ROCKVILLE - TWO asthma drugs, GlaxoSmithKline PLC's Serevent and Novartis AG's Foradil, pose serious risks that outweigh their benefits for treating adults, adolescents and children, a US advisory panel ruled on Thursday.

Two much more widely used drugs - Glaxo's Advair and AstraZeneca PLC's Symbicort - have acceptable safety for asthma patients of all ages, the panel said in a series of votes.

The US Food and Drug Administration will consider the recommendations as officials decide if the inhaled drugs should continue to be approved for treating asthma amid evidence of deaths and serious asthma attacks in some patients.

Serevent and Foradil contain long-acting beta agonists, or LABAs. Advair and Symbicort add an inhaled steroid to a LABA.

Panel members said use of a LABA alone appeared to increase risks and the drugs should only be used when paired with a steroid.

'It looks like use of LABAs alone is more dangerous,' said consumer advocate Sidney Wolfe, director of Public Citizen's Health Research Group.

The agency could decide to revoke approval of Serevent and Foradil for asthma, but the drugs could still be sold for treating another lung disease, chronic obstructive pulmonary disease (COPD).

Advair is Glaxo's best-selling drug with $5.6 billion (S$8.32 billion) in worldwide sales through the first nine months of the year.

Symbicort's sales for the same period were $1.5 billion.

Glaxo defended Serevent and Advair as safe and providing benefits of better lung function, symptom relief and fewer asthma attacks.

AstraZeneca and Novartis said the benefits of their drugs outweighed the risks when used as directed. Schering-Plough Corp markets Foradil in the United States. -- REUTERS