Bile-acid sequestrants

Colesevelam is a bile acid sequestrant. Bile acid sequestrants are ion exchange polymers that bind bile acids in the gut. Ion exchange polymers are insoluble organic polymers, which trap ions and in doing so release others [14]. There are four main types ... 

It is suggested that dietary fiber sequestrates bile acids decreasing the reabsorption of bile salts, increasing fecal excretion and reducing hyperlipidemia (37). 

Bile Acid Sequestrants. The bile acid binding resins, colestipol [26658424] and cholestyramine, ate also effective in controlling semm cholesterol levels (150). Cholestyramine, a polymer having mol wt > ICf, is an anion-exchange resin. It is not absorbed in the gastrointestinal tract, is not affected by digestive enzymes, and is taken orally after being suspended in water (151). 

Cliolestyramine (Questran) and colestipol (Colestid) are examples of bile acid sequestrants. Bile, which is manufactured and secreted by the liver and stored in the gallbladder, emulsifies fat and lipids as these products pass through the intestine Once emulsified, fats and lipids are readily absorbed in the intestine These drug bind to bile acids to form an insoluble substance that cannot be absorbed by the intestine, so it is secreted in the feces. With increased loss of bile acids, the liver uses cholesterol to manufacture more bile This is followed by a decrease in cholesterol levels. 

The bile acid sequestrants are used as adjunctive therapy for the reduction of elevated serum cholesterol in patients with hypercholesterolemia who do not have an... 

A common problem associated with the administration of the bile acid sequestrants is constipation. Constipation may be severe and may occasionally result in fecal impaction. Hemorrhoids may be aggravated. Additional adverse reactions include vitamin A and D deficiencies, bleeding tendencies (including gastrointestinal bleeding) caused by a depletion of vitamin K, nausea, abdominal pain, and distention. 

The bile acid sequestrants are contraindicated in patients with known hypersensitivity to the drugs. Bile acid sequestrants are also contraindicated in those with complete biliary obstruction. These drags are used cautiously in patients with a history of liver or kidney disease Bile acid sequestrants are used cautiously during pregnancy (Pregnancy Category C) and lactation (decreased absorption of vitamins may affect the infant). 

The HMG-CoA reductase inhibitors have an additive effect when used with the bile acid sequestrants, which may provide an added benefit in treating hypercholesterolemia that does not respond to a single-drug regimen. There is an increased risk of myopathy (disorders of the striated muscle) when the HMG-CoA reductase inhibitors are administered with erythromycin, niacin, or cyclosporin a When the HMG-CoA reductase inhibitors are administered with oral anticoagulants, there is an increased anticoagulant effect. 

Bile acid sequestrants may interfere with die digestion of fats and prevent die absorption of die fat-soluble vitamins (vitamins A, D, E, and K) and folic acid. When die bile acid sequestrants are used for long-term therapy, vitamins A and D may be given in a water-soluble form or administered parenterally. If bleedingtendencies occur as die result of vitamin K deficiency, parenteral vitamin K is administered for immediate treatment, and oral vitamin K is given for prevention of a deficiency in the futum... 

OILE ACID SEQUESTRANTS. Fhtients taking the antihyperlipidemic dragp, particularly the bile acid sequestrants, may experience constipation. The dragp can produce or severely worsen preexisting constipation. The nurse instructs the patient to increase fluid intake, eat foods high in dietary fiber, and exercise daily to help prevent constipation. If the problem persists or becomes... 

Older adults are particularly prone to constipation when taking the bile acid sequestrants The nurse should monitor older adults dosety for hard dry stools difficulty passing stools and any complaints of constipation. An accurate record of bowel movements must be kept. 

Explains possible need for vitamin A and D therapy and high-fiber foods if patient is receiving bile acid sequestrant. 

If fluvastatin or pravastatin is prescribed with a bile acid sequestrant, take fluvastatin 2 hours after die bile acid sequestrant and pravastatin at least 4 hours afterward. 

Which of the following adverse reactions is most common in a patient taking a bile acid sequestrant ... 

Cholestyramine, colestipol, and colesevelam are the bile acidbinding resins or sequestrants (BAS) currently available in the United States. Resins are highly charged molecules that bind to bile adds (which are produced from cholesterol) in the gut. The resin-bile acid complex is then excreted in the feces. The loss of bile causes a compensatory conversion of hepatic cholesterol to bile, reducing hepatocellular stores of cholesterol resulting in an up-regulation of LDL receptors to replenish hepatocellular stores which then result in a decrease in serum cholesterol. Resins have been shown to reduce CHD events in patients without CHD.26... 

Klausen IC, Gerdes LU, Meinertz H, Hansen FA, Faergeman O. Apolipopro-tein(a) polymorphism predicts the increase of Lp(a) by pravastatin in patients with familial hypercholesterolaemia treated with bile acid sequestration. Eur J Clin Invest 1993 23 240-245. 

The answer is a. (Hardman, pp 885-8870 Lovastatin should not be used in patients with severe liver disease. With routine use of lovastatin, serum transaminase values may rise, and in such patients the drug may be continued only with great caution. Lovastatin has also been associated with lenticular opacities, and slit-lamp studies should be done before and one year after the start of therapy There is no effect on the otic nerve. The drug is not toxic to the renal system, and reports of bone marrow depression are very rare There is a small incidence of myopathy, and levels of creatinine kinase should be measured when unexplained muscle pain occurs. Combination with cyclosporine or clofibrate has led to myopathy There is no danger in use with bile acid sequestrants. 

Dosingof selected agents by class fibrate (gemfibrozil 600 mg twice a day) niacin (1.5-3 g/day of immediate-release product) statin (simvastatin 10-40 mg/day if glomerular filtration rate [GFR] <30 mL/min, 20-80 mg/day if GFR >30 mL/min) bile acid sequestrant (cholestyramine 4-16 g/day). 

Alternative potential strategies for reduction of mucosal secondary bile acid exposure are to target deconjugation of glycine/taurine bile salts by bacterial bile salt hydrolases and/or bacterial 7-dehydroxylation of primary bile acids to secondary bile acids. Sequestration of bile acids in the intestinal lumen using probiotic bacteria has also been proposed as an area for future research. ... 

Other forms of possible treatment include bile acid sequestrants and UDCA. 

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