Pharmacokinetics and metabolism of fenbendazole in channel catfish.

Fenbendazole (FBZ) was administered intravenously (1 mg/kg) and orally (5 mg/kg) to catheterized, confined channel catfish. Blood samples were collected for 72 h, and resulting FBZ plasma concentrations were pharmacokinetically modelled. Following intravenous administration t1/2α was 0.51 h, t1/2β was 16.8 h, body clearance (C1b) was 0.0598 L/kg/h, and Vd (area) was 1.45 L/kg. After oral administration the t1/2 (abs) was 1.47 h, the t1/2β was 20.1 h, and the tlag was 0.1 h.