3)
clonic convulsions（阵挛性惊厥）
4)
（-）：coma (昏迷ure (呼吸衰竭)
2) Cardiovascular System: 心力↓，传导↓，心率↓，血压↓ force of contraction ↓, conduction rate↓, heart rate↓, blood pressure↓
【techniques of local anesthesia】(局麻方式)
1、 surface anesthesia（表面麻醉）：N末梢 2、 infiltration anesthesia（浸润麻醉）：N末梢 3、 conduction anesthesia（传导麻醉）：N干 4、 subarachnoid anesthesia（蛛网膜下腔麻醉）
酰胺：lidocaine 烷基胺：亲水性(hydrophilism)
（与H+结合后）
【mechanism of local anesthesia】
LA在细胞内侧阻断电压门控性钠通道 →阻断动作电位的产生和传导。
LAs block action potential generation by blocking voltage – gated Na+ channels.
spinal anesthesia (脊髓麻醉)或腰麻：脊N根 注意药液比重及病人的姿势。 5、 epidural anesthesia（硬膜外麻醉）：N根
【individuals of LAs】(常用药物)
Procaine(普鲁卡因): 穿透力差，不用于表面麻醉。 It penetrates(透过) mucous membranes too
2. Allergic reaction (变态反应): 酯类多见， Skin test should be made when procaine
is used.
A chemical search for synthetic(合成的) substitutes(代用品) for cocaine started in 1892. This resulted in 1905 in the synthesis of procaine(普鲁卡因), which is still useful local anesthetic.
Tetracaine (丁卡因) , ( 地卡因，dicaine)： It is too toxic to be used for filtration anesthesia.
【adverse reactions】
1. Absorption（吸收作用）
1) CNS: 先（+）后（-）
2)
（+）：restlessness(不安), tremor(震颤),
poorly, so it can not be used for surface anesthesia.
Lidocaine(利多卡因): 用于：1）各种局麻方式 ; 2）抗心律失常 It has a variety of clinical uses as a local anesthetic. In addition, it is used as an antiarrhythmic(抗心律失常的) agent.
【structure - activity relationship】(构效关系) The molecule（分子） of LA can be divided
into three main portions(部分):
芳香族环：疏水性(hydrophobicity)（亲脂性） 中间链： 酯：procaine
Chapter 14
局部麻醉药
Local anesthetics
The first local anesthetic to be discovered was cocaine (可卡因). Owing to its addiction(成 瘾), its clinical use was limited.