FDA weighing two diet drugs' fates this week

CHICAGO — There has never been a magic prescription to help millions of obese Americans lose weight. Whether one is any closer to reality is now under scrutiny.

A Food and Drug Administration advisory panel will decide today whether the diet drug Meridia will remain on the market amid calls that it be removed. And on Thursday, another drug, known as lorcaserin, is up before an advisory committee where its developer will face questions from panelists and a possible recommendation for agency approval.

With estimates by the U.S. Centers for Disease Control and Prevention that 2 in 3 Americans are overweight and 1 in 3 are obese, the drug market is hungry for an effective diet pill.

But the idea has proved difficult to pull off.

There has not been a prescription pill for weight loss approved in more than a decade, since 1999 when Xenical, which works by blocking the absorption of fat, was approved. And though the FDA gave a version of Xenical known as Alli the go-ahead to be sold over the counter, its gastrointestinal side effects such as diarrhea have kept many consumers from taking it for long periods, doctors say.

Neither Xenical nor Meridia has been a big seller, and Meridia sales have deteriorated amid criticism of its heart risks. Meridia's maker, Abbott Laboratories, says it no longer promotes the drug in the U.S., where its sales are projected this year to be $30 million.

"Those of us who are in this business are pretty concerned as well as frustrated that there are not more treatments," said Robert Kushner, medical director of the Northwestern University Comprehensive Center on Obesity.

"Americans are spending millions, if not billions of dollars, on supplements and other products that have no benefit, so clearly there is a need for prescription drugs," he said. "Diet and exercise are not effective for everyone who is overweight."

Prescription diet pills have had trouble winning respect with consumers and doctors because of safety issues and side effects. In particular, the diet drug combination known as fen-phen was a disaster for the drug industry when it was linked to heart valve damage and subsequently yanked from pharmacy shelves in 1997.

Meridia has been attacked by doctors and consumer groups based on studies that show increased risks of heart attacks and strokes.