Pharmacokinetics of Marbofloxacin in Loggerhead Sea Turtles (Caretta caretta) after Single Intravenous and Intramuscular Doses

The disposition kinetics of marbofloxacin at a single dose of 2 mg/kg bodyweight were determined in a crossover trial with five clinically healthy loggerhead sea turtles (Caretta caretta) after i.v. and i.m. administration. Marbofloxacin plasma concentrations were determined by high-performance liquid chromatog- raphy (LOD/LOQ 0.05 mg/ml). Data were subjected to noncompartmental analysis. The integrated pharmacoki- netic/pharmacodynamic variables showed that optimal area under the curv e( AUC 0-24 h): minimal inhibitory concentration (MIC) (.125) and Cmax :M IC ( .8) ratios, as reported for concentration-dependent bactericidal antimicrobials (e.g., fluoroquinolones), were achievable with both a once daily i.v. or i.m. dose for microorganisms with MIC # 0.5 mg/ml, while a Cmax :M IC. 8 for MIC $ 1 mg/ml was achievable only after the i.v. administration. The absence of adverse reactions in the animals after i.v. or i.m. administration of marbofloxacin and the favorable pharmacokinetic/pharmacodynamic properties after a single dose of 2 mg/kg suggest the possibility of its safe and effective clinical use in loggerhead sea turtles.