Severe Liver Toxicity Added to Already Lengthy List of Risks for Diet Drug Orlistat (XENICAL, ALLI)

Prescription and over-the-counter (OTC) versions of the diet drug orlistat (XENICAL, ALLI) are now required to contain new safety in­formation about cases of severe liver injury associated with the use of the drug in their labeling, according to a May 26 announcement by the Food and Drug Ad­ministration (FDA).

The FDA approved 120-milligram pills of orlistat as a prescrip­tion drug in 1999 for weight control in conjunction with a reduced-calorie diet. In 2007, a 60-mil­ligram pill of orlistat was approved for OTC use for weight loss in overweight adults in conjunction with a reduced-calorie and low-fat diet. Orlistat in either prescription or OTC form is currently approved for marketing in approximately 100 countries.

In August 2009, the FDA an­nounced it was reviewing safety information regarding reports of liver-related adverse events in patients taking orlistat. During this initial review, 32 reports of serious liver injury, including six cases of liver failure, were identified.

The FDA then conducted a complete review of available data on severe liver injury associated with 120-milligram doses of orlistat through Aug. 7, 2009, and a review of post-marketing reports on 60-mil­ligram doses of orlistat from 2007 through Oct. 1, 2008. This final review identified 13 cases of severe liver injury.

Of the 13 cases of liver injury, 12 were reported with the use of orlistat in 120-milligram doses and one was reported with the use of the 60-mil­ligram product. In some of these cases, other factors or drugs may have contributed to the development of severe liver injury.

Of the 13 cases, two patients died from liver failure, and three patients required liver transplants.

Public Citizen has been concerned about or­listat and opposed to its approval from the very beginning. We testified before the FDA’s Endo­crinologic and Metabolic Drugs Advisory Com­mittee in May 1997 against the approval of the drug. In 2006, we also testified against the switch to OTC and petitioned for the drug to be banned altogether.

Orlistat was approved without scientific evidence showing that there is a health benefit for those who use it. In other words, there is no evi­dence that orlistat, or any diet drug, will reduce risk of premature death or illness associated with long-term obesity and inactivity.

What You Can Do

Do not use orlistat. This drug has a meager effect on weight, but its potential to cause serious side effects, including pre-cancerous lesions of the colon (aberrant crypt foci), liver damage and pancreatitis, is significant. The most common side effects of orlistat include oily spotting, gas with discharge, fecal urgency, fatty/oily stools and fre­quent bowel movements.

Contact your health care provider immediately if you develop any of the following symptoms, as they may signify potentially serious liver problems:

• Yellowing of the skin or whites of the eyes (jaundice)
• Unusually dark urine
• Loss of appetite that lasts several days or longer
• Nausea
• Abdominal (lower stomach) pain

Consumers may report serious adverse events or product quality problems with the use of orlistat to the FDA’s MedWatch Adverse Event Reporting program either online, by regular mail, fax or phone.

Online: https://www.accessdata.fda.gov/scripts/medwatch/med­watch-online.htm 
Regular Mail: Use postage-paid FDA Form 3500. Mail to Med­Watch, 5600 Fishers Lane, Rock­ville, MD 20852-9787
Fax: (800) FDA-0178
Phone: (800) FDA-1088