Wise R
Department of Medical Microbiology, Dudley Road Hospital, Birmingham, UK.
J Antimicrob Chemother. 1990 Dec;26 Suppl E:13-20. doi: 10.1093/jac/26.suppl_e.13.
The pharmacokinetics of the older and more recent oral cephalosporins are reviewed. With the exception of cefadroxil the older agents (cephalexin, cephradine and cefaclor) have serum elimination half-lives of less than or equal to 1 h and hence have to be administered three to four times daily. The urinary recovery of these agents is high (greater than 80% of oral dose) with the exception of cefaclor (54%). Cefaclor is also chemically unstable. The newer agents can be divided into those that are prodrugs (cefpodoxime proxetil and cefuroxime axetil) and compounds that are absorbed as such (cefixime, cefprozil and ceftibuten). They all have half-lives greater than 1.25 h and can be given once or twice daily. The penetration of these agents into an inflammatory exudate was studied and found to be cefixime 132%, ceftibuten 113%, cefpodoxime 104%, cefuroxime 92% and cefprozil 79% of the serum concentration. The penetration of cefpodoxime and cefixime into the respiratory tract was also studied; the mean percentage bronchial mucosal penetration was 52% for the former and 38% for cefixime. The urinary recovery of these newer agents (with the exception of ceftibuten) tends to be less than that of the earlier agents. There was a relationship between the serum elimination half-life of these agents and the degree of tissue penetration, those agents with longer half-lives penetrating to a greater extent.
本文综述了早期和近期口服头孢菌素的药代动力学。除头孢羟氨苄外，早期的药物（头孢氨苄、头孢拉定和头孢克洛）血清消除半衰期小于或等于1小时，因此必须每日给药三至四次。除头孢克洛（54%）外，这些药物的尿回收率很高（大于口服剂量的80%）。头孢克洛化学性质也不稳定。较新的药物可分为前体药物（头孢泊肟酯和头孢呋辛酯）和直接吸收的化合物（头孢克肟、头孢丙烯和头孢布烯）。它们的半衰期均大于1.25小时，可每日给药一次或两次。研究了这些药物在炎性渗出液中的渗透情况，发现头孢克肟为血清浓度的132%，头孢布烯为113%，头孢泊肟为104%，头孢呋辛为92%，头孢丙烯为79%。还研究了头孢泊肟和头孢克肟在呼吸道中的渗透情况；前者支气管黏膜平均渗透百分比为52%，头孢克肟为38%。这些较新药物（除头孢布烯外）尿液回收率往往低于早期药物。这些药物的血清消除半衰期与组织渗透程度之间存在关联，半衰期较长的药物渗透程度更高。
