Lassman H B, Coombes J D
Diagn Microbiol Infect Dis. 1984 Jun;2(3 Suppl):3S-12S.
Cefotaxime (CTX) sodium is a potent semisynthetic cephalosporin antibiotic that has an unusually broad spectrum of antibacterial activity. This paper discusses the metabolism of 14C-CTX in rats, dogs, and humans as well as in vitro studies in cells of rats and rabbits. Excretion of radioactivity was similar in the three species, with greater than 80% of the dose being recovered in urine. About one-third of the administered dose was eliminated unchanged. Desacetylcefotaxime. (des-CTX) was the major metabolite. Ordinarily, only the two products, both having antibacterial activity, were found in plasma. Also found in dog and human urine were two other metabolites, M2 and M3, both inactive. These metabolites were, however, found in the plasma and bile of nephrectomized rats. The metabolic pathway follows the route: CTX----des-CTX----des-CTX lactone----metabolites M2 and M3. All reactions probably occur in the liver. Differences in metabolism between the species are quantitative rather than qualitative.
头孢噻肟（CTX）钠是一种强效的半合成头孢菌素抗生素，具有异常广泛的抗菌活性谱。本文讨论了14C-CTX在大鼠、狗和人类中的代谢情况，以及在大鼠和兔子细胞中的体外研究。三种物种的放射性排泄情况相似，超过80%的剂量可在尿液中回收。约三分之一的给药剂量以原形排出。去乙酰头孢噻肟（des-CTX）是主要代谢产物。通常，血浆中仅发现两种具有抗菌活性的产物。在狗和人类尿液中还发现了另外两种无活性的代谢产物M2和M3。然而，在肾切除大鼠的血浆和胆汁中也发现了这些代谢产物。代谢途径如下：CTX→des-CTX→des-CTX内酯→代谢产物M2和M3。所有反应可能都发生在肝脏中。不同物种之间的代谢差异是定量的而非定性的。
