Atorvastatin cholesterol-lowering drug, molecular model. Atorvastatin, marketed by Pfizer as Lipitor, was the best-selling drug in the world in 2004. It inhibits an enzyme responsible for the production of cholesterol in the liver, thus reducing the amount of cholesterol in the blood. As cholesterol production slows, liver cells take up low density lipoprotein (LDL) cholesterol from the blood. High blood levels of LDL (often called bad") cholesterol lead to atherosclerosis, causing increased blood pressure and heart disease. This is one of the biggest killers in the developed world. Atoms are colour-coded: carbon (blue), oxygen (orange), nitrogen (purple), fluorine (green) and hydrogen (white)."