Disposition kinetics of albendazole and metabolites in laying hens

BISTOLETTI, M.; ALVAREZ, L.; LANUESSE, C.; MORENO, L.

JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012

0140-7783

An increasing prevalence of roundworm parasites in poultry, particularly in litter-based housing systems, has been reported. However, few anthelmintic drugs are commercially available for use in avian production systems. The anthelmintic efficacy of albendazole (ABZ) in poultry has been demonstrated well. The goal of the current work was to characterize the ABZ and metabolites plasma disposition kinetics after treatment by different administration routes in laying hens. Twenty four laying hens Plymouth Rock Barrada were distributed into three groups and treated with ABZ as follow: intravenously at 10 mg/kg (ABZ iv); orally at the same dose (ABZ oral); and in medicated feed at 10 mg/kg/day for seven days (ABZ feed). Blood samples were taken up to 48 hours post-treatment (ABZ iv and ABZ oral) and up to 10 days post-start feed medication (ABZ feed). The collected plasma samples were analyzed by high-performance liquid chromatography. ABZ and its ABZSO and ABZSO2 metabolites were recovered in plasma after ABZ iv administration. ABZ parent compound showed an initial concentration of 16.4 ± 2.0 mg/mL, being rapidly metabolized into the ABZSO and ABZSO2 metabolites. The ABZSO maximum concentration (Cmax) (3.10 ± 0.78 µg/mL) was higher than ABZSO2 Cmax (0.34 ± 0.05 µg/mL). The area under the concentration vs time curve (AUC) for ABZSO (21.9 ± 3.6 µg·h/mL) was higher than that observed for ABZSO2 and ABZ (7.80 ± 1.02 and 12.0 ± 1.6 µg·h/mL, respectively). The ABZ body clearance (Cl) was 0.88 ± 0.11 L/h/kg with an elimination half-life (T1/2el) of 3.47 ± 0.73 h. The T1/2el for ABZSO and ABZSO2 were 6.36 ± 1.50 and 5.40 ± 1.90 h. After ABZ oral administration, low ABZ plasma concentrations were measured between 0.5 and 3 h post-treatment. ABZ was rapidly metabolized to ABZSO (Cmax: 1.71 ± 0.62 µg/mL) and ABZSO2 (Cmax: 0.43 ± 0.04 µg/mL). The metabolite systemic exposure (AUC) values were 18.6 ± 2.0 and 10.6 ± 0.9 µg·h/mL for ABZSO and ABZSO2, respectively. The half-life values after ABZ oral were similar (5.91 ± 0.60 and 5.57 ± 1.19 h for ABZSO and ABZSO2, respectively) to those obtained after ABZ iv administration. ABZ was not recovered from the bloodstream after ABZ feed administration. AUC values of ABZSO and ABZSO2 were 61.9 and 92.4 µg·h/mL, respectively. The work reported here provides useful information on the pharmacokinetic behaviour of ABZ after both iv and oral administrations in hens, which is a useful first step to evaluate its potential as an anthelmintic tool for use in poultry.