Researchers from Brighton and Hove Medical School and the University of Dundee found that asthmatic children carrying a certain genetic trait - affecting as many as one in seven patients with the disease - are less likely to respond to treatment with GlaxoSmithKline's salmeterol, found in Serevent and Seretide inhalers.

They carried out the first genotyped study comparing additional treatments given to children with asthma who continue to experience symptoms despite using an inhaled steroid preventer.

Children with the susceptible arginine-16 genotype and poorly controlled asthma were randomly assigned to receive either montelukast (Merck & Co's Singulair) or salmeterol for one year in addition to their normal preventer treatment.

The findings, published in the journal Clinical Science, showed that these children responded better to montelukast, experiencing an improved quality of life and less wheezing and coughing compared to those given Salmeterol.

Furthermore, at baseline, 36% of the children were using their relievers every day, but after 12 months the number doing so had halved in the group taking montelukast while no improvement was seen in the salmeterol group.

Salmeterol currently preferred choice

The researchers point out that salmeterol is currently the preferred drug for children with asthma who are not controlled with inhaled steroids, and warned that many responding poorly to the drug may be suffering needlessly from their disease.

Treatment may be made more effective through use of a simple and relatively inexpensive gene test to identify those who might fail to respond to Salmetrol they said, and noted that their results are “a step towards personalised and tailored medicine for asthma”.

In an emailed statement to PharmaTimes UK News, a spokeswoman for GlaxoSmithKline said "the results of this small study raise interesting questions around how different patients can gain the most benefit from their medicines and it warrants further research".