May 26, 2010.  The U.S. Food and Drug Administration today advised consumers and health care professionals about potential rare occurrences of severe liver injury in patients taking the weight-loss medication orlistat, marketed as Xenical and Alli.

The FDA has approved a revised label for the prescription drug Xenical. The agency is working with the manufacturer of Alli on label revisions to reflect this rare occurrence.

Both Xenical and Alli are medications contain the same active ingredient, orlistat. Xenical, available only by prescription, contains 120 milligrams of orlistat. Alli, sold over-the-counter without a prescription, contains 60 mg of orlistat. An estimated 40 million people worldwide have taken either Xenical or Alli.

The FDA’s safety information and labeling changes are based on a review of cases of severe liver injury reported in individuals taking orlistat. The agency has identified 13 cases of severe liver injury, 12 of which were reports from outside of the United States. The only U.S. report of severe liver injury involved Alli. At this time, a cause-and-effect relationship of severe liver injury with orlistat use has not been established.

People who take Xenical or Alli should be aware that liver injury with orlistat – while rare – has been reported. Those taking the drug also should be aware of the signs and symptoms of liver injury, which include itching, yellow eyes or skin, dark urine, loss of appetite, or light-colored stools.

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm213470.htm