Question

QUESTION 12 Using relevant clinical examples, describe how each of the following helps to lower blood cholesterol: (1) bile acid sequesterants (2) HMG-CoA reductase inhibitors

Answer 1

Bile acid sequestrant

work by exchanging chloride ions for bile acids. by this, they bind bile acids and sequester them from the enterohepatic circulation. The liver in turn produces more bile acids to replace those that was lost. As the body uses cholesterol to make bile acids, this decreases the level of LDL cholesterol in the blood. For eg. Cholestyramine, Colestipol and Colesevelam

Hmg CoA reductase inhibitor act by competitively inhibiting HMG-CoA reductase, a enzyme of the mevalonate pathway. As statins are similar in structure to HMG-CoA , they fit into the enzyme's active site and compete with the native substrate ie HMG-CoA. It reduces the rate by which HMG-CoA reductase is able to produce mevalonate, the next molecule in the process  that Ultimately produces cholesterol.example: atorvastatin, fluvastatin and lovastatin etc