Cholesterol-reducing drugs

Encyclopedia of Medicine, Apr 06, 2001 by Nancy Ross-Flanigan

Cholesterol-reducing drugs are medicines that lower the amount of cholesterol (a fatlike substance) in the blood.

Cholesterol is a chemical that can do both good and harm in the body. On the good side, cholesterol plays important roles in the structure of cells and in the production of hormones. But too much cholesterol in the blood can lead to heart and blood vessel disease. To complicate matters, not all cholesterol contributes to heart and blood vessel problems. One type, called high density lipoprotein (HDL) cholesterol, or "good cholesterol," actually lowers the risk of these problems. The other type, low density lipoprotein (LDL) cholesterol, or "bad cholesterol," is the type that threatens people's health. The names reflect the way cholesterol moves through the body. To travel through the bloodstream, cholesterol must attach itself to a protein. The combination of a protein and a fatty substance like cholesterol is called a lipoprotein.

Many factors may contribute to the fact that some people have higher cholesterol levels than others. A diet high in certain types of fats is one factor. Medical problems such as poorly controlled diabetes, an underactive thyroid gland, an overactive pituitary gland, liver disease or kidney failure also may cause high cholesterol levels. And some people have inherited disorders that prevent their bodies from properly using and eliminating fats. This allows cholesterol to build up in the blood.

Treatment for high cholesterol levels usually begins with changes in habits. By losing weight, stopping smoking, exercising more and reducing the amount of fat and cholesterol in the diet, many people can bring their cholesterol levels down to acceptable levels. However, some may need to use cholesterol-reducing drugs to reduce their risk of health problems.

Different types of cholesterol-reducing drugs work in different ways. Not all cholesterol comes from the diet -- some is made in the body. So the strategy of some drugs is to prevent the body from making cholesterol. Other cholesterol-reducing drugs interfere with the body's ability to absorb cholesterol from food. A third approach involves drugs that combine with cholesterol and remove it from the bloodstream.

Examples of cholesterol-reducing drugs are cholestyramine (Questran), colestipol (Colestid), gemfibrozil (Lopid), lovastatin (Mevacor), pravastatin (Pravachol) and simvastatin (Zocor). Lovastatin, pravastatin and simvastatin belong to a group of medicines called HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitors. These drugs prevent the body from making cholesterol by blocking a key enzyme in the process.

The recommended dosage depends on the type of cholesterol-reducing drug. Check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage.

Always take cholesterol-reducing drugs exactly as directed. Try not to miss any doses, but do not take double doses to make up for a missed dose. Never take more medicine than the physician ordered.

Physicians may tell some patients to take a combination of cholesterol-reducing drugs, such as pravastatin and colestipol. Following the directions for how and when to take the drugs is very important. The medicine may not work properly if both drugs are taken at the same time of day.

Do not stop taking this medicine without first checking with the physician who prescribed it. Cholesterol levels may increase when the medicine is stopped, and the physician may prescribe a special diet to make this less likely.

Seeing a physician regularly while taking cholesterol-reducing drugs is important. The physician will check to make sure the medicine is working as it should and will decide whether it is still needed. Blood tests and other medical tests may be ordered to help the physician monitor the drug's effectiveness and check for side effects.

For most people, cholesterol-reducing drugs are just one part of a whole program for lowering cholesterol levels. Other important parts of the program may include weight loss, exercise, special diets and changes in other habits. The medicine should never been viewed as a substitute for other measures the physician has ordered. Remember that cholesterol-reducing drugs will not cure problems that cause high cholesterol; they will only help control cholesterol levels.

People over 60 years of age may be unusually sensitive to the effects of some cholesterol-reducing drugs. This may increase the chance of side effects.

Anyone who is taking an HMG-CoA reductase inhibitor should be sure to tell the health care professional in charge before having any surgical or dental procedures or receiving emergency treatment.

People who have certain medical conditions or who are taking certain other medicines may have problems if they take cholesterol-reducing drugs. Before taking these drugs, be sure to let the physician know about any of these conditions:

Anyone who has had unusual reactions to cholesterol-reducing drugs in the past should let his or her physician know before taking the drugs again. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.