WASHINGTON - Three influential groups of doctors who treat diabetes urged patients not to stop taking Avandia, saying on Thursday that while news about the controversial drug may be frightening, it would be worse to suddenly stop taking it.

A panel of advisers to the U.S. Food and Drug Administration recommended, but with substantial divisions, that GlaxoSmithKline's diabetes drug stay on the market, despite worries that it may raise the risk of heart attacks.

The experts agreed the drug, known generically as rosiglitazone, raised concerns about heart risks but also agreed it did not seem to raise the risk of death.

The Endocrine Society, American Diabetes Association and the American Association of Clinical Endocrinologists worried that patients may be afraid to take Avandia.

"Patients should continue taking all currently prescribed medications unless instructed otherwise by their health care provider," Dr. Robert Vigersky of the Endocrine Society said in a statement.

"Stopping diabetes medications can cause significant harm and result in higher levels of blood glucose that may cause severe short term health problems and could increase the risk of diabetes-related complications in the long term."

Avandia's global sales have plunged from $3 billion a year in 2006 to $1.18 billion in 2009. But consumer groups estimate it is still taken by at least 2 million Americans.

Glaxo shares rose nearly 2 percent to $37.06 in afternoon trading on the New York Stock Exchange.

The groups did not offer any concrete guidance to patients, saying they rely on the FDA to regulate and on physicians to decide which drugs are best for their individual patients.

"The worst outcome would be to not treat diabetes properly, thereby risking its complications," said Dr. Daniel Einhorn, president of the American Association of Clinical Endocrinologists. "This unintended consequence has happened with past inquiries into diabetes medications, and we very much want to avoid it happening again."

DISAGREEMENTS ON SAFETY

Members of the FDA advisory panel disagreed on whether studies on Avandia provided strong enough evidence to merit taking it off the market. A similar drug, Takeda Pharmaceutical Co's Actos, has not been shown to have the heart attack concern and there are dozens of other drugs diabetes patients can take.

And some experts, including some scientists on FDA staff, strongly feel Avandia is dangerous, as do several consumer groups. But the Diabetes Association and the two groups of endocrinologists said the evidence is not that clear-cut.

"While some analyses have suggested an increased cardiovascular risk with use of the diabetes drug others have not shown substantial evidence of such an association," they said in their statement.

"Patients should be aware that regardless of the opinion and decisions on rosiglitazone, there are numerous drugs available to maintain glucose control in people with type 2 diabetes," the American Diabetes Association's Dr. Richard Bergenstal said.

Hundreds of lawsuits have been filed against Glaxo over Avandia. The company said on Thursday it expected to record a legal charge of $2.4 billion for the second quarter after settling the "substantial majority" of them.