Abstract
PHARMACOKINETICAL INTERACTIONS OF LINCOMYCIN AND AMPROLIUM IN BROILER CHICKENS

Pharmacokinetic parameters and bioavailability of lincomycin following a single intravenous and oral administrations were determined in broiler chickens. Effect of amprolium on the disposition kinetics and tissue residues of lincomycin following repeated oral administrations was also investigated. Following a single intravenous injection of lincomycin, 20 mg/kg.b.wt., in normal broiler chickens, plasma concentration-time curve was best described by a twocompartments open model with elimination half-life (t0.5 = 2.93±0.014 h), volume of distribution (Vdss = 1.76±0.014 L/kg) and total clearance of the drug (CLtot = 0.457±0.004 L/kg/h). Following a single oral administration, the maximum plasma concentration was 7.08±0.16 g/ml, reached at maximum time of 1.16±0.02 h. The mean systemic bioavailability following oral administration was 71.32± 2.62%. Following repeated oral administration in normal chickens, highest plasma concentration peaked after one hour of each oral dose. Amprolium resulted in a significant decrease in maximum plasma concentration (C max = 7.29 ± 0.204 g/ml) compared with lincomycin alone (C max = 8.13 ± 0.244 g/ml). Amprolium resulted in a significant decrease in tissue residues of lincomycin. It is concluded that the administration of amprolium before lincomycin in broiler chickens would altered the pharmacokinetic profile of lincomycin.