Bile Acid Sequestrants or Resins are drugs used prevent bile acid absorption in the intestines in order to lower the cholesterol levels in the long run.
Two commonly used Bile Acid Sequestrants are Cholestyramine and CoestipoI. These are basic ion exchange resins supplied in the chloride form. They are neither digested nor absorbed in the gut. The Bile Acid Sequestrants bind bile acids in the intestine interrupting their enterohepatic circulation. Faecal excretion of bile salts and CH (which is absorbed with the help of bile salts) is increased. This indirectly leads to enhanced hepatic metabolism of CR to bile acids. More LDL receptors are expressed on liver cells: clearance of plasma IDL, LDL and indirectly that of VLDL is increased.
Bile Acid Sequestrants have been shown to retard atherosclerosis, but are not popular clinically because they are unpalatable, inconvenient, have to be taken in large doses, cause flatulence and other g.i. symptoms, interfere with absorption of many drugs and have poor patient acceptability.