The UK's biggest drug company GlaxoSmithKline  (GSK) got a reprieve after the US Food and Drug Administration (FDA) advisory panel stopped short of removing its blockbuster diabetic drug Avandia from the US market, imposing additional heart risk warnings.

After hearing two days of contradictory facts whether Avandia poses a risk or not to the heart, 20 of the 33 members of the FDA advisory committee voted to keep Avandia on the market, while 12 voted against it and 1 abstained.

But, seven panel  members called for stronger warnings on the drug's label, while 10 asked for sterner language and tighter restrictions on its use. Three members said no changes were required at all.

GSK narrowly escaped in sharp contrast to a 2007 recommendations of a FDA advisory panel, where only 1 of the 23 panel members voted to pull Avandia from the market.

Yesterday's result showed that there is a rising concern that Avandia does have serious side effects but the last say on whether to pull the drug from the market or not is with the FDA, which now will have to act on the panel's decision.

The FDA can take a decision on its own and is not obliged to go by the advisory panel recommendations, though often than not, its rulings are in line with the panel's recommendation.

Withdrawal of the drug could have cost GSK up to $6 billion in potential legal claims, according to a March 2010 UBS analyst report and a loss of £425 million worth of annual sales in the US.

The 33 members of the advisory panel debated over two days on the safety of the drug and whether the side effects of the drug warranted a pull out from the market. They also debated whether the side effects of Avandia were the same or less or more than that of a competing pill, Actos, made by Japanese drug company Takeda.

The decision finally came down to fight diabetes with as many drugs as possible, as the ailment that renders the human body incapable of controlling blood glucose levels affects about 24 million in America alone.

Most of the panel members voted that Avandia's side effects were not more harmful than other similar older drugs in the market.

Separately, Glaxo said it had discontinued testing of Avandia at Indian sites because the Indian regulator wanted a hold on the testing because of safety risks of the drug.

Shortly after launching Avandia in the market in 1999, SmithKline Beecham's research labs began a study to find out whether the drug was safer for the heart than a competing pill, Actos.

The findings showed that Avandia posed significant heart risks, but within a year of its internal research finding, US drug giant SmithKline Beecham merged with British drug giants Glaxo Wellcome in 2000 to form GlaxoSmithKline. (See: Glaxo Wellcome, SmithKline Beecham agree to merge)

Although GSK is required in most cases by the US and other countries' laws to post the research results on its website or submit them to drug regulators, the merged entity chose to ignore the law.

GSK then spent the next 10 years trying to cover up the findings as putting a ''safety risk'' tag to the drug would have resulted in $600 million in lost sales from 2002 to 2004 alone. (See: GlaxoSmithKline: truth is a bitter pill) 

In May 2007, Steven Nissen, chair of cardiovascular medicine and medical director at Cleveland Clinic, published his findings on Avavdia in The New England Journal of Medicine that suggested that the drug increased the risk of heart attacks in diabetic patients.

Both Avandia and Actos are used in the treatment for Type 2 diabetes and Avandia was once GSK's top-selling drug until the side effects of the drug came into public domain that led to shrinking global sales of the pill from £1.4 billion in 2006 to £771 million last year.

GSK has already been bombarded with more than 13,000 lawsuits over Avavdia from users who allege that they had been misled about the drug's safety. This week, the company paid $460 million to settle 10,000 of these claims.

GSK said yesterday that it expects a legal charge of £1.57 billion ($2.4 billion) for the second quarter related to settling claims related to Avandia as well as an investigation into its former factory at Cidra in Puerto Rico and anti-trust litigation over its anti-depressant Paxil.

But GSK's problems on Avandia are far from over as the European regulator has still to rule over pulling the drug out of the European market.