U.S. warns of liver risk with Glaxo, Roche diet drugs

WASHINGTON (Reuters) - Weight-loss drugs from GlaxoSmithKline PLC and Roche Holding AG will carry new warnings about rare reports of liver injury, U.S. health officials said on Wednesday.

The Food and Drug Administration said it had not determined that Roche's prescription drug Xenical or Glaxo's over-the-counter pill Alli caused liver damage, but felt the public should be alerted because the condition is serious.

Patients should stop taking either medicine and consult a doctor if they notice any signs of liver injury, the FDA said. Symptoms may include itching, yellow eyes or skin, dark urine, light-colored stools or loss of appetite.

The FDA said it reviewed 12 cases of severe liver damage in patients outside the United States who took Xenical, and one in a U.S. patient who took Alli. Two died and three needed liver transplants.

Some patients took other drugs or had conditions that may have contributed to liver damage, the FDA said.

An estimated 40 million people worldwide have taken Xenical or Alli, the FDA said. Both medicines contain the ingredient orlistat. Xenical was approved in 1999 and Alli, which contains half the amount of orlistat as Xenical, was cleared in 2007.

Roche said in a statement the company and the FDA agreed to add the information about liver damage to the precautions listed on Xenical's prescribing instructions.

"We will continue to monitor the safety profile of Xenical and provide this information to the FDA," the company said.

Alli's label will warn patients about rare reports of liver injury and its symptoms, Glaxo said.

The company "wants people to have the information they need to choose the right weight loss aid for their situation," Dr. Howard Marsh, chief medical officer for GSK Consumer Healthcare, said in a statement.

Alli's global sales totaled about $317 million in 2009. Worldwide sales of Xenical in 2009 hit about 400 million Swiss francs ($345 million).

Glaxo shares slid 0.6 percent to $32.74 in afternoon trading on the New York Stock Exchange. Roche shares closed 1.3 percent higher in Swiss trading.

(Reporting by Lisa Richwine; editing by Gunna Dickson and Maureen Bavdek)