Mechanism of action:
Questran is the brand name of the drug cholestyramine prescribed for
hypercholesterolemia. It is non-absorbable resin that binds to bile acids in intestines, facilitating their excretion in faeces. The increased faecal loss of bile acids leads to an increased oxidation of cholesterol to bile acids and a decrease in serum cholesterol level.
Side effect:
As cholestyramine is not absorbed, most of S/E are related to
gastro-intestinal. Constipation is common, but diarrhea, nausea & vomiting may also occur.
Caution:
Cholestyramine interferes with the absorption of fat-soluble vitamins, so supplements of vitamins A, D and K may be required for
prolonged treatment.
Also cholestyramine is capable of binding other drugs (e.g.
acetaminophen) to hinder their absorption,
other drugs should be taken at least 1 hour before or 4-6 hours after cholestyramine to reduce interference with absorption.