drug concentrations remained above the minimum inhibitory concentration of most sensitive bacteria (0.5 mu g/ ml) consistently for 90 min. Based on this study, enrofloxacin would h ave to be administered parenterally to scimitar-horned oryx at 1.6 mg/ kg every 6-8 hr (minimally) to maintain appropriate serum concentratio ns against susceptible bacteria. The metabolic energy scaled dose regi men from this study appeared to be too low for the oryx.