Question

The drug colestipol binds bile salts in the intestine forming complexes that cannot be absorbed. Explain how the binding of this drug affect absorption.

Answer 1

Cholesterol is the major, and most likely the only precursor of bile salts. Bile acids are secreted from liver and gallbladder into intestines during normal digestion and emulsify the fat and lipid materials of the food present there, in this way facilitating their absorption.

Colestipol binding with bile salts would prompt a reduction in the levels of serum cholesterol. Fats essentially require bile salts for their absorption. So, in case the bile salts are not absorbed, there will be a decrease in the absorption of cholesterol, triglycerides and fats. Furthermore, the body would need to supplant the bile salts that are being lost with the faeces. The resulting decline in cholesterol levels in the body will increase oxidation of cholesterol to bile acids on the grounds that bile salts are obtained from cholesterol.