Cholesterol-reducing drugs are medications that lower the levels of fats (lipids) in the blood, including cholesterol and triglycerides. Besides lowering total cholesterol and LDL (“bad”) cholesterol levels, some cholesterol-lowering medications may also modestly increase levels of HDL (“good”) cholesterol. High LDL cholesterol levels and low HDL cholesterol levels are associated with heart attack, stroke and coronary artery disease.

Cholesterol-reducing drugs work on lipids in the bloodstream. Some work by reducing the amount of cholesterol or triglycerides produced or absorbed in the body. Others remove cholesterol that has built up in the arteries. The mechanisms and strengths of each type of cholesterol-reducing drug varies.

In general, cholesterol is a waxy type of fat that is produced naturally by the body and consumed in relatively modest amounts through the diet. Cholesterol is important because it is used as a building block for hormones, such as estrogen and testosterone. Cholesterol itself is carried through the bloodstream in a package known as a lipoprotein. Researchers have identified a number of different lipoproteins, each of which interacts with the body in a different way. High-density lipoproteins, or HDLs, are compact packages that can remove cholesterol from arteries, thus reducing the risk of heart attack and stroke. Other types of lipoproteins, including low-density lipoproteins (LDL), very low-density lipoproteins (VLDL) and intermediate density lipoproteins, are unstable packages that can deposit cholesterol into an artery, thus accelerating atherosclerosis and raising the risk of heart attack and stroke. triglycerides are another type of fat that are associated with increased cardiovascular risk.

The point of cholesterol-lowering medications is to favorably affect the lipid profile, or relative levels of HDL and LDL cholesterol in the bloodstream. Studies have shown that patients who have very high HDL levels experience a protective effect, while patients with elevated LDLs are at increased risk. Thus, cholesterol-lowering medications are routinely used to affect a person's coronary risk profile. They may be prescribed by people who have already experienced a heart attack or stroke, who have undergone a catheter-based therapy such as angioplasty with or without stenting, bypass surgery, or even patients who are at risk of dangerous arrhythmias.