Disposition of sulfonamides in food-producing animals: pharmacokinetics of sulfathiazole in swine.

Disposition of sulfathiazole in plasma and urine of swine was determined following single intravenous and oral doses. Pharmacokinetics of the drug were described by a 1-compartment open model. The drug was rapidly eliminated, mainly by renal excretion of unchanged sulfathiazole and metabolism to acetylsulfathiazole, with a biological half-life of 1.4 hours. Sulfathiazole (in solution) was absorbed rapidly (half-life 0.8 hour) and relatively completely (73%) following oral administration.