Ezetimibe: The First in a Novel Class of Selective Cholesterol-Absorption Inhibitors

Zetia (ezetimibe) is the first medication in the novel class of selective cholesterol-absorption inhibitors to be released in the United States. Ezetimibe selectively inhibits the uptake of cholesterol from the intestinal lumen at the level of the enterocyte in the intestinal brush border while having no effect on other sterols or lipid-soluble vitamins. Ezetimibe 10 mg daily produces a consistent reduction in low-density lipoprotein cholesterol (LDL-C) by approximately 15 to 20% when used as monotherapy or in combination with 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) or fenofibrate and a 4 to 9% increase in high-density lipoprotein cholesterol. Unlike other lipid-lowering medications that act in the gastrointestinal tract, ezetimibe does not appear to worsen hypertriglyceridemia. Ezetimibe also has an adverse-event profile that is similar to placebo when used as monotherapy or in combination with statins and fenofibrate. Studies of longer duration and with niacin, bile acid sequestrants, and gemfibrozil are warranted to more completely assess the safety of ezetimibe in combination therapy. To date, no clinically significant drug-drug interactions have been noted with the use of ezetimibe; however, further studies are warranted. Ezetimibe will be useful as monotherapy in patients who need modest reductions in LDL-C or are intolerant to other lipid-lowering medication, and in combination with a statin in patients who are unable to tolerate large doses of statins or need further reductions in LDL-C despite maximum doses of a statin. The long-term safety and the effect on cardiovascular morbidity and mortality of ezetimibe are unknown.