英文医学课件：22 抗心绞痛药

1、Part 6 Antianginal Drugs抗心绞痛药,Organic nitrates receptor blockers Calcium channel blockers,Coronary vessels: blood supply for the heart,1. OVERVIEW,Coronary atherosclerosis: cause of cardiac ischemia,Distribution of coronary arteries in the heart,Ischemia (angina pectoris ): 心绞痛：心肌氧供需不平衡 imbalance be

2、tween oxygen demand and supply,Classification of angina pectoris 心绞痛类型: Exertional angina (劳累性心绞痛) Stable angina (稳定性心绞痛) Initial onset angina (初发型心绞痛) Accelerated angina (恶化性心绞痛) Spontaneous angina (自发性心绞痛) Angina decubitus (卧位型心绞痛) Variant or vasospastic angina (变异性痉挛性心绞痛) Acute coronary insuffici

3、ency (急性冠脉功能不全) Postinfarction angina (梗死后心绞痛) Mixed angina (混合性心绞痛) Unstable angina (不稳定性心绞痛): link of stable angina and myocardial infarction,1. OVERVIEW,不同类型心绞痛的发生,Myocardial oxygen demand is chiefly determined by: 心肌耗氧量因素： Contractility 收缩力 Heart rate 心率 Wall tension 室壁张力 Preload (venous return

4、) 前负荷（静脉回流量） Afterload (arteriolar resistance) 后负荷（动脉阻力）,1. OVERVIEW,preload,afterload,Myocardial oxygen demand is diminished by: 降低心肌耗氧量： Reducing contractility 收缩力 Reducing heart rate 心率 Reducing the preload 前负荷 Reducing the afterload 后负荷,1. OVERVIEW,Wall tension 室壁张力,1. OVERVIEW,Myocardial oxygen

5、 supply is chiefly determined by: 心肌供氧量： AV oxygen difference 氧分压 Regional myocardial distribution 局部血流分布 coronary blood flow: vascular resistance, artery pressure 血管阻力，动脉压,Effects of antianginal drugs 抗心绞痛药作用: Reducing oxygen demands 降低心肌耗氧量 Reducing heart rate and contractility Dilating systemic a

6、rteries and veins ( wall tension by lowering heart loads) Increasing oxygen supply 增加供血供氧 Dilating conduct coronary arteries ( coronary blood flow) Promoting regional distribution ( in ischemic regions) Others 其他: Anti-platelet coagulation and thrombus formation,1. OVERVIEW,2.1 Nitrates Nitroglyceri

7、n (硝酸甘油) A. Pharmacological actions 药理作用 Dilating vessels and reducing heart loads wall tension ; reflex tachycardia Redistribution of coronary circulation dilating conduct artery: collateral circulation reducing wall tension: blood flow in ischemic subendocardial area ,2. Antianginal drugs,Influenc

8、e of organic nitrates and dipyridamole on the blood supply of ischemic area,2. Antianginal drugs,Mechanism of the effect of nitroglycerin and other nitrates,Mechanism of the effect of nitroglycerin and other nitrates,B. Clinical uses 临床应用 Angina pectoris: all kinds, especially stable type Heart fail

9、ure：reducing heart loads due to vasodilation C. Adverse reactions 不良反应 Increase in heart rate and contractility 心率、收缩力 Symptoms due to vasodilation血管扩张引起: headache, flash, postural hypotension, collapse, ect. Others: methaemoglobinaemia（高铁血红蛋白） Tolerance 耐受性: avoiding steady-state plasma concentrati

10、on; supplement of agents containing SH (captopril),2. Antianginal drugs,2.1 Other nitrates 其他硝酸酯类 Isosorbide dinitrate (硝酸异山梨酯) Isosorbide-5-mononirate (5-硝酸异山梨酯) Compared with nitroglycerin 与硝酸甘油比较的特点: Orally active 口服有效 Similar but weaker effect 作用相似但较弱 Acting slowly but lasting longer 作用缓慢、持久 Lar

11、ger individual variation and more adverse effects 个体差异大，不良反应多见,2. Antianginal drugs,2.2 receptor blockers 受体阻断药 A. Pharmacological action 药理作用 Reducing oxygen demand: heart rate and contractility Increasing oxygen supply: diastolic period : perfusion time vascular tone in normal regions : blood flow

12、 in ischemic regions Others: Improving myocardial metabolism Inhibiting coagulation of platelets,2. Antianginal drugs,B. Clinical uses 临床应用 stable and unstable pectoris, especially associated with hypertension or arrhythmias, even with myocardial infarction; but not used for variant angina pectoris

13、C. Notes 注意点 Dose individualization: starting from small dose Withdraw gradually and slowly: symptom rebound Combination with nitroglycerin but without verapamil Contraindicated in heart depression, asthma, and so on,2. Antianginal drugs,2.3 Calcium channel blockers 钙拮抗剂,2. Antianginal drugs,2.3 Cal

14、cium channel blockers A. Pharmacological actions 药理作用 Reducing myocardial oxygen remand: heart loads : nifedipine heart rate and contractility : verapamil and diltiazem Increasing myocardial blood supply Protecting ischemic myocardial cells Inhibiting coagulation of platelets,2. Antianginal drugs,Ac

15、tions of calcium channel blockers,Selective calcium channel blockers Dihydropyridines (二氢吡啶类): nifedipine 硝苯地平 rapid, hypotension, reflex tachycardia amlodipine 氨氯地平 high bioavailability, t1/2 40-50 h, long-acting, less influences on heart rate and blood pressure Phenylalkylamines (苯烷胺类): verapamil

16、维拉帕米 reducing oxygen demands, antiarrhythmia Benzothiazepines (苯硫卓类): diltiazem 地尔硫卓 weaker for heart depression and vasodilation; suitable for variant angina pectoris,艹,艹,B. Clinical uses 临床应用 stable and variant type: nifedipine, verapamil, diltiazem unstable type: verapamil, diltiazem,2. Antiangin

17、al drugs,Actions of DHP (like nifedipine) are similar to those of nitroglycerin Actions of verapamil are similar to those of blockers Actions of diltiazem are intermedial in both above drugs,nitroglycerin blockers Ca2+ antagonists combination* Heart rate Contractility / Wall tension / / Oxygen deman

18、d Blood pressure : increase, : markedly increase; : decrease, : markedly decrease; : variable according to the dose and effect of each drug ; * blockers combined with nitroglycerin or Ca2+ antagonists (nifedipine; combination with verapamil/diltiazem not be recommendated) Caution: Combination may po

19、tentiate the antianginal effects, but may induce severe hypotension,3. Summary of antianginal drugs,2.4 Other drugs 其他药物 ACEIs （血管紧张素转化酶抑制药） Treating hypertension and preventing ischemic heart disease Reducing heart loads Inhibiting cardiac remodeling Nicorandil （尼可地尔） Opening ATP-sensitive K+ chann

20、el (KATP) Lowering intracellular Ca2+ Providing NO (like nitroglycerin) Inducing ischemic preconditioning,2. Antianginal drugs,Molsidomine （吗多明） Promoting collateral circulation Similar to nitroglycerin Used in stable angina Dipyridamole （双嘧达莫，潘生丁） Inhibiting adenosine uptake and cAMP degradation In

21、hibiting pletelet aggregation Small doses, long-term oral administration,2. Antianginal drugs,Summary,Cardiovascular pharmacology,Overview of Cardiovascular Diseases,Common Cardiac Diseases Abnormal contractility：Heart failures Abnormal rhythms：Arrhythmias Abnormal blood supply：Ischemic heart diseas

22、es Myocardial disorders Common vascular diseases Abnormal systematic resistance：Hypertension Dysfunction of coronary vessels：Coronary vascular diseases Dysfunction of cerebral vessels：Cerebral ischemia, hemorrhage Dysfunction of pulmonary vessels：Pulmonary hypertension Dysfunction of peripheral vessels: Peripheral vascular disorder Arteriosclerosis: basis of most CVS diseases,Overv