Safety Officials at the U.S. Food and Drug Administration reported that GlaxoSmithKline Plc’s asthma drugs Serevent and Advair, the company’s biggest-selling medications, might have rare and deadly side effects for children. The third asthma drug is called Foradil and is manufactured by Novartis.

Asthma is a chronic respiratory disease which causes inflammation and narrowing of airways in the lung. Serevent and Advair are both used to prevent exacerbation of asthma by relaxing the airways. According to the National Institutes of Health, almost one in ten Americans is diagnosed with Asthma at some time. Almost 21 million adults and 9 million children in the U.S. are currently suffering from this condition.

The medications were approved for children in 2006 in the U.S. Nine patients under age 16 were harmed, including five who died, while being administered Serevent in the last 13 months, according to a safety review posted on the FDA’s Website on Friday.

A meeting of well-known pediatricians to discuss side effects from Serevent and the other medications is scheduled on November 27.

Glaxo’s asthma drugs were being reported as dangerous by the FDA on other occasions too. Two years ago the agency advised consumers to limit the use of the drugs to patients who do not benefit from other similar medication following a study which showed chances of asthma-related deaths among Serevent users increase 400 percent.

The FDA included Serevent among the top five most dangerous prescription drugs on the U.S. market on 2004.

"There is no available pediatric data to indicate that the increased risk of asthma death and life-threatening exacerbations observed in adults does not also apply to children," the latest FDA report noted.

Serevent has more risks than benefits, according to the FDA’s report.

Allergic reactions manifested by difficulty in breathing, throat, lips, tongue or face swelling, dry mouth and nausea, headaches and dizziness number between the possible side effects of Serevent and Advair.

Glaxo’s bestsellers gained $6.13 billion worldwide in 2006 and increased the company’ sales by 12 percent. This revenue made the medicines the second-best-selling in the world behind cholesterol drug Lipitor belonging to Pfizer Inc.