ayer A.G., the German pharmaceutical and chemical conglomerate, voluntarily withdrew Baycol, its highly profitable cholesterol-lowering drug, from the world market yesterday. Thirty-one patients have died while taking it, the company reported, because the drug caused an unusual condition in which muscle tissue broke down.
The United States Food and Drug Administration "agrees with and supports this decision," the agency said. It said pharmacists would be instructed to return the drug to Bayer for refunds. The F.D.A. approved Baycol for use in the United States in 1997.
Though other drugs in its class, called statins, have been linked to muscle cell damage in rare cases, the problem is much more common with Baycol than with other such drugs, said Dr. John Jenkins, the director of the office of drug evaluation at the F.D.A.
Statins are wildly popular drugs taken by millions of Americans. They make cholesterol levels plummet by blocking an enzyme required in its synthesis. Since the first statins were introduced in the late 1980's, they have revolutionized the treatment of high cholesterol levels.
From the beginning, medical experts said, statins were known to cause the muscle problem, rhabdomyolysis, which can lead to kidney failure and other problems. But it occurred very rarely and was almost never fatal. Dr. Scott Grundy of the University of Texas Southwestern Medical Center in Dallas said that as far as he knew, there was not a single death from rhabdomyolysis in clinical trials where 50,000 patients were carefully studied.
With Baycol, however, reports of serious rhabdomyolysis were about 10 times as frequent as with the other statins, Dr. Jenkins said.
"Baycol really stood out as being different," he said. "Baycol did not offer any benefits beyond those of the other statins. But it carried a potential risk, and that leads to a conclusion that it is no longer safe to be marketed."
The Baycol deaths tended to occur in patients taking higher doses of the drug and in those taking it along with gemfibrozil, a nonstatin drug that also lowers blood triglycerides.
Dr. Jenkins said patients taking Baycol should consult with their doctors about taking another drug instead. Any patients taking Baycol and experiencing muscle pain, or taking Baycol along with gemfibrozil, should immediately stop taking Baycol and consult with their doctors, he added.
Bayer said it was withdrawing the medicine from markets throughout the world except for Japan, where gemfibrozil is not available. The company said using the two drugs together was "contraindicated," meaning that doctors were not supposed to prescribe both.
Dr. Claude Lenfant, director of the National Heart, Lung and Blood Institute, said two of his own children were taking statins. If they asked him if they should stop, he said, "I would say no."
The problems with Baycol may prove devastating for Bayer, and the company's withdrawal of its drug shocked investors. Bayer predicted that the loss of Baycol would reduce its revenues this year by as much as $572 million.
Last year, the drug generated $554 million in sales and Bayer had predicted that sales would top $800 million this year. The drug's biggest competitors are two older statins, Lipitor from Pfizer and Zocor from Merck, which together account for about 80 percent of sales in anti cholesterol drugs.
Bayer's position in the global pharmaceutical industry was already shaky. Bayer is one of the last old- style conglomerates trying to be major competitors in both the pharmaceutical and chemical industries. Most of its big rivals, from DuPont in the United States to BASF and Aventis in Europe, have chosen to focus on one industry and sell the other. Bayer's pharmaceutical business is far smaller than the industry leaders'.
The withdrawal of Baycol was the latest in a string of problems that leave Bayer with few promising new drugs on the market and even fewer in the pipeline for the next few years. Several weeks ago, the Food and Drug Administration ordered Bayer to shut down production of Kogenate, a fast-growing medication for hemophilia, because of contamination problems, and the company halted clinical trials for what it had billed as a major new asthma drug.
"Bayer is now very, very weak in comparison to other pharmaceutical companies," said Martin Roediger, a pharmaceutical analyst at DG Bank in Frankfurt, which lowered its rating for Bayer shares to "sell" from "reduce."
Bayer's shares plunged nearly 17 percent yesterday, dropping 7.4 euros to 37.41 euros in Frankfurt.