A trial known as PRINCIPLE has begun investigating the inhaled corticosteroid budesonide as a treatment for COVID-19 in the UK.
The Platform Randomised trial of Interventions against COVID-19 in older peoPLE (PRINCIPLE) has recruited more than 2,100 individuals in the UK to test several therapies, with the goal of finding treatments for patients over the age of 50 years that could help speed recovery and possibly prevent hospital admissions in an already overburdened system.
Budesonide was picked because it was known to be generally very well tolerated from its widespread use in the treatment of asthma and COPD, with no serious side-effects associated with short-term use.
In other studies this year, the systemic corticosteroid dexamethasone was effective in some patients hospitalised with COVID-19. Researchers postulated that an inhaled corticosteroid could be easily and cheaply administered at home, and if effective might prevent hospital admissions.
The SARS-CoV-2 virus binds to ACE2 receptors that line cells in the airways, and laboratory studies have shown that inhaled corticosteroids can reduce the number of those receptors. This may block entry of the virus into cells.
The inhaled corticosteroid’s anti-inflammatory effects may also slow or minimise damage to the lungs by delivering the agent where it is needed most.