Aug. 24, 2009 -- The FDA today announced that it is reviewing adverse event reports of liver injury in patients taking the weight loss drug orlistat, marketed as the prescription drug Xenical and the over-the-counter medication Alli.
Xenical was approved by the FDA in 1999; Alli was approved in 2007 as an over-the-counter weight loss aid for adults.
Thirty of the 32 reports occurred outside the U.S., the FDA notes. Orlistat is approved in about 100 countries.
The FDA is reviewing additional data submitted by orlistat makers on suspected cases of liver injury. The issue was also discussed in April 2009 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," Steven Osborne, MD, executive director of the FDA's Drug Safety Oversight Board, states in an FDA news release.
The FDA is still analyzing the data and states that "no definite association between liver injury and orlistat has been established at this time." That means that it's not clear that orlistat caused the reported cases of liver injury. The FDA will release its findings on orlistat as soon as its review is completed.
In the meantime, the FDA isn't recommending any prescribing changes for orlistat and no changes in use of Xenical or Alli.
"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," states the FDA.
The FDA also recommends that people who have used orlistat 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.
Drug Companies Respond
Xenical is marketed by Roche. "Patient safety is very important to us and we continue to work very closely with the FDA. At this time, per the FDA's alert, no causal relationship can be established and changes in prescribing are not recommended," a Roche spokesman Terry Hurley told WebMD.
Alli is marketed by GlaxoSmithKline. "There is no evidence that Alli causes liver damage," Deborah Bolding, communications manager-North America for GlaxoSmithKline Consumer Healthcare, tells WebMD in an email. Bolding notes that Alli is "minimally absorbed in the blood and works locally in the gastrointestinal tract. There is, therefore, no obvious biological mechanism to suggest liver damage can occur with Alli."
"Liver changes can have many causes," Bolding says. "People who are overweight and obese are predisposed to liver-related disorders." Bolding says consumer safety is of "utmost importance" to GlaxoSmithKline and that orlistat is "the most-studied weight loss medicine, with safety established through 100 clinical studies involving more than 30,000 patients."