@article {Mitchell155, author = {A D Mitchell and G D Paulson and R G Zaylskie}, title = {Steady state kinetics of 14C-sulfamethazine [4-amino-N-(4,6-dimethyl-2-pyrimidinyl)benzene[U-14C]sulfonamide] metabolism in swine.}, volume = {14}, number = {2}, pages = {155--160}, year = {1986}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {Swine were dosed orally with 14C-sulfamethazine [4-amino-N-(4, 6-dimethyl-2-pyrimidinyl)benzene[U-14C]sulfonamide] for 3, 5, or 7 days (two 165-mg doses/day; 0.46 muCi/mg) and killed 8 hr after the last dose. The concentration of carbon-14 in the tissues increased by an average of 21\% from day 3 to day 5 of dosing. However, there was no further increase from day 5 to day 7, indicating that a steady state level of carbon-14 in the tissues was attained by dosing on 5 consecutive days. Liver, kidney, skeletal muscle, blood, and adipose tissue from all animals were analyzed for 14C-labeled sulfamethazine, N4-acetylsulfamethazine, desaminosulfamethazine [N-(4, 6-dimethyl-2-pyrimidinyl)benzenesulfonamide], and the N4-glucose conjugate of sulfamethazine. The identity of these compounds (the hydrolysis product of N4-glucose conjugate) was confirmed by HLPC and gas-liquid chromatography/mass spectral analysis after methylation. The relative distribution of 14C-sulfamethazine and these metabolites varied somewhat among the tissues analyzed but did not vary within a tissue after different periods of dosing.}, issn = {0090-9556}, URL = {https://dmd.aspetjournals.org/content/14/2/155}, eprint = {https://dmd.aspetjournals.org/content/14/2/155.full.pdf}, journal = {Drug Metabolism and Disposition} }