'Black box' warning for Glaxo's Avandia

8/15/2007- US regulators have approved new “black box” warning labels for GlaxoSmithKline's controversial diabetes drug Avandia.

The warnings, the strictest that prescription drugs can carry in the US, emphasize the drug may trigger congestive heart failure and that patients should be monitored closely by physicians.

The drug’s labeling already contained similar warnings but the new ones will be significantly more prominent.

The warning is also applicable to other drugs in the same class that help patients with type 2 diabetes control their levels of blood sugar. They include Actos manufactured by Japan’s Takeda.

The move may help end some of the uncertainty surrounding Avandia following an investigation by America’s Food and Drug Administration into the possible increased risk of heart problems associated with the drug.

News of the investigation led to a fall in sales of Avandia of up to 40 per cent in the US.

However, the new warnings regarding congestive heart failure are separate from other fears that Avandia may also lead to ischaemic heart attacks.

A review of Avandia and a possible increased risk of heart attacks is ongoing, the FDA said.

Shares in GSK fell from £12.62 to £12.44 in early trading.

GSK has been scrambling to head off a crisis of confidence in the drug since the New England Journal of Medicine published a report in May claiming that the drug increased the risk of heart attacks by 43 per cent. The report has been criticized by other scientists.

GSK is considering cutting or redeploying its sales force as sales of Avandia plummet.

Last year Avandia contributed £1.4 billion to GSK's total turnover of £23.3 billion in 2006.

The company employs 30,000 salespeople, including 9,000 in the US.