A granulated formulation of an asthma drug has been produced for young children aged six months to five years.
Children can struggle with inhalers
The new version of Singulair (montelukast) can be mixed with foods or taken alone.
It belongs to a family of asthma drugs that are recommended when others fail to control symptoms.
Experts said the granules, made by Merck Sharp & Dohme, would be a welcome option for some infants, who can struggle with tablets or inhalers.
The government has been calling on drug companies to make child-friendly drugs and to test them in children.
Around 40% of medicines prescribed to children have never actually been tested on children. For newborn babies, the figure is 65%.
Treatments are already available for young children with asthma, including a chewable tablet form of montelukast for children aged 6 to 14 years.
The granulated version is designed for children younger than this.
Montelukast belongs to a class of drugs known as the leukotriene receptor antagonists.
These are recommended when a child has not responded to things like bronchodilators and as an alternative to inhaled steroids.
Katie Shepherd from Asthma UK said: "Parents may be concerned that their child is not getting the full benefit of their asthma medication if they find it difficult to get their child to take tablets or inhalers properly.
"New methods of treatment delivery that increase choice and may make asthma medications more effective can only be welcomed."
Dr John Haughney, who was involved with drawing up the British guidelines on asthma management, said: "This could be useful for a small group of patients, but inhaled steroids remain the cornerstone of asthma therapy."
Dr Richard Russell from the British Thoracic Society said: "The BTS welcomes all innovations in drug therapies for different categories of patients - in this case, infants."
GP Dr Dermot Ryan, said: "To have something like this available for some children is going to be a major boost."
He said about 20% of children aged five and younger have some bouts of wheeze. But not all of these are asthma.
"It's certainly useful to have something available to treat children because they cause a lot of distress to their parents even if they are not particularly distressed themselves," he said.