Plasma pharmacokinetics of abamectin in fallow deer (Cervus dama dama) following subcutaneous administration.

The pharmacokinetics of abamectin (ABM) following a single subcutaneous administration of 200 μg/kg was evaluated in adult fallow deer by following ABM concentration in blood plasma. A nonlinear mixed effects modelling procedure was used for pharmacokinetic analysis. The time course of ABM concentration was described by a two-compartment model with first-order absorption. Abamectin absorption in fallow deer was rapid with a peak plasma concentration of 120.7 ± 33.2 ng/mL observed at 19.1 ± 7.7 h (mean ± SD). Half-lives of the distribution and terminal phase were 17.2 and 119.3 h, respectively. Typical apparent clearance of the bioavailable fraction (CL/F) was 0.795 L/h and was independent of animal weight. Considering the obtained pharmacokinetic parameters in our study, we may assume that effective parasite control in fallow deer is obtained using the usual recommended dose of 200 μg/kg.