What are the statin drugs : The statins are the most widely used medications today in lowering LDL cholesterol. Most of the clinical trials that showed heart attack reduction and improved longevity used one of the statins as the cholesterol lowering medication. Statins are well tolerated with low side effect rates when used long term. Statins not only lower blood LDL cholesterol levels, they also help increase HDL cholesterol levels. The statin medicines that are now on pharmacy shelves in the U.S. (putting the brand name first in capital letters followed by the generic name in parentheses) are: Lescol (fluvastatin sodium) made by Novartis Lipitor (atorvastatin calcium) made by Parke-Davis and Pfizer Mevacor (lovastatin) made by Merck Pravachol (pravastatin sodium) made by Bristol-Myers Squibb Zocor (simvastatin) made by Merck The statins act by repressing or inhibiting an enzyme called HMG-CoA reductase. The role of this enzyme is the promotion of a chemical reaction early in the synthesis of cholesterol. By inhibiting HMG-CoA reductase, the statins hinder the production (synthesis) of cholesterol by the liver. Diminished synthesis of cholesterol in the liver in turn stimulates (increases) the activity of LDL receptors on the surface of liver cells. Increasing LDL receptor activity decreases LDL cholesterol levels in blood. Studies have conclusively established that lowering LDL cholesterol with diet and statins reduces the risk of a second heart attack. The prevention of recurrent heart attacks in patients who have already suffered a heart attack is called secondary prevention. Studies have also demonstrated that reducing LDL cholesterol with diet and statins reduces the risk of having the first heart attack. Prevention of heart attacks in those who have never had a heart attack is called primary prevention. Studies have also confirmed that reducing LDL cholesterol benefits both men and women. For more information regarding the side effects, precautions, and drug interactions of the various statins, please read the Statins article, and visit the Medications area.

How can levels of HDL cholesterol be raised : The first step in increasing HDL cholesterol levels (and decreasing LDL/HDL ratios) is life style modification. When life style modifications are insufficient, medications are used. In prescribing medications or medication combinations, doctors have to take into account medication side effects as well as presence or absence of other abnormalities in cholesterol profiles. Regular aerobic exercise, loss of excess weight (fat), and cessation of cigarette smoking cigarettes will increase HDL cholesterol levels. Regular alcohol consumption (such as one drink a day) will also raise HDL cholesterol. However, there are different subclasses of HDL cholesterol which have varying degrees of effectiveness in preventing atherosclerosis. Alcohol is believed to increase the level of the less important subtype of HDL cholesterol. Because of other adverse health consequences of excessive alcohol consumption, alcohol is not recommended as a standard treatment for low HDL cholesterol. Medications that are effective in increasing HDL cholesterol include nicotinic acid (niacin), gemfibrozil (Lopid), estrogen, and to a lesser extent, the statin drugs (discussed below).

Cholesterol is a fatty substance (a lipid) that is an important part of the outer lining (membrane) of cells in the body of animals. Cholesterol is also found in the blood circulation of humans. The cholesterol in a person's blood originates from two major sources, dietary intake and liver production. Dietary cholesterol comes mainly from meat, poultry, fish, and dairy products. Organ meats, such as liver, are especially high in cholesterol content, while foods of plant origin contain no cholesterol. After a meal, cholesterol is absorbed by the intestines into the blood circulation and is then packaged inside a protein coat. This cholesterol-protein coat complex is called a chylomicron. The liver is capable of removing cholesterol from the blood circulation as well as manufacturing cholesterol and secreting cholesterol into the blood circulation. After a meal, the liver removes chylomicrons from the blood circulation. In between meals, the liver manufactures and secretes cholesterol back into the blood circulation.

"Statins" are a class of drugs that lowers the level of cholesterol in the blood by reducing the production of cholesterol by the liver. Statins block the enzyme in the liver that is responsible for making cholesterol. This enzyme is called hydroxy-methylglutaryl-coenzyme A reductase (HMG-CoA reductase for short). Scientifically, statins are called HMG-CoA reductase inhibitors. Cholesterol is critical to the normal function of every cell in the body. However, it also contributes to the development of atherosclerosis, a condition in which cholesterol-containing plaques form within the arteries. These plaques block the arteries and reduce the flow of blood to the tissues the arteries supply. When plaques rupture, a blood clot forms on the plaque, thereby further blocking the artery and reducing the flow of blood. When blood flow is reduced sufficiently in the arteries that supply blood to the heart, the result is angina (chest pain) or a heart attack. If the clot occurs on plaques in the brain, the result is a stroke. Clots occurring on plaques in the leg cause intermittent claudication (pain in the legs while walking). By reducing the production of cholesterol, statins are able to reduce the formation of new plaques and occasionally can reduce the size of plaques that already exist. In addition, through mechanisms that are not well understood, statins also stabilize plaques and make them less prone to rupturing and forming clots. Although the important role of cholesterol in atherosclerosis is widely accepted by scientists, research also shows that atherosclerosis is a complex process that involves more than just cholesterol. For example, scientists have discovered that inflammation in the walls of the arteries may be an important factor in atherosclerosis. New research shows that statins reduce inflammation, which could be another mechanism by which statins beneficially affect atherosclerosis. This reduction of inflammation does not depend on statins' ability to reduce cholesterol. Further, these anti-inflammatory effects can be seen as early as two weeks after starting statins.