Disposition kinetics of kanamycin in mules

The disposition kinetics of kanamycin was investigated following an injection of a single intravenous dose 5 mg/kg body mass in healthy adult female mules. Blood samples collected at various time intervals post-medication were analyzed for kanamycin by microbiological assay. The plasma drug concentration versus time data was best fitted by a biexponential expression. Macro-kinetic parameters were computed for a two-compartment open model. Values for distribution half-life (t1/2á)) and elimination half-life (t1/2 ß) were 0.18 ± 0.26 and 4.39 ± 0.68 h, respectively. The apparent volume of distribution (Vd) was 0.64 ± 0.17 L/kg. Total body clearance (ClB) of the drug was 1.66 ± 0.22 ml/ min.kg. Existing dosage of 5 mg/kg body mass at 24 h intervals does not maintain the desired minimum inhibitory concentration (MIC) at the end of proposed dosing intervals. Calculated optimal dosage regimen for kanamycin in mules was 8.73 and 7.45 mg/kg body mass for priming and maintenance, respectively, for a dosage interval of 12 h to maintain the concentration of 2 μg/ml in blood.