The Drug Vytorin, a cholesterol-lowering combo made up of Merck's Zocor and Schering-Plough's Zetia, has won approval by the Food and Drug Administration. Like other statins, Zocor inhibits the production of cholesterol, while Zetia blocks the absorption of cholesterol. Combined, according to clinical trials done by Schering, they lower LDL cholesterol, on average, more than Zocor alone and more than Pfizer's Lipitor, a statin that is the world's best-selling drug. Vytorin is expected on drugstore shelves by mid-August.

The Hype Wall Street predicts an ad onslaught, not just because of tougher cholesterol-lowering guidelines recently set by the National Cholesterol Education Program. Analysts say Merck wants to boost Zocor profits before patent protection expires in 2006. Schering CEO Fred Hassan told investors in April that he expects Vytorin to drive recovery from the company's first-quarter losses.

Pity, then, that Zetia and Vytorin lack study results like those for Zocor, which has been proven to prevent heart attacks and death, says Eric Topol, chairman of cardiovascular medicine at the Cleveland Clinic. (However, lowering cholesterol by any means lowers risk.) Topol also worries that Zetia could hamper Zocor's ability to reduce heart inflammation, which may be a factor in heart attacks.

For you? Experts say Vytorin might be useful for someone already taking the two drugs separately or someone for whom a statin alone wasn't effective or caused such rare side effects as muscle weakness. "But no one size fits all when it comes to LDL-lowering," said Richard Karas, director of preventive cardiology at the New England Medical Center in Boston. Vytorin is expected to sell for about $70 per month. Insurers that cover the drug are expected to pay only about half the price. Possible side effects include headache and upper respiratory tract infection.

-- Francesca Lunzer Kritz