title: Effect of tick-borne fever on the disposition of sulphadimidine and its metabolites in plasma of goats.
abstract: The effect of tick-borne fever (TBF) on the plasma disposition of sulphadimidine (SDM) and its metabolites in goats was studied. In uninfected goats, SDM was extensively metabolised mainly by hydroxylation, glucuronidation and to a minor extent by acetylation. In TBF infected goats the hydroxylation of SDM into 6-methylhydroxysulphadimidine (SCH2OH) as well as into 5-hydroxysulphadimidine (SOH) was markedly reduced (-57.6 and -63.6 per cent, respectively). An unidentified metabolite (metabolite X) was detected, which was largely glucuronidated in the uninfected goats. In the TBF infected goats the glucuronide derivatives of the X metabolite and of SOH were barely detectable. In TBF infected goats the plasma concentration of the N4-acetylated metabolite (N4-SDM) was decreased to a lesser extent (-22.1 per cent) than the hydroxy metabolites. Due to the diminished metabolism the elimination half-life of SDM was increased 1.8 times and the total sulphonamide body clearance was diminished compared with findings in the control experiments.
mesh_terms: D000818:Animals; D004536:Ehrlichia; D005260:Female; D006041:Goats / Q000378:metabolism*; D007700:Kinetics; D012288:Rickettsiaceae Infections / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D013418:Sulfamethazine / Q000097:blood / Q000378:metabolism*
chemical_list: D013418:Sulfamethazine