Alli, Xenical: Time to ban weight-loss drugs?

(CBS/AP) Will the FDA pull the plug on two weight-loss pills? Health advocates have asked the agency to ban the fat-blockers Alli and Xenical, pointing to new reports linking the drugs to kidney stones and pancreatic damage.

Public Citizen petitioned the FDA Thursday to remove the drugs, saying it had identified 47 cases of acute pancreatitis and 73 of kidney stones among patients taking the drugs. The reports were culled from the FDA's public database of negative drug reactions.

GlaxoSmithKline's Alli is sold over the counter, while Roche's Xenical is available with a doctor's prescription. Sales of both versions have been declining for years.

Both drugs contain orlistat, which works by blocking the absorption of about one-quarter of any fat consumed. It's the only prescription weight-loss drug available for long-term use, though appetite-suppressing drugs like phentermine are available for short-term use.

Orlistat has never been popular, in part due to unpleasant side effects. Marketing materials for Alli stress the importance of keeping meals under 15 grams of fat to avoid loose, oily stools. Educational pamphlets even recommend people start the program when they have a few days off work, or to bring an extra pair of pants to the office.

Last year the FDA added warnings to Xenical and Alli about rare reports of liver damage.

In light of the drug's side effects and meager health benefit - patients typically lose about 3 percent of their weight after a year - Public Citizen says the drug should be yanked.

"Orlistat is a drug used to treat people who are either overweight or obese," states the petition. "Unfortunately, it has little clinical effectiveness and has the potential to damage a number of organs, including the liver, pancreas, and kidneys."

GlaxoSmithKline said in a statement that its drug is "the most studied weight loss medicine. Its safety has been established through 100 clinical studies involving more than 30 thousand patients."

A spokesman for Roche could not immediately provide comment Thursday morning.

Any U.S. citizen can file a petition with the FDA to ban a drug or medical device for safety issues. Most petitions are rejected, though Public Citizen has a rare track record of successful drug withdrawals. Last year, both the diet pill Meridia and painkiller Darvon were both withdrawn from the U.S. market, years after Public Citizen filed petitions against them.