Lipid altering agents encompass several classes of drugs that include HMG CoA reductase (hydroxymethylglutaryl CoA reductase) inhibitors or statins, fibric acid derivatives, bile acid sequestrants, cholesterol absorption inhibitors, and nicotinic acid. These drugs differ with respect to mechanism of action and to the degree and type of lipid lowering. Thus, the indications for a particular drug are influenced by the underlying lipid abnormality. Conventional dosing regimens and common adverse reactions are described in a table (table 1) and the range of expected changes in the lipid profile are listed in a separate table (table 2).
Lipid lowering, at least with statins, is beneficial in patients with dyslipidemias for both primary and secondary prevention of coronary heart disease. (See "Clinical trials of cholesterol lowering for primary prevention of coronary heart disease" and "Clinical trials of cholesterol lowering in patients with cardiovascular disease or diabetes".)
The mechanisms of benefit seen with lipid lowering are incompletely understood. Regression of atherosclerosis occurs in only a minority of patients; furthermore, clinical benefits of lipid lowering are seen in as little as six months, before significant regression could occur. Thus, other factors must contribute; these include plaque stabilization, reversal of endothelial dysfunction, and decreased thrombogenicity. (See "Mechanisms of benefit of lipid-lowering drugs in patients with coronary heart disease".)
The characteristics and efficacy of the statins will be reviewed here (table 3). Possible noncardiovascular benefits of statins are discussed separately. (See "Statins: Possible noncardiovascular benefits".) The efficacy of fibrates, lipid lowering drugs other than statins and fibrates, and diet and dietary supplements are also discussed separately. (See "Lipid lowering with fibric acid derivatives" and "Lipid lowering with drugs other than statins and fibrates" and "Lipid lowering with diet or dietary supplements".)
Development of muscle toxicity is a concern with the use of statins. This problem, including predisposing drug interactions, is discussed in detail separately. (See "Statin myopathy".)