Plasma concentrations of itraconazole following a single oral dose in juvenile California sea lions (Zalophus californianus).

Abstract

The objective of this study was to establish a single-dose pharmacokinetic profile for orally administered itraconazole in California sea lions (Zalophus californianus). Twenty healthy rehabilitated juvenile California sea lions were included in this study. Itraconazole capsules were administered orally with food at a target dose of 5-10mg/kg. Blood samples were collected from each animal at 0hr and attwo of the following timepoints: 0.5, 1, 2, 4, 6, 8, 12, 24, 48, and 72hr. Quantitative analysis of itraconazole in plasma samples was performed by high-performance liquid chromatography. An average maximum concentration of 0.22µg/ml±0.11 was detected 4hr after administration. The average concentration fell to 0.12µg/ml±0.11 by 6hr and 0.02µg/ml±0.02 at 12hr. At no point did concentrations reach 0.5µg/ml, the concentration commonly accepted for therapeutic efficacy. While this formulation was well tolerated by the sea lions, oral absorption was poor and highly variable among individuals. These data indicate that a single oral dose of itraconazole given as a capsule at 5-10mg/kg, under the conditions used in this study, does not achieve therapeutic plasma concentrations in California sea lions.