Diet drugs Alli and Xenical may cause liver failure

Users of Alli and Xenical, beware -- the diet drugs may cause liver failure, according to the U.S. Food and Drug Administration. In a statement released on May 26, the government agency said, "There is a potential, rare occurrence of liver failure in people who take the weight-loss medications Alli or Xenical."

The warning was issued after the FDA reviewed 12 overseas cases of liver damage caused by the prescription drug Xenical and one U.S. case involving the over-the-counter Alli. Of those cases, two died from liver failure while three required liver transplants.

At the same time, the FDA acknowledged that it could not find a cause-and-effect relationship between the active ingredient orlistat and the liver damage, since other factors or drugs may have contributed. As a result, a new label was approved for Xenical, and the FDA is working with GlaxoSmithKline to revise Alli's label.

Xenical was FDA approved in 1999, while Alli, which retails for about $45, was cleared for over-the-counter use in 2007. Some 40 million people have used the drugs worldwide.

The warning is standard fare, John Gever, senior editor of MedPageToday.com, told WalletPop in a telephone interview, "It's not clear the liver injuries were caused by the drugs. Still, the FDA always errs on the side of caution. Putting warnings on labels is an easy thing to do."