title: The influence of Ostertagia circumcincta and Trichostrongylus colubriformis infections on the pharmacokinetics of febantel in lambs.
abstract: Plasma concentrations of febantel and its major metabolites fenbendazole, oxfendazole and oxfendazole sulphone were determined after oral administration of 7.5 mg/kg febantel in lambs before and 28 days after infection with 50,000 L3 larvae of Ostertagia circumcincta or Trichostrongylus colubriformis. The febantel concentrations were always very low and only in a few samples higher than the detection limit. The mean decrease in AUC for the three metabolites for the infected sheep in comparison to the parasite naïve sheep was 13.9% +/- 4.1% (mean +/- SEM) and 23.7% +/- 5.3% in the O. circumcincta infected and the T. colubriformis infected lambs respectively. This reduction was only significant for the T. colubriformis infected group. In order to determine a more complete pharmacokinetic profile, febantel was injected intravenously at a dose of 2.5 mg/kg in a further study.
authors.affiliation: Laboratory of Veterinary Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Gent, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Debackere
authors.forename: J
authors.initials: J
authors.lastname: Landuyt
authors.forename: J
authors.initials: J
authors.lastname: Vercruysse
authors.forename: Q
authors.initials: Q
authors.lastname: McKellar
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000871:Anthelmintics / Q000493:pharmacokinetics*; D001562:Benzimidazoles / Q000493:pharmacokinetics; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D005273:Fenbendazole / Q000493:pharmacokinetics; D006146:Guanidines / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D008297:Male; D010029:Ostertagiasis / Q000378:metabolism / Q000662:veterinary*; D010270:Parasite Egg Count / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000378:metabolism* / Q000469:parasitology; D014253:Trichostrongylosis / Q000378:metabolism / Q000662:veterinary*
chemical_list: D000871:Anthelmintics; D001562:Benzimidazoles; D006146:Guanidines; D005273:Fenbendazole; C011030:oxfendazole; C017309:febantel