ESTIMATION OF A DOSE OF MARBOFLOXACIN FOR 3-WEEK-OLD GOATS BY POPULATION ANALYSIS.

Abstract

A dose of marbofloxacin (MFX) to treat gastrointestinal infections caused by E. coli in 3-week-old goats was estimated. The pharmacodynamics of MFX against E. coli was evaluated in vitro by estimation of minimum inhibitory concentration (MIC), minimum bactericide concentration (MBC) and mutant prevention concentration (MPC). Marbofloxacin was administered to six 3-week-old goats by subcutaneous route at the dose of 2 mg/kg. The pharmacokinetic parameters were estimated by non-compartmental analysis. The dose of MFX capable to protect the 95% of population was calculated considering the population distribution of pharmacokinetic parameters. The efficacy of MFX was evaluated by the relationship between the area under curve and MPC (AUC/MPC) with a cut-off value of 22 h. The results showed that the estimated dose of MFX to reach the clinical outcome of gastrointestinal infections caused by E. coli and to prevent the bacterial resistance at the 95% of the population of 3-week-old goats was 3,179 mg/kg, which for practical reasons was fixed at 3,5 mg/kg. The in vivo efficacy of dose estimated will be tested in future studies.