Temperature-dependent pharmacokinetics and tissue distribution of oxolinic acid in sea bass, Dicentrarchus labrax L., after a single intravascular injection

The pharmacokinetics and tissue distribution of oxolinic acid following an intravascular administration (15 mg kg^?1 fish) were determined in sea bass, Dicentrarchus labrax L. (110 g), at 13 °C and 22 °C water temperature. The kinetic profile of the drug was found to be temperature dependent, with increased temperature having a greater effect on distribution after equilibrium and the elimination phase than on the distribution process. The distibution half‐life of oxolinic acid was 1.15 and 2.76 h at 22 °C and 13 °C respectively, whereas the elimination half‐life of the drug was 55 h at 22 °C and 315 h at 13 °C. The values of the apparent volume of distribution (1.44 L kg^?1 at 22 °C and 3.31 L kg^?1 at 13 °C) and the volume of distribution at steady state (5.2 and 14.7 L kg^?1 at the high and low temperature respectively) were considerably different between the two tested temperatures. The total body clearance of the antibiotic was found to be low (1.47 L kg^?1 day^?1 at 22 °C and 0.80 L kg^?1 day^?1 at 13 °C). Lower rates of elimination were found for the liver compared with muscle, the difference increasing with increasing temperature, while elimination rates from the serum were higher than those of other tissues, especially at the high temperature.