Ongoing Safety Review of Weight Loss Drug Orlistat

The U.S. Food and Drug Administration announced today that it is reviewing adverse event reports of liver injury in patients taking the weight loss drug orlistat, marketed as the prescription drug Xenical (orlistat 120 mg) and the over-the-counter medication Alli (orlistat 60 mg).

The drugs were approved for obesity management in conjunction with a reduced caloric diet, and to reduce the risk of regaining weight after prior weight loss.

Between 1999 and 2008, the FDA received 32 reports of serious liver injury, including 6 with liver failure, in patients taking orlistat. Of those cases, 27 reported hospitalization and six resulted in liver failure. Thirty of the adverse events occurred outside the United States. The most commonly reported adverse events included yellowing of the skin or whites of the eyes (jaundice), weakness, and stomach pain.

Reports outlining the adverse events were submitted to FDA’s Adverse Event Reporting System.The FDA is reviewing additional data submitted by orlistat manufacturers on suspected cases of liver injury, and the issue has been discussed at the FDA’s Center for Drug Evaluation and Research Drug Safety Oversight Board.

“The issues here are complex, but FDA has benefited from the input of the Board, including comments from representatives from three FDA Centers and several other Agencies in the Department of Health and Human Services,” said Steven Osborne, M.D., executive director of the Board.The FDA’s analysis of these data is ongoing, and no definite association between liver injury and orlistat has been established at this time.

Consumers taking Xenical should continue to take it as prescribed, and those using over-the-counter Alli should continue to use the product as directed.Consumers who have used orlistat should consult a health care professional if they experience symptoms possibly associated with 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 urges both health care professionals and consumers to report suspected side effects from the use of orlistat to FDA's MedWatch Adverse Event Reporting program

Further information regarding orlistat will be released by the FDA as soon as its review of complete.

Orlistat is manufactured by Swiss pharmaceutical firm Roche. The drug is marketed as Alli by British drugmaker GlaxoSmithKline PLC and sold as Xenical by Roche. The FDA first approved Xenical in 1999 and alli in 2007. Glaxo reported $123 million in sales for Alli in 2008, while Roche posted $472 million in revenue for Xenical.