Diabetes and Lipid Clinic of Alaska



Bile acid resins

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.

Welchol (colesevelam), a type of resin, has been found to improve glucose control in diabetics as well. The exact mechanism of this is unknown.

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 other 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 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.

Potential side effects of bile acid resins

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. 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. 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 any of the following side effects:

  • Allergic reaction (sneezing, respiratory congestion, itching or skin rashes)
  • Severe abdominal pain with nausea and/or vomiting
  • Constipation  
  • Cough  
  • Dryness, hoarseness or sore throat  
  • Difficulty swallowing  
  • Muscle aches and pains  

Less serious potential side effects include:

  • Gas or belching
  • Abdominal bloating, upset and/or pain (not severe)
  • Heartburn, sour stomach or indigestion
  • Nausea and/or vomiting  
  • Dizziness or lightheadedness
  • Diarrhea  
  • Headache  

Drug or other interactions with bile acid resins

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 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. 

Lifestyle considerations with bile acid resins

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 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 in powder form. Colesevelam also comes in a 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. Once mixed, patients drink, 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.

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.

If you have any questions regarding the above information, please contact the medical professionals at the Diabetes and Lipid Clinic of Alaska.

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