Three million people worldwide are taking the new, heavily advertised anti-cholesterol drugs Zetia and Vytorin, despite a lack of clinical evidence that they reduce cardiovascular disease or heart attacks, or help patients live longer. Vytorin and Zetia brought in $5.2 billion last year for Merck and Schering-Plough, placing them among the best-selling drugs in the world. The Food and Drug Administration approves many drugs based on whether they perform a specific action, like lowering cholesterol, without requiring long-term trials on whether they extend life or lower disease risks. Other FDA-approved drugs have been found to be ineffective or even dangerous. A possible link between Vytorin and cancer cannot be proved or ruled out after three studies, reports AP. In 1999, the FDA approved the diabetes drug Avandia, because it lowered blood sugar; it was later found to increase heart attacks. But pharmaceutical companies oppose changing the current system. Ken Johnson, senior vice president of the Pharmaceutical Research and Manufacturers of America, says the FDA's approach enables patients "to access life-saving and life-enhancing remedies more quickly."