Disposition of sulfonamides in food-producing animals V: Disposition of sulfathiazole in tissue, urine, and plasma of sheep following intravenous administration.

The plasma, urine, and tissue sulfathiazole concentrations were determined at various times following intravenous administration to 12 sheep. The plasma and urine data were consistent with a one-compartment pharmacokinetic model, with an elimination half-life of 1.1 hr and a volume of distribution of 0.39 liter/kg. Sulfathiazole was eliminated by excretion of unchanged drug in urine (67%) and by formation of two metabolites. The data obtained from eight tissue sites were consistent with the one-compartment pharmacokinetic model presented and confirmed that tissue residues of sulfathiazole can be calculated from serum and urine drug concentration.