Ezetimibe helps control cholesterol

CHOLESTEROL was the cynosure of attention during the recently concluded Asian Pacific Society of Atherosclerosis and Vascular Diseases at the Iloilo Convention Center and was again a main focus at the annual meeting of the Philippine Society of Endocrinology and Metabolism held at the EDSA Shangri-La on March 22-24, 2018. Why all this fuss about cholesterol? Understandably, everybody, in fact, even school children, have this very negative attitude towards cholesterol and for good reasons. The word “cholesterol” has been associated a lot of diseases that led to many deaths especially from heart attack or a stroke. In the name of fairness, let’s take another look at cholesterol.

Cholesterol is a sterol- substance that has the complex cyclopentanoperhydroxyphenanthrene ring. Our own liver manufactures half to 2/3 of the total cholesterol in our body; the rest comes from our food. About 80% of the cholesterol made by the liver is used to make bile. Bile salts are needed for the absorption of fat-soluble vitamins like vitamin A, D, E and K. Moreover, cholesterol is a vital part of the cell membrane of the 75 trillion cells of the body. Without cholesterol, the women would not have their female hormones estrogen and progesterone and the reproductive organs of men would not reach full adult proportions because there is no male hormone testosterone, and so would the steroid hormones from the adrenal cortex.

Be that as it may, cholesterol, that is, if in excess, is a major contributor to atherosclerosis in which white blood cells, and monocyte migrate from the bloodstream into the wall of blood vessels, particularly arteries and are transformed into cells which accumulate fatty materials which in time lead to patchy thickening of the inner lining of the artery. Many complications arise from this, like loss of elasticity of the artery thus making it friable and brittle very susceptible to rupture. Aside from that, there would soon be significant narrowing of the lumen or opening of the affected artery thus compromising blood and oxygen supply to the cells of the organ involved like the heart-coronary thrombosis- or the brain- cerebral thrombosis.

Statins or vastatins have been the first line treatment of atherosclerosis. By inhibiting the enzyme HMG Co-A reductasehdroxymethylglutaryl Coenzyme A reductase- statins prevent the formation of excessive cholesterol from the food that we eat, mostly the saturated fats from animals like palmitic acid and stearic acid. However, clinical experience, scientific research and lots of studies and trials have shown that, the target level doctors would like to have, in order to prevent primary as well as secondary outcomes of the disease have not been encouraging and for the most part with dismal results. A comprehensive summary of trials using the different statins available in the market, at doses which are already high, have not yielded the expected ideal result.

Fortunately, there is Ezetimibe, a drug whose sterling properties and mechanism of action help in the significant reduction of levels of cholesterol in the blood. By inhibiting the absorption of ingested fat, Ezetimibe helps reduce the delivery of fatty substances into the bloodstream. In a landmark study of more than 18,144 patients , all post ACS-acute coronary syndrome- with LDL-C ( the bad cholesterol) of 50-125mg% or 50-100mg% with prior lipid lowering regimen. Half of the patients were randomized to Simvastatin 40 mg and the others were given the Ezetimibe-Simvastatin 10/40mg combination on top of standard medical/interventional therapy for at lest 2 and half years.. Primary outcome is composite of cardiovascular deaths, non-fatal myocardial infarction, stroke, hospitalization for unstable angina. The IMPROVE IT