中医中药药理学外文版 (8).pdf

Chapter 29 drugs acting on the blood and hematopoietic organs 【Learning points】一一.Anticoagulant (一一)Heparin【Pharmacological effects】1.Anticoagulant effect:(1)The anticoagulant mechanism:Combines with antithrombin in the blood to enhance the inactivation effect of antithrombin on thrombin and coagulation factors.(2)Anticoagulant features:oral invalid,need intravenous injection and subcutaneous injection;anticoagulant effect both in vivo and in vitro;the effect is strong and quick,and the duration is short.2.Enables vascular endothelium to release lipoprotein esterase,hydrolyzes chylomicrons and VLDL in the blood to regulate blood lipid.3.Inhibit the activity of inflammatory mediators and inflammatory cells,showing anti-inflammatory effects 4.Inhibit the proliferation of vascular smooth muscle cells 5.Inhibit platelet adhesion and aggregation【Clinical application】Prevent deep vein thrombosis,pulmonary embolism and other thromboembolic diseases,prevent thrombosis and expansion;Prevent early stage of disseminated intravascular coagulation;Prevention and treatment of myocardial infarction,cerebral infarction,cardiovascular surgery and thrombosis after peripheral vein surgery;Cardiovascular surgery,cardiac catheterization,hemodialysis and other anticoagulation in vitro.【Adverse reactions】Excessive application can easily cause spontaneous bleeding,which can be rescued by injecting protamine.(二二)Coumarins Coumarins are oral anticoagulants.Commonly used drugs are bis-coumarin,warfarin,acetocoumarin(new anticoagulant).【Pharmacological effects】Vitamin K competitive antagonist,inhibits the conversion of vitamin K from epoxidized type to hydroquinone type in the liver,prevents the repeated use of vitamin K,and inhibits the activation of coagulation factors II,and X.【Clinical application】It is used orally to prevent and treat thromboembolic diseases;it is used in combination with antiplatelet drugs to reduce major surgical operations,rheumatic heart disease,and artificial heart valve replacement to prevent venous thrombosis.【Adverse reactions】Overdose is easy to cause spontaneous bleeding,a special antagonist:VitK.【Drug interactions】1.Drugs that reduce its anticoagulant effects include:phenobarbital,phenytoin and other liver drug enzyme inducers.2.The drugs that enhance its anticoagulant effects are:(1)Drugs that can replace its combination with plasma proteins:bute,indomethacin,and acetylsalicylic acid.(2)Drugs that inhibit intestinal VitK synthesis:broad-spectrum antibiotics.二二.Fibrinolytic drugs and fibrinolytic inhibitors(1)Fibrinolytic drugs:It breaks plasminogen into plasmin to promote fibrinolysis and dissolve thrombus.It is used to treat acute thromboembolic diseases such as acute myocardial infarction and cerebral infarction.But it has no effect on old blood clots.Commonly used drugs are streptokinase,urokinase,aniprase,recombinant staphylokinase,tissue-type plasminogen activator.Streptokinase:combined with plasminogen to form SK-plasminogen complex,which promotes the conversion of plasminogen into plasmin and dissolves thrombus.May cause allergies.Urokinase:direct activation of plasminogen into plasmin.No antigenicity,incidence of allergic reactions.(2)Fibrinolysis inhibitors:aminotoluic acid,tranexamic acid,etc.Inhibit plasminogen activator,thereby inhibiting the formation of plasmin,so that fibrin can not be dissolved and hemostasis.It is suitable for hemorrhage with increased fibrinolytic activity such as late DIC,postpartum hemorrhage,and bleeding after surgery such as lung,liver,pancreas,and prostate.Excessive dosage can cause thrombosis and induce myocardial infarction.三三Antiplatelet agents(一一)Drugs that inhibit platelet metabolism 1.Cyclooxygenase inhibitor:aspirin【Mechanism of action】In small doses,cyclooxygenase in platelets was inhibited,TXA2 synthesis was reduced,and platelet aggregation was inhibited to prevent thrombosis.【Clinical application】Thromboembolic disease caused by hyperplatelets;Ischemic heart disease(acute myocardial infarction,unstable angina);Cerebral ischemia.2.TXA2 synthase inhibitor and TXA2 receptor blocker:lidogray It is a powerful TXA2 synthase inhibitor and has TXA2 receptor antagonism.It has a strong effect on platelet thrombosis and coronary artery thrombosis,and can significantly reduce the incidence of re-embolism,repeated angina pectoris and ischemic stroke.3.Phosphodiesterase inhibitor:dipyridamole Inhibit PDE,increase Camp concentration;enhance PGI2 activity;activate adenylate cyclase;inhibit platelet cyclooxygenase,reduce TXA2 synthesis;promote PGI2 production in vascular endothelial cells.It is mainly used to prevent thromboembolic diseases and prevent platelet thrombosis after heart valve replacement。（二二）Drugs that inhibit ADP-mediated platelet activation Ticlopidine:interferes with ADP-mediated platelet activation,inhibits platelet membrane glycoprotein GPb/a receptor allosteric and fibrinogen recognition site exposure,thereby inhibiting the combination of platelets and fibrinogen to produce antiplatelet aggregation effect.Mainly used to prevent stroke,myocardial infarction and recurrence of peripheral arterial thrombotic diseases.(三三)Thrombin inhibiting drugs Hirudin:a powerful and specific thrombin inhibitor that can be used to prevent postoperative thrombosis,hemodialysis and cardiopulmonary bypass.(四四)The platelet membrane glycoproteins GP b/a receptor antagonist Acyclovir doses:competitive platelet membrane glycoproteins GP b/a receptor.It is mainly used for the treatment of acute myocardial infarction and unstable angina pectoris.四四.Coagulant agents Vitamin K Vitamin K as carboxylase coenzyme involved in the liver synthesis of clotting factor,used in vitamin K deficiency bleeding,and jaundice,biliary fistula,chronic diarrhea,and application of VitK antagonists,such as coumarin.Or used in hemorrhage caused by VitK deficiency caused by long-term use of broad-spectrum antibiotics.五五.Anti-anemia drugs(一)Iron Oral preparations include ferrous sulfate,ferric ammonium citrate,and iron dextran.Used to treat iron deficiency anemia.Factors affecting iron absorption are:stomach acid,VitC,fructose,cysteine,etc.promote iron absorption;high phosphorus,high calcium,tannic acid(which can precipitate iron),tetracycline(complex with iron)hinder iron absorption.(二)Folic acid and VitB12 Folic acid is reduced to 5-methyltetrahydrofolate in the body,and then enters the cell as a methyl donor to turn VitB12 into methyl VitB12,which itself becomes tetrahydrofolate,as a one-carbon unit carrier,involved in the synthesis of nucleic acids and proteins.Folic acid and VitB12 jointly promote the growth and maturation of red blood cells,clinically used to treat megaloblastic anemia.Anemia caused by folic acid antagonist requires calcium tetrahydrofolate.VitB12 deficiency will affect normal nerve myelin sheath lipid synthesis and neurological symptoms.The absorption of VitB12 requires the participation of internal factors.Therefore,the lack of internal factors caused by atrophic gastritis can affect its absorption,cause pernicious anemia,and neurological diseases such as neuritis and atrophy;VitB12 must be injected.六六.Hematopoietic growth factor The role and clinical application of erythropoietin EPO,G-CSF filgrastim,GM-CSF sagrastim.七七.Blood volume expander The pharmacological effects and clinical application of dextran;the functional characteristics and adverse reactions of medium,low and small molecular weight dextran.