35章氨基苷类与多黏菌素类-Jun Peng-4.ppt

第35章 氨基糖苷类与多黏菌素类 Aminoglycosides and polymyxins 彭 军 中南大学药理学系 第一节 氨基糖苷类抗生素 aminoglycosides 化学结构：氨基糖苷类抗生素的基本结构是由苷 元和氨基糖分子通过氧桥连接而成 Chemical structure: The basic structure of this group consists of aglycone and amino sugar molecule which are linked by oxygen bridge. 氨基糖 + 氨基环醇（苷元） 氨基糖苷 amino sugar +aminocycloalcohol (aglycon) aminoside 一、氨基糖苷类抗生素的共性Common characteristics of aminoglycoside antibiotics （一）化学结构相似 – similar chemical structure （二）体内过程相似- similar physiological disposition （三）抗菌谱相似 – similar antibacterial spectrum （四）抗菌机理相似-similar mechanisms of antibacteria （五）耐药性相似-similar drug resistance （六）不良反应相似-similar reverse effect （二）体内过程相似 Similar physiological disposition 1. 吸收：为有机强碱，口服难吸收，仅用于肠道感染 和肠道消毒。(高极性化合物) Absorption: it is the organic strong base and hard to be absorbed by oral. It is only used in intestinal infection and intestinal tract disinfection. 2. 分布：血浆蛋白结合率低，主要分布于细胞外液在耳淋巴液和肾皮质中, 浓度高可透过胎盘屏障，不易透过血脑屏障 Distribution: low ratio of binding with plasma protein. It is mainly distributed in extracellular fluid , ear lymph fluid and renal cortex. It is able to pass the placental barrier if concentration is high but it is unable to pass the blood-brain barrier. 3. 消除：不被代谢，原形肾小球滤过排泄，在肾小管无再吸收过程（奈替米星除外）, 尿中浓度高, 碱性尿中作用增强。 Elimination: it is not metabolized and is excreted by glomerular filtration as original form. The concentration in urine is high and alkaline urine could enhance its effect. （三）抗菌谱 - antibacterial spectrum 特点： 静止期杀菌剂，抗菌谱广characteristic: bactericide for rest period, broad 1、 G-菌 对需氧G-杆菌（包括酮氯假单孢菌）有强大的 杀灭作用； 对 G-球菌效差（如脑膜炎双球菌 、淋球菌无效） Strong bactericide for aerobic G- bacterial (pseudomonas aeruginosa), poorly effective to G- coccus (Diplococcus intracellularis, no effect to diplococcus gonorrho