Pharmacokinetics and tissue residues of vancomycin after oral administration in crucian carp

The pharmacokinetics and tissue residues of vancomycin in crucian carp (Carassius auratus) were studied after oral administration of a single dosage of 1 mg/kg body weight at water temperature of 18 degrees C. The drug concentration-time data were fitted using a two-compartment open model with first-order absorption. The vancomycin concentrations in plasma and tissues including muscle, liver and kidney were analyzed by means of liquid chromatography-tandem mass spectrometry. As a result, the plasma absorption rate constant of vancomycin was 3.75/hr and the time point of maximum concentration in plasma was 3.0 hr respectively. The maximum concentration of vancomycin in plasma was 216.58 mu g/L. The distribution half-life and the elimination half-life in plasma were 6.69 hr and 190 hr, as well as the absorption half-life of plasma was 0.19/hr. The area under the plasma concentration-time curve of plasma was 15.12 mg hr/L. The apparent volume of distribution of plasma was estimated to be 4.45 L/kg and the total body clearance was computed as 0.061 L hr(-1) kg(-1). In addition, the maximum tissue concentrations of vancomycin were in the order of liver > kidney > muscle. To guarantee the safety of tissue samples for consumption, it was suggested that the withdrawal time should not be less than 30 days at 18 degrees C. All these results may provide guidance for future vancomycin treatment in aquaculture.