Rare Cases of Severe Liver Injury Linked to Orlistat

The FDA has completed its safety review of the weight-loss medication orlistat, and the agency has approved a revised label for the prescription version of the medication -- which is marketed as Xenical -- and a new label warning for the OTC product version, which is marketed as Alli.

The updates alert consumers that there have been rare reports of severe liver injury associated with both product versions.

The FDA announced in August 2009 that it was reviewing the products. In a May 26 safety announcement, the agency said it had identified 12 foreign reports of severe liver injury with Xenical and one domestic report of severe liver injury with Alli.

FDA officials emphasized that the cases were rare given that 40 million people worldwide have used the medications. However, two of the patients died from liver failure, and three required liver transplants.

The FDA acknowledged that a cause-and-effect relationship between orlistat and severe liver injury has not been established. The agency noted that some patients in the reported cases also used other drugs or had other conditions that may have contributed to the development of severe liver injury.

However, due to the serious nature of the injuries reported, the agency has added information about the reported cases to the product labels to educate consumers about the signs and symptoms of liver injury and the need to see a physician promptly should they occur.

The FDA said physicians should instruct patients to report any symptoms of hepatic dysfunction -- including anorexia, pruritus, jaundice, dark urine, light-colored stools or right-upper-quadrant pain -- when using Xenical or Alli.

If liver injury is suspected, orlistat and other suspect medications should be discontinued immediately, agency officials said. Furthermore, liver function tests and aspartate aminotransferase and alanine aminotransferase levels should be obtained.

Adverse events associated with the use of Xenical or Alli should be reported to the FDA's MedWatch program.

The FDA advised physicians and consumers to weigh the benefits of using Xenical or Alli for weight loss against the potential risks when determining if these medications are appropriate.