Ivermectin Pharmacokinetics, Metabolism, and Tissue/Egg Residue Profiles in Laying Hens

MORENO, LAURA; DOMINGUEZ, PAULA; FARIAS, CRISTINA; CANTON, LUCILA; VIRKEL, GUILLERMO; MATÉ, LAURA; CEBALLOS, LAURA; LANUSSE, CARLOS; ALVAREZ, LUIS

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

AMER CHEMICAL SOC

Año: 2015 vol. 63 p. 10327 - 10332

0021-8561

The goals were to determine the ivermectin (IVM) plasma pharmacokinetics, tissue and egg residue profiles, and the in vitro metabolism in laying hens. Experiments conducted were: 1) Eight hens were intravenously treated with IVM and blood samples taken; 2) Eighty-eight hens were treated with IVM administered daily in water (5 days): forty were kept and their daily eggs collected; forty-eight were sacrificed in groups (n=8) at different times and tissue samples taken and analysed; 3) IVM biotransformation was studied in liver microsomes. Pharmacokinetic parameters were AUC 85.1 ng*day/mL; Vdss 4.43 L/kg and T½el 1.73 days. Low IVM tissue residues were quantified with the highest measured in liver and skin+fat. IVM residues were not found in egg white, but significant amounts were quantified in yolk. Residues measured in eggs were greater than some MRLs values, suggesting that a withdrawal period would be necessary for eggs after IVM use in laying hens.