Xenical, Alli to Carry Revised Warning Label for Risk of Liver Damage
The US Food and Drug Administration has announced today that weight loss drugs containing orlistat will carry a revised label warning of rare, but sometimes severe, cases of liver damage associated with the drug. Orlistat is available by prescription in the medication Xenical and over-the-counter in the drug Alli.
About 40 million people worldwide are taking the drug, according to FDA estimates. Orlistat was first approved in 1999 as a prescription medication. The reduced strength non-prescription version was approved in 2007.
The FDA began its review of orlistat in August 2009 following 32 reports of severe liver injury. Only two of those occurred in the United States. Thirteen of the cases (one in the US) were found to be so severe that they resulted in a score of 4 or 5 using the Drug Induced Liver Injury Network scoring system. A ‘4’ indicates severe liver damage requiring hospitalization and ‘5’ means resulting in death or liver transplantation.
For now, the FDA is only stating that there is an association between the weight loss drug and liver failure. It is not known if orlistat is the actual cause of liver failure or if some people are at higher risk because they metabolize the drug differently than others.
"We are telling consumers and health-care providers to be vigilant should [patients] develop symptoms suggestive of liver impairment," said FDA spokeswoman Elaine Gansz Bobo. "We are not advising routine monitoring of liver enzymes as that will not help predict who may develop hepatic impairment on the drug. We were unable to identify any particular group that may be at increased risk."
The signs of liver failure include jaundice (yellowing of the skin or eyes), dark urine, itching, weakness, and abdominal pain.
Both Roche, that markets Xenical, and GlaxoSmithKline, that sells Alli, are working closely with the FDA.
To report adverse events related to orlistat, contact MedWatch by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at http://www.fda.gov/medwatch, or by mail to MedWatch, FDA, 5600 Fishers Lane, Rockville, Maryland 20852-9787.