Biochem/Physiol Actions | Ezetimibe is in a class of lipid-lowering compounds that selectively inhibits the intestinal absorption of cholesterol and related phytosterols. Ezetimibe, administered alone is indicated as adjunctive therapy to diet for the reduction of elevated total-C, LDL-C, and Apo B in patients with primary (heterozygous familial and non-familial) hypercholesterolemia. It is also used in combination therapy with HMG-CoA reductase inhibitors. Ezetimibe has a mechanism of action that differs from those of other classes of cholesterol-reducing compounds (HMG-CoA reductase inhibitors, bile acid sequestrants, fibric acid derivatives, and plant stanols). Ezetimibe does not inhibit cholesterol synthesis in the liver, or increase bile acid excretion but instead localizes and appears to act at the brush border of the small intestine and inhibits the absorption of cholesterol, leading to a decrease in the delivery of intestinal cholesterol to the liver. This causes a reduction of hepatic cholesterol stores and an increase in clearance of cholesterol from the blood; this distinct mechanism is complementary to that of HMG-CoA reductase inhibitors. Ezetimibe is an azetidinone derivative and a cholesterol absorption inhibitor with lipid-lowering activity. Ezetimibe appears to interact physically with cholesterol transporters at the brush border of the small intestine and inhibits the intestinal absorption of cholesterol and related phytosterols. As a result, ezetimibe causes a decrease in the level of blood cholesterol or an increase in the clearance of cholesterol from the bloodstream. Overall, the following effects observed are a reduction of hepatic cholesterol stores and a reduction of total cholesterol, LDL cholesterol, and other triglycerides in the blood. |
