Dose-dependent systemic exposure of albendazole metabolites in lambs

ALVAREZ, L.; SUAREZ, G.; CEBALLOS, L.; MORENO, L.; LANUSSE, C.

JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 35 p. 365 - 372

0140-7783

The gastrointestinal absorption of most drugs follows a first-order kinetics, whereby a constant fraction of the total drug is absorbed in each equal time interval. Although this related absorption principle is applicable to the most of the therapeutically used drugs, it remains unclear for poorly water soluble compounds such as the benzimidazole anthelmintics in ruminants. The goal of the current work was to characterize the albendazole (ABZ) metabolites plasma disposition kinetics after ABZ administration at different dose rates to nematode-infected lambs. Eighteen (18) Corriedale lambs artificially infected with a resistant Haemonchus contortus strain were allocated into 3 groups and intraruminally treated with ABZ at either 5 (ABZ5), 15 (ABZ15) or 45 (ABZ45) mg/kg. Blood samples were collected up to 120 h post-treatment and the obtained plasma was analyzed by HPLC. The estimated pharmacokinetic parameters were statistically compared using parametric and non-parametric tests. None of the animals involved in the current trial showed any adverse events during the study. While ABZ parent drug was not recovered in the bloodstream, the area under the concentration vs time curve (AUC) of the active ABZ-sulphoxide (ABZSO) metabolite increased significantly (P