Nursing Pharmacology Chapter 11: Drugs Used in Treating Hyperlipidemia
Pharmacological Management of Hyperlipidemia
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Human plasma lipids are transported as protein complexes (lipoproteins)
Abnormally high levels of any lipoproteins species called:
Hyperlipoproteinemias
Hyperlipidemias
Hyperlipemia (refers to elevated triglyceride levels only)
Hyperlipidemias: Major clinical consequences
> 50% of coronary heart disease (CHD) in United States is due to abnormal lipoprotein and plasma lipid levels/metabolism
Usually elevated lipoprotein inpatients with CHD results from (in the context of some degree of genetic predisposition):
Excess body weight
Sedentary lifestyle
Diets high in saturated and total fat
Acute pancreatitis (associate with hyperlipidemia)
Lipoprotein: Classification: based on densities -- 5 classes:
Chylomicrons
Very low-density lipoproteins VLDL
Intermediate density lipoproteins IDL
Low-density lipoproteins LDL
High-density lipoproteins HDL
Plasma proteins in atherogenesis
Two forms of Apo B: apolipoprotein responsible for cholesterol transported to artery wall
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Components involve foam cells (macrophages and smooth muscle cells, filled with cholesteryl esters)
Factors promoting atherosclerosis development:
Lipoprotein glycation (associated poorly controlled diabetes) promotes foam cell development
Arterial hypertension
Blood pressure control may be useful in prevention stroke/and coronary artery disease
Atheromatous plaque properties
Growth over time (increased foam cell number; collagen and fibrin accumulation)
Lesion calcification may occur
Symptoms due to coronary artery disease may occur abruptly-- sequence:
Endothelial cell rupture over active plaques
Then platelet activation followed by:
Thrombus formation (occlusive thrombosis)
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High-density lipoproteins (HDL) and atherogenesis
Antiantherogenic characteristics:
Remove cholesterol from artery wall
Reduce atherogenic lipoprotein oxidation
Low HDL levels: independent CHD risk factor
Atherogenic lipoprotein impairment of coronary arteriole dilation (mediated by nitric oxide)
Cigarette smoking and Coronary Heart Disease:
Risk factor for CHD
Associated with:
Decreased HDL levels
Less effective cholesterol retrieval
Endothelial cytotoxicity
Enhanced atherogenic lipoproteins oxidation
Increased thrombogenesis
Primary Reference: Malloy, M. J, and Kane, J. P., Agents Used in Hyperlipidemia, in Basic and Clinical Pharmacology, (Katzung, B. G., ed) Appleton-Lange, 1998, pp 563-577.
Primary Reference: Ginsberg, H. N and Goldberg, I. J. Disorders of Intermediary Metabolism: Disorders of Lipoprotein Metabolism, In Harrison's Principles of Internal Medicine 14th edition, (Isselbacher, K.J., Braunwald, E., Wilson, J.D., Martin, J.B., Fauci, A.S. and Kasper, D.L., eds) McGraw-Hill, Inc (Health Professions Division), 1998, pp 2138-2149.