Colestyramine is the name given to an absorption inhibitor. It is used to treat hypercholesterolemia.
What is colestyramine?
Colestyramine is a styrene, a colorless liquid that smells sweet. The active ingredient is used to treat diseases of fat metabolism. Colestyramine is a styrene, a colorless liquid with a sweet smell. The active ingredient is used to treat diseases of fat metabolism. As a water-insoluble macromolecule, colestyramine cannot be catalyzed by the body’s own enzymes and is not affected by metabolism. Colestyramine is used particularly when LDL cholesterol in the blood reaches too high a concentration. To treat this, the patient must first undergo a diet. If this does not lead to the hoped-for success, cholesterol-lowering agents such as statins are administered. If these also show no effect, colestyramine comes into play, which is combined with the statins. Only if the physician does not consider the use of statins to be helpful or if they are not well tolerated by the patient is colestyramine administered alone.
Pharmacologic effect
Colestyramine represents a resin that has the property of binding water. However, it is not water soluble. Since the active ingredient also cannot be digested, it passes through the intestine without changes. In the gastrointestinal tract, colestyramine ensures the targeted breakdown of bile acids. Colestyramine is actually a colestyramine chloride. For this reason, when it comes into contact with salts from the bile acids, the chloride is exchanged for the rest of the bile acid, resulting in the formation of common salt (sodium chloride). The production of bile acids takes place in the liver completely by cholesterol. During digestion, bile acids enter the intestine. However, the intestine recovers large portions of the bile acids and passes them on to the liver. Colestyramine, however, binds these bile acids, which in turn slows down their recirculation. This also has an effect on the liver, which begins to produce new bile acids due to the lack of them. In the process, the organ upregulates the enzyme cholesterol-7a-hydroxylase. Because the liver produces more bile acids as a result of this process, this leads to increased consumption of cholesterol. This now no longer appears in the blood. In this way, there is a drop in elevated LDL cholesterol levels.
Medical application and use
Colestyramine is used to treat hypercholesterolemia, in which excessive cholesterol levels occur within the blood. In addition, the drug is suitable for the treatment of diarrhea due to excess bile acids. Colestyramine can also be used to treat jaundice (icterus) and itching due to partial obstruction of the bile ducts. Colestyramine is also used as a diagnostic agent for chologenic diarrhea. If this is caused by surgery, the active ingredient is also used to treat the diarrhea. Another field of application is the interruption of the enteropathic circulation in the case of drug intoxication. Thus, colestyramine allows better elimination of drugs that depend on the enteropathic circulation. These include, among others, the drug digitoxin. The intake of colestyramine takes place in the form of chewable tablets, powders and granules, which are commercially available. In this process, the patient takes the colestyramine-containing drugs orally with plenty of water.
Risks and side effects
As with other medications, taking colestyramine may be associated with unpleasant side effects. However, these side effects do not show up in every patient. Thus, medicines are tolerated differently by people. The most common after colestyramine administration are constipation, bloating, loss of appetite, heartburn, nausea, vomiting, diarrhea and flatulence. Rarely, there may also be a reduced absorption of fat-soluble vitamins, a deficiency of folic acid in the blood, and an increase in fatty stools. In patients suffering from kidney dysfunction or in children with excess chlorine, there is a risk of hyperacidity of the organism. There are also some known contraindications to colestyramine.The drug must not be administered in cases of hypersensitivity to the drug, obstruction of the bile duct or intestinal obstruction (ileus). In pregnancy, too, colestyramine is considered only as a last resort when no other therapeutic options are available. The reason for this is the reduced absorption of important fat-soluble vitamins such as vitamins A, D, E and K, which can have a negative effect on the health of the child. During breastfeeding, the intake of colestyramine is considered safe, as the drug does not pass into breast milk. It is also possible to treat children and adolescents with the drug. The administration of colestyramine may also result in interactions with other drugs. There is a risk of reduced or delayed absorption of these preparations. These include primarily the diuretic hydrochlorothiazide, the antiepileptic phenobarbital, the anti-inflammatory phenylbutazone, thyroid hormones, and the antibiotics penicillin G and tetracycline. It is recommended that these agents not be taken until four hours after colestyramine.
