How Does Zetia Work?

Zetia is the brand name of the drug ezetimibe. Zetia is the first drug of its kind. Unlike the statins, which block the synthesis of cholesterol in the liver, or the bile-acid sequestrants, which bind to cholesterol-rich bile in the intestines, Zetia lowers cholesterol by blocking the absorption of dietary cholesterol by the digestive tract.

Function

Cholesterol is an important part of cell membranes, hormones and bile. Cholesterol not only enters the body through the foods we eat, but it is also manufactured in the liver. Cholesterol is one of the main components of bile. Bile aids digestion by breaking down fats in the intestines. Once the bile has been used, it is carried back to the liver and recycled.
Zetia binds to a molecule that helps carry the cholesterol through the wall of the intestine into the bloodstream. This causes the cholesterol to pass through the digestive system and out with the feces. It mainly blocks the absorption of the cholesterol that is eaten, but also affects the cholesterol in the bile. This prevents the cholesterol in the bile from being recycled, and forces the liver to pull more cholesterol out of the bloodstream for use in the manufacture of more bile.
Researchers also believe that Zetia stimulates the cell membranes to take in more LDL, or "bad" cholesterol, into the cell. All these work together to lower the amount of cholesterol that circulates in the bloodstream.

Effects

Even though Zetia causes more cholesterol to pass through the system, it does not affect the levels of fat-soluble vitamins like vitamin E and vitamin D. Zetia works differently from the statin drugs, which block the manufacture of cholesterol by the liver. Since it works differently, Zetia and a statin can be taken together by people whose cholesterol is not lowered enough by statin drugs alone. The prescription drug Vytorin is a combination drug that contains Zetia and the statin simvastatin in one tablet.
Zetia typically lowers LDL cholesterol levels by 18 percent. When Zetia is added to the drug regimen of someone taking a statin, it can decrease cholesterol as much as 25 percent more than with just the statin drug.

Side Effects

The most common side effect of Zetia is stomach upset and diarrhea. People taking Zetia also may experience tiredness and joint pain. Notify your doctor if you experience muscle pain while taking Zetia or any other cholesterol-lowering drug.