HMG-CoA reductase / NPC1L1

Class

Statin + ezetimibe fixed-dose combination

This combination pairs two agents that lower blood cholesterol through complementary pathways. Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in the liver's cholesterol synthesis pathway; blocking it reduces intracellular cholesterol, prompting liver cells to display more LDL receptors on their surface and clear more low-density lipoprotein (LDL, the primary carrier of 'bad' cholesterol) from the bloodstream. Ezetimibe acts elsewhere, in the intestinal wall, where it blocks NPC1L1, a transporter responsible for absorbing dietary and biliary cholesterol into the body. Reduced absorption similarly signals the liver to upregulate LDL receptors and pull more LDL from circulation. Used together, the two agents attack cholesterol regulation from both the production side and the absorption side, producing greater LDL reduction than either mechanism alone, often at a lower statin dose than would otherwise be needed to reach the same target. This matters because elevated LDL cholesterol is a well-established driver of atherosclerosis, the buildup of arterial plaque that underlies heart attack and stroke. Combination therapy is broadly relevant wherever aggressive LDL lowering is warranted, including in patients who do not reach cholesterol goals on a statin alone or who cannot tolerate higher statin doses.