Treating Covid-19 patients at home with a commonly-used inhaled asthma drug called budesonide can speed up their recovery, according to UK trial results on Monday which doctors said could change the way the disease is treated around the world.

Researchers behind the trial - known as Principle - said the findings were only an interim analysis at this stage, but could soon lead doctors to prescribe budesonide inhalers to patients infected with Covid-19 but not sick enough to be hospitalised...