title: The influence of gastrointestinal parasitism on fecal elimination of doramectin, in lambs.
abstract: A study was done to investigate the effect of parasitism on patterns of doramectin (DRM) fecal elimination in lambs. Fourteen Suffolk Down parasitized lambs (26.9 ± 1.5 kg body weight: bw) were purposely selected for the study. Seven pairs of lambs were allocated into two experimental groups. Group I (non-parasitized) was pre-treated with 3 repeated administrations of 5mg/kg bw of fenbendazole to maintain a non-parasitized condition. In Group II (parasitized), the lambs did not receive any anthelmintic treatment. After 85 d of the pre-treatment period, both groups were treated with a subcutaneous injection of 200 μg/kg bw of DRM. Fecal samples were collected at different times between -85 d before and 60 d after the DRM treatment, for both parasitological and chromatographic analysis. Samples were analyzed by high-performance liquid chromatography (HPLC) with fluorescence detection. Data of DRM concentrations were expressed as wet weight. A non-linear pharmacokinetic analysis was performed and results were compared using the Mann Whitney test. Fecal maximum concentrations (C(max)) of DRM were 1.37 ± 0.19 μg/g (parasitized group) and 0.86 ± 0.15 μg/g (non-parasitized group) observed at the time of the maximum concentration (T(max)) of 2.1 ± 0.4 and 3.1 ± 0.3d, respectively. Differences in C(max) values were significant (P<0.05). The accumulated elimination of DRM in feces, expressed as the percentage of DRM total dose, was 67.1% in the parasitized group, whereas in the non-parasitized group it was 56.5%. Our results showed that gastrointestinal parasitic diseases can modify the patterns of DRM fecal elimination, when the drug is administered by subcutaneous route in lambs.
authors.affiliation: Laboratorio de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Concepción, Campus Chillán, Chile. rubperez@udec.c
authors.forename: Rubén
authors.initials: R
authors.lastname: Pérez
authors.forename: Cristina
authors.initials: C
authors.lastname: Palma
authors.forename: Ignacio
authors.initials: I
authors.lastname: Cabezas
authors.forename: Luis
authors.initials: L
authors.lastname: Rubilar
authors.forename: Margarita
authors.initials: M
authors.lastname: Arboix
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002677:Chile; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005243:Feces / Q000469:parasitology*; D007279:Injections, Subcutaneous; D007411:Intestinal Diseases, Parasitic / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D007559:Ivermectin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics / Q000627:therapeutic use*; D010270:Parasite Egg Count; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000469:parasitology; D013997:Time Factors
chemical_list: D000871:Anthelmintics; D007559:Ivermectin; C084101:doramectin