The Food & Drug Administration (FDA) is conducting a safety review of orlistat, the popular weight-loss drug sold over-the-counter as Alli, and in prescription form under the name Xenical. According to the agency, Xenical and Alli have been associated with more than 2 dozen reports of liver injuries.
Xenical, which is made by Roche, was approved in 1999. Alli, a lower-dose version of the drug that is made by GlaxoSmithKline, was approved for over-the-counter sales last year. Alli became enormously popular as soon as it hit stores, generating sales of $131 million in its first full year on the market.
Unlike other weight loss remedies, neither Alli nor Xenical work by suppressing the appetite or increasing metabolism. Instead, orlistat prevents the digestive system from absorbing dietary fat, thereby reducing daily calorie intake. Both Alli and Xenical are meant to be used in conjunction with a low-fat diet.
According to an FDA Early Communication issued today, between 1999 and October 2008, 32 reports of serious liver injury, including 6 cases of liver failure, in patients using a version of orlistat were submitted to the FDA’s Adverse Event Reporting System. The agency said 30 of the 32 reports occurred outside the United States. The most commonly reported adverse events described in the 32 reports of serious liver injury were jaundice (yellowing of the skin or whites of the eyes), weakness, and abdominal pain. Hospitalization was reported in 27 of the 32 cases.
Despite the safety review, the FDA is not advising healthcare professionals to change their prescribing practices with orlistat. The agency said consumers currently taking Xenical should continue to take it as prescribed and those using over-the-counter Alli should continue to use the product as directed. However, users of either drug should consult their health care professional if they are experiencing symptoms possibly associated with the use of orlistat and development of liver injury, particularly weakness or fatigue, fever, jaundice or brown urine. Other symptoms may include abdominal pain, nausea, vomiting, light-colored stools, itching, or loss of appetite.
The FDA said it will communicate its findings to the public as soon as its review of orlistat is complete.