The disposition of four therapeutically important antimicrobial agents was studied in llamas following intravenous bolus administration. Six llamas were each given ampicillin, tobramycin, trimethoprim and enrofloxacin at a dose of 12 mg/kg, 1 mg/kg, 3 mg/kg and 5 mg/kg of body weight with a wash out period of 3 days between each treatment. Plasma concentrations of these antimicrobial agents over 12 hours following IV bolus dosing were determined by reverse phase HPLC. Dispositions of these four antimicrobial agents were described by two compartment open model with elimination from the central compartment, and also by non-compartmental methods. From compartmental analysis, the elimination rate constant, half-life, and apparent volume of distribution in the central compartment were determined. Statistical moment theory was used to determine non-compartmental pharmacokinetic parameters of mean residence time, clearance, and volume of distribution at steady-state. Based on the disposition parameters determined, a dose and dosing interval for each of the four antimicrobial agents was suggested for llamas. Steady state peak and trough plasma levels were also predicted for the drugs in this study for llamas. / Graduation date: 1994

Graduation date: 1998