Xenical, Alli Side Effects Being Reviewed by FDA for Potential Liver Injury

The FDA issued an early communication Monday about an ongoing safety review of potential liver side effects of Alli and Xenical, two weight-loss drugs that contain orlistat. Reports of liver injury among users of oslistat drugs are being reviewed to determine if there is a direct relationship between the liver damage and Alli or Xenical.

The review comes after the FDA received at least 32 reports of liver injury among individuals taking weight loss drugs like Alli or Xenical.

Xenical (orlistat 120mg) is a prescription medication that was approved by the FDA in 1999. The lower dose Alli (orlistat 6mg) is an over-the-counter weight-loss drug that was approved in 2007. Both drugs are marketed by GlaxoSmithKline, PLC, though Xenical is manufactured by Roche.

The medications are intended for use together with a reduced-calorie diet. They work by preventing the absorption of fats, thereby reducing caloric intake.

In 2008, Xenical generated sales of $30 million and Alli generated sales of $131 million during its first full year on the market.

Among the reports of serious liver injury with the use of orlistat, the active ingredient in both Alli and Xenical, the FDA indicates that 27 of the cases involved hospitalization and six included liver failure. Symptoms included jaundice, weakness and abdominal pain.

The possibility of Alli and Xenical side effects causing hepatoxicity were also discussed at the CDER Drug Safety Oversight Board in April 2009, and FDA has other cases of suspected liver injury that it is still investigating but has not yet connected definitively to Xenical or Alli use.

The FDA early communication notes that the regulatory agency has not determined that there is a cause and effect relationship between the emerging safety issue and the medications. The agency recommends that consumers continue to use Xenical as prescribed by their physician and Alli as directed.

Consumers have been urged to consult with a healthcare professional if they experience symptoms of liver injury, including weakness or fatigue, fever, jaundice or brown urine. Other symptoms of liver damage could include abdominal pain, nausea, vomiting, light-colored stools, itching or loss of appetite.

The primary known side effects of Alli and Xenical include oily and loose stools, fecal incontinence, frequent or urgent bowel movements and flatulence, which tend to be most severe when the treatment is started and may decrease with time.

There have been suggestions that orlistat could increase the risk of colon cancer and breast cancer, and the consumer advocacy group Public Citizen has called for an Xenical recall since 2006.