Effect of pantothenic acid on disposition kinetics and tissue residues of sulphadimidine in chickens.

Sulphadimidine was administered to chickens via the intracrop route to determine plasma concentrations of the unchanged sulphonamide and its acetylated derivatives, kinetic disposition, tissue residues and acetylation. The sulphadimidine was given alone (group 1) at a dose of 200 mg kg-1 bodyweight. Pantothenic acid was given via the intracrop route at a dose of 100 mg kg-1 bodyweight one hour before (group 2) and six hours after (group 3) sulphadimidine administration (200 mg kg-1 bodyweight intracrop). The highest plasma concentrations of sulphadimidine in groups 1, 2 and 3 were reached in 1.73, 1.62 and 1.71 hours, respectively, following intracrop administration. In birds of groups 1, 2 and 3 no sulphadimidine was detected at 72, 24 and 48 hours, respectively, following its administration. Estimation of sulphadimidine in most of the body tissues revealed that all tissues examined had lower concentrations than plasma. In chickens given pantothenic acid (groups 2 and 3) before and after sulphadimidine administration, an increase in the concentration of N4 acetylated derivatives of sulphadimidine was observed compared with birds given sulphadimidine alone (group 1).