1、Chapter 27 Lipid-lowering drugs and anti-atherosclerotic drugs 【 Learning points】 Atherosclerosis is the main pathological basis of cardiovascular and cerebrovascular diseases. The etiology and pathology of atherosclerosis are complex. This chapter mainly introduces lipid-lowering drugs, antioxidant
2、s, polyene fatty acids, and arterial endothelial-protecting drugs. （ 一 ） Lipid-lowering drugs Hyperlipoproteinemia, that is, plasma VLDL, IDL, LDL, and apoB concentrations higher than normal, or HDL, apoA concentrations lower than normal, are prone to atherosclerosis and are risk factors for atheros
3、clerosis. Lipid-lowering drugs include the following four categories: (1) MG-CoA reductase inhibitor Commonly used are mevastatin, lovastatin, pravastatin, simvastatin, fluvastatin and so on. 【 Pharmacological action】 Competitively inhibits HMG-CoA reductase, thereby blocking the conversion of HMG-C
4、oA to methyldihydroxyvalerate, reducing the synthesis of cholesterol in the liver, and subsequently increasing the synthesis of LDL receptors, and ingesting LDL and IDL in the plasma into the liver. Clearance increases, thereby lowering plasma LDL and IDL, and VLDL can also be reduced. 【 Clinical ap
5、plication】 It is effective for primary hypercholesterolemia, heterozygous familial and nonfamilial hypercholesterolemia, type III hyperlipoproteinemia, and diabetic and renal hyperlipidemia. (2) Bile acid binding resin It is not absorbed by the intestine after oral administration, and forms a comple
6、x with bile acid to be excreted with feces, blocking the reabsorption of bile acid. Representative drugs include cholestyramine and colestipol. It can obviously reduce the plasma TC and LDL-C concentration, and slightly increase the HDL-C concentration, and is commonly used in a and b and familial h
7、eterozygous hyperlipoproteinemia. (3) Bate Clofibrate is no longer used due to adverse reactions. Gefibezi, fenofibrate, bezafibrate, etc. are currently used. 【 Pharmacological action】 Increase the activity of lipoprotein lipase (LPL), thereby increasing the decomposition of CM and VLDL; at the same
8、 time, it can reduce the synthesis of VLDL in the liver; VLDL decomposition increases, reducing the exchange of cholesterol between VLDL and HDL, making HDL-C slightly increased. 【 Clinical application】 This class of drugs mainly reduce TG, VLDL, IDL, and are used for type b, , hyperlipoproteinemia.
9、 (4) Niacin Niacin is a water-soluble vitamin. By inhibiting the formation of cAMP, the activity of triglyceride is reduced, and the concentration of triglyceride in plasma is rapidly reduced. VLDL synthesis is reduced, and LDL and IDL are reduced. It is a broad-spectrum lipid-lowering drug, which i
10、s effective for type , , , hyperlipidemia, and can also be used for myocardial infarction. (5) Antioxidants Probucol mainly reduces the production of LPO by blocking lipid peroxidation, thereby relieving a series of processes of atherosclerotic lesions. Used for various types of hypercholesterolemia
11、. Vitamin C and Vitamin E also have a certain antioxidant effect. (6) Polyene fatty acids The mechanism of lowering blood lipid of fish oil preparations is not yet clear, and may be related to the inhibition of liver synthesis of VLDL. Fish oil preparations only slightly reduce triglycerides and slightly increase HDL-C, but have no effect on total cholesterol and LDL-C. Mainly suitable for mild hypertriglyceridemia. (7) Mucopolysaccharides and polysaccharides
