Pharmacokinetic behaviour of enrofloxacin in greater rheas following a single-dose intramuscular administration

The pharmacokinetic behaviour of enrofloxacin in greater rheas was investigated after intramuscular (IM) administration of 15mg/kg. Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined by high performance liquid chromatography. Enrofloxacin peak plasma concentration (Cmax=3.30±0.90μg/mL) was reached at 24.17±9.17min. The terminal half-life (t1/2λ) and area under the curve (AUC) were 2.85±0.54h and 4.18±0.69μgh/mL, respectively. The AUC and Cmax for ciprofloxacin were 0.25±0.06μg/mL and 0.66±0.16μgh/mL, respectively. Taking into account the values obtained for the efficacy indices, an IM dose of 15mg/kg of enrofloxacin would appear to be adequate for treating infections caused by highly susceptible bacteria (MIC90<0.03μg/mL) in greater rheas.