Bile acid resins are a type of cholesterol-reducing drug. Generally, these medications aim to lower the levels of fats (lipids) in the blood, including cholesterol and triglycerides. Some bile acid resins have been shown to reduce LDL (bad cholesterol) levels by 10 to 20 percent, while simultaneously raising HDL (good cholesterol) levels. High levels of LDL cholesterol, triglycerides and other fats in the bloodstream increase the risk of hardening of the arteries (atherosclerosis), heart attack, stroke and other heart-related conditions.

Bile acid resins may be prescribed in addition to other cholesterol-reducing medications to further reduce LDL levels. Other types of cholesterol reducing drugs include statins, fibrates and nicotinic acid.

Bile acids work by altering the chemistry of cholesterol processing. Under normal circumstances, the liver takes cholesterol out of the blood to make bile, which is used in the intestines during the digestive process. Most of this bile is eventually returned to the liver.  Bile acid resins block the recycling of bile acids in the intestine. To replace the lost bile acids, the liver is forced to remove more cholesterol from the blood to manufacture more bile. Bile acid resins are usually prescribed in powder form (which is mixed with liquid) or in a chewable bar.

Bile acid resins are not absorbed by the body. However, they may interfere with the absorption of some substances, including other medications and some vitamins. Patients are encouraged to inform their physicians of all other over-the-counter or prescription medications they may be taking before beginning bile acid resins therapy. In addition, patients may wish to ask their physicians about taking multivitamins or supplements to replace nutrients that the bile acid resins may prevent from being fully absorbed.

Certain types of bile acid resins (e.g., cholestyramine) are also used to lessen symptoms of patients with liver disease. These medications remove excess bile acids caused by disorders of the liver. The build-up of bile acids can cause symptoms such as severe itching.

Bile acid resins are a type of cholesterol-reducing drug. These medications lower the levels of fats (lipids) in the blood, including cholesterol and triglycerides. Some bile acid resins have been shown to reduce the level of LDL (“bad”) cholesterol between 10 and 20 percent, while simultaneously raising the level of HDL (“good”) cholesterol.

Bile acid resins may be prescribed in conjunction with other cholesterol-reducing medications, including statins, fibrates and nicotinic acid. All are commonly used to treat high cholesterol (hypercholesterolemia). When prescribed with other medications, bile acid resins have been shown to reduce LDL levels by as much as 50 percent. 

Bile acids work by altering the chemistry of cholesterol processing. Under normal circumstances, the liver takes cholesterol out of the blood to make bile, which is used in the in the intestines during the digestive process. Most bile is later returned to the liver and reused. Bile acid resins block the recycling of bile acids. To replace the lost bile acids, the liver is forced to remove more cholesterol from the blood to manufacture more bile. Bile acid resins are usually taken in powder form or in a chewable bar.

The most common bile acid resins are cholestyramine (brand names Questron and Questron Light) and colestipol (brand name Colestid). The cholesterol-lowering drug colesevelam (brand name WelChol) is often grouped with bile acid resins because it lowers cholesterol and triglyceride levels in a manner similar to bile acid resins.

Some bile acid resins are also used to lessen symptoms of patients with liver disease. Liver disease can cause a build-up of bile acids, resulting in symptoms such as severe itching or diarrhea, which may be treated with a bile acid resin (colestipol). In addition, cholestyramine and colestipol may be used to treat an overdose of the inotropic medication digitalis or for patients with too much of a substance called oxalate in their urine.

All types of cholesterol-lowering drugs are effective to some degree. However, statins are normally considered the first line of defense. Bile acid resins are not absorbed by the body, unlike statin and fibrates. They may be a more viable option for patients for whom other cholesterol-reducing medications are not recommended (e.g., pregnant women).

There are a number of side effects associated with bile acid resins. The most common of these is constipation, for which physicians will often prescribe a stool softener or laxative. Patients may be instructed to take stool softeners for a day or two before they begin taking bile acid resins. Patients may also experience stomach irritation or diarrhea upon starting bile acid resins.These symptoms often disappear after a few weeks, when the body has become more accustomed to the medication.

Patients should notify their physician immediately if they experience an allergic reaction, which can include sneezing, congestion, itching or skin rashes. In addition, specific drugs have been associated with the following side effects: 

Patients should consult their physician before taking any other medication (either prescription or over-the-counter) or nutritional supplements. Most medications should be taken at least one hour before or four to six hours after the resin. Bile acid resins may prevent other medications from working properly. Of particular concern to patients taking bile acid resins are:

• Anticoagulants. Medications that inhibit blood clot formation. Because certain bile acid resins (cholestyramine, colestipol) interfere with the effectiveness of some anticoagulants, physicians will often order routine blood tests to closely monitor coagulation.
  
  
• Inotropes. Medications that strengthen the heart’s contractions so that it can circulate more blood with fewer heartbeats.
  
  
• Diuretics. Medications that cause the kidneys to flush water and other substances (e.g., sodium) from the body through urine. 
  
  
• Certain antibiotics (e.g., penicillin G, tetracycline and the oral antibiotic vancomycin). Medications that kill or slow the growth of harmful microorganisms, such as bacteria (they have no effect on viruses). They are used to treat some infections and are given before medical/dental procedures to prevent infections in some patients. 
  
  
• Certain NSAIDs (nonsteroidal anti-inflammatory drugs. NSAIDs (e.g., phenylbutazone) are medications that are commonly used to reduce pain and inflammation. 
  
  
• Certain beta blockers (e.g., propranolol). Medications that reduce the workload of the heart and lower blood pressure. They are commonly used to treat high blood pressure, angina (a certain type of chest pain, pressure or discomfort associated with coronary artery disease) or heart failure. 
  
  
• Certain thyroid hormones. Thyroid hormones are substances important to the development or function of virtually all tissues and organs. People with low levels of thyroid hormones in their blood often take synthetic thyroid hormones to meet their body’s needs. 
  
  
• Grapefruit juice. Grapefruit juice interferes with the liver’s ability to break down (metabolize) some medications. This, in turn, can cause a toxic build-up of the medication in the blood. While the buildup is less likely if the juice is ingested four or more hours prior to the medicine, patients taking medications are advised to refrain from taking them with grapefruit juice. Patients may also be instructed to avoid eating grapefruit.

Patients should discuss with their physician the benefits and risks of taking bile acid resins if they have any of the following:

• Liver disease (history of disease or persistently high liver enzymes). Taking certain bile acid resins (colestipol) may result in an increase in cholesterol levels in patients with liver disease.
  
  
• Kidney disease. Cholestyramine and colestipol may increase the risk of developing electrolyte problems (blood disorders) in patients with kidney disease.

In addition, bile drug resins, cholestryamine and colestipol,  may worsen the following conditions:

• Gallstones
• Bleeding problems
• Stomach problems (e.g., heartburn, ulcers)
• Constipation and hemorrhoids
• Hypothyroidism (underactive thyroid gland)
• Phenylketonuria. A disorder that makes it difficult for the body to break down certain types of food. Certain bile acid resins (cholestyramine) are available in sugar–free form, which may contain phenylalanine, an ingredient in the artificial sweetener aspartame. Aspartame can cause problems in people with phenylketonuria. Patients with this condition may want to avoid sugar–free versions of bile acid resins.

Colesevelam may increase problems associated with severe gastrointestinal disorders, bowel obstruction, and swallowing problems. The drug may also increase the risk of post-surgical complications following major gastrointestinal surgery.

The most common side effect of bile acid resins is constipation. Some patients find that increasing their activity level (e.g., walking) eases this symptom. Patients are advised to consult with their physician about beginning an exercise program. Stool softeners or laxatives may also be prescribed.

In addition, these medications may inhibit the absorption of certain nutrients (vitamins A, D, K and folate). Patients are encouraged to talk to their physicians about taking additional supplements and/or adding green leafy vegetables and skim milk to their diets.

Bile acid resins are usually administered in a chewable bar or in powder form, except colesevelam, which is usually in pill form. Powdered medication should never be taken in dry form because it could cause choking.

If a powder is prescribed, it should be mixed thoroughly in two ounces of any beverage except grapefruit juice. Once mixed, patients drink the medication, fill the glass again with more liquid and then drink that as well. This process ensures that none of the medication is left in the glass. Not all bile acid resins will completely dissolve. The powder may also be mixed with milk in hot or regular breakfast cereals, in thin soups (e.g., tomato or chicken), or with some pulpy fruits (e.g., crushed pineapple, peaches, pears or fruit cocktail).

Patients should carefully follow the directions for taking their medication provided by their physician and pharmacy. Those who miss a dose of this medication should take it as soon as possible, unless it is nearly time for the next dose. In that case, the missed dose should be skipped. Double doses of this medication should NOT be taken.

Bile acid resins may be less effective in people who are significantly overweight. Therefore, in addition to lifestyle changes recommended to reduce blood fat levels, patients may be placed on a weight loss program. In many cases, the lifestyle changes needed to manage blood fats will be similar to those in a weight loss program (e.g., diet, exercise, stress management).

All patients taking bile acid resins should inform their physician immediately of any side effects or concerns. Patients should not abruptly stop taking their medications without first consulting their physicians. It is also important that patients notify all physicians (including dentists) that they are taking bile acid resins before undergoing any surgical procedure.

Most patients on medication to treat high cholesterol (hypercholesterolemia) will take it for the rest of their lives, provided no serious side effects occur. Patients should remember that medications may control high cholesterol, but they do not cure it. Even if all their symptoms are relieved, patients should continue to take their medication exactly as directed, eat a heart-healthy diet that is low in saturated fats and keep all scheduled follow-up appointments with their physician.

The use of bile acid resins in pregnant women has not been studied. In animal studies, these substances have not been found to cause birth defects. Since bile acid resins are not absorbed by the body, they are unlikely to cause problems with pregnant or breast-feeding mothers or their children. These medications may inhibit the absorption of certain nutrients (vitamins A, D, K and folate) that a pregnant mother, fetus or nursing infant need – even when vitamin supplements are taken. Patients are encouraged to discuss the use of bile acid resins with their physicians, including their obstetrician-gynecologist.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their condition. Patients may wish to ask their doctor the following questions related to bile acid resins:

1. Should I use bile acid resins to lower my cholesterol levels?
   
   
2. Which type of bile acid resin drug is best for me?
   
   
3. Do I have any conditions that indicate I should not use bile acid resins?
   
   
4. What other drugs may help lower my cholesterol and triglyceride levels?
   
   
5. Can I take bile acid resins with other cholesterol-lowering drugs?
   
   
6. Will supplements or diet changes work instead of this medication?
   
   
7. Are there advantages to bile acid resins in comparison with other medications?
   
   
8. Will bile acid resins affect other medications I use?
   
   
9. How long will I need to be on this medication?
   
   
10. When can I expect to see a change after starting bile acid resins?
    
    
11. What diets or nutrition supplements can I use with this medication?
    
    
12. What can I take to lower the side effects from bile acid resins?