HUNDREDS of thousands of asthmatic children may be getting little benefit from the most commonly used inhaler in the UK, researchers claim.

If used daily, salbutamol may fail to prevent asthma attacks in children who have a genetic mutation, they said.

More than 100,000 youngsters have a double copy of a gene which makes them more than 30% more likely to suffer asthma attacks if they take salbutamol daily compared with those without the gene. Even children with a single copy of the gene have an increased risk of asthma attacks if they use the inhaler – relating to some 350,000 to 400,000 British children.

But the researchers said that, while the study was important, there was no need for youngsters to switch inhalers until more research was carried out.

Salbutamol is more commonly known under the brand name Ventolin.

The study found children with a genetic change called Arg16 did not respond well to salbutamol – or a sister drug, salmeterol – if they took it daily.

All children in the group were taking salbutamol as a reliever inhaler for attacks, but were also on a longer-acting inhaler to control their symptoms.

Professor Somnath Mukhopadhyay, from Brighton and Sussex Medical School, who worked on the study, said: “Our research also found 70% of children with a double copy of the gene had asthma attacks compared with 45% of those without the gene.”