An inhaled steroid will be investigated as a possible treatment for coronavirus as part of a national trial.

Budesonide will form part of the UK’s priority platform trial for Covid-19 treatments that can be taken at home.

Led by the University of Oxford, the Principle (Platform Randomised trial of INterventions against Covid-19 In older peoPLE) trial is evaluating treatments that can help people aged over 50 recover more quickly from coronavirus and prevent the need for hospital admission.

Inhaled corticosteroid budesonide is commonly prescribed as part of the long-term management of asthma and chronic obstructive pulmonary disease with no serious side-effects associated with short-term use.

In some patients with Covid-19, the body mounts a significant immune response to fight the virus, causing high levels of inflammation that can damage human cells in the airways and lungs.

Research suggests inhaling budesonide into the airways targets anti-inflammatory treatment where it is needed most and can potentially minimise any lung damage that might otherwise be caused by the virus.

Sars-CoV-2, the virus that causes Covid-19,  binds to ACE2 receptors lining cells in the airways, gaining entry to human cells and replicating within.

Laboratory studies suggest inhaled corticosteroids reduce the number of these receptors in the airways and so may block entry of the virus into human cells.

Professor Chris Butler at the University of Oxford, who led the Principle trial, said: “Budesonide is relatively inexpensive, safe and easy-to-administer drug for respiratory conditions that may have a role to play in treating Covid-19.

“It is only through enrolling volunteers on a randomised controlled trial like Principle that we can assess whether there are clear benefits or harms associated with potential treatments like budesonide.

“We need many more volunteers to join the trial so we can get the answers we really need to keep people with Covid-19 out of hospital.

“Like vaccines and preventative measures, treatments have an important role to play in minimising the burden of this disease on society.”

Trial participants will be randomly assigned to receive an inhaler in the post and the usual standard-of-care from their clinician.

They will be asked to inhale two puffs twice a day for 14 days with each puff providing a 400 microgram dose of budesonide.

They will be followed-up for 28 days and will be compared with participants who have been assigned to receive the usual standard-of-care only.