GlaxoSmithKline has defended its blockbuster Advair after regulators in the USA included the drug as one of four asthma treatments they wish to see used less often by patients.

The US Food and Drug Administration has announced that long-acting beta agonists (LABAs) should never be used alone in the treatment of asthma in children or adults and manufacturers will be required to include this warning in the product labels. The drugs in question are Advair (fluticasone/salmeterol) and GSK’s single agent Serevent (salmeterol), as well as AstraZeneca's combo Symbicort (budesonide/formoterol) and Novartis and Merck & Co’s Foradil (formoterol).

In December 2008, an FDA advisory panel said the risks of the two LABA-only drugs – Serevent and Foradil – outweighed their benefits but backed the use of Advair and Symbicort as they contain an inhaled corticosteroid. Now the agency says it is taking steps “to reduce the overall use of these medications”.

Badrul Chowdhury, director of the Division of Pulmonary and Allergy Products in the FDA’s Center for Drug Evaluation and Research, said that “although these medicines play an important role in helping some patients control asthma symptoms, our review of the available clinical trials determined that their use should be limited, whenever possible, due to an increased risk of asthma exacerbations, hospitalisations and death,” The FDA will also be requiring the aforementioned companies to conduct additional studies to further evaluate the safety of LABAs when used in combination with inhaled corticosteroids.

The drugmakers have 30 days to agree with the proposed label changes or state why they are not warranted and GSK has already spoken out. The company said “there is no evidence from more than ten years of data from clinical trials, observational studies and worldwide clinical experience exceeding 30 million patient-years of use that Advair is associated with an increased risk of asthma-related death, hospitalisation or other serious respiratory-related outcomes in any age group”.

GSK added that there have been no asthma-related deaths in clinical trials involving nearly 18,000 patients taking Advair. Katharine Knobil, vice president for respiratory clinical research at the firm, added that “we will work with FDA to ensure that the final label for these products protects the interest of patients who suffer with this chronic and serious disease”.

She added that “it is important that doctors have flexibility to make the proper clinical decisions to help patients gain and maintain optimal control of their asthma”. Advair is a big earner and fourth-quarter sales for chronic obstructive pulmonary disease as well as asthma, reached £1.37 billion. AstraZeneca’s Symbicort sales for the same period increased 22% to $666 million.