Pharmacokineticscomma; Metabolismcomma; and Renal Excretion of Sulfadimidine and Its N4-Acetyl and Hydroxy Metabolites in Humans

摘要

Summary:Sulfadimidine is acetylated and hydroxylated in humans. The hydroxylation pathways account for 10ndash;20percnt; of the dose, leaving the acetylation as the major metabolic pathway. The hydroxylation pathways are independent of the acetylator phenotype. The plasma concentration-time curve of sulfadimidine in fast acetylators is biphasic, with half-lives of 1.7 and 5.4 h, whereas that in slow acetylators is monophasic, with a half-life of 7.6 h. Hydroxylation of a methyl group in sulfadimidine lowers the protein binding from 90 to 60percnt;, while acetylation does not affect the protein binding. Methyl hydroxylation markedly increases the renal clearance.