The FDA has declined drugmaker GlaxoKlineSmith’s request to allow its Advair Diskus drug to be prescribed to patients with COPD.

Glaxo said the FDA letter raised concerns about the company’s proposed dosing levels. According to a company statement, Glaxo plans to meet with the FDA to discuss data on side effects connected with Advair.

"We are very surprised and disappointed by this FDA decision particularly given the outcome of the FDA advisory committee meeting earlier this year," said Katharine Knobil, a vice president for development at Glaxo.

In May a panel of 11 medical experts voted unanimously that Advair reduces the risk of the pulmonary disease. The FDA is not required to follow the advice of such panels, although it usually does.

Advair is Glaxo’s best-selling respiratory drug with sales of $3.3 billion in 2006. Advair’s main competitor is Merck & Co.’s Singulair.

On Wall Street, shares of GlaxoSmithKline rose 32 cents to $52.80 in midday trading.