BRUSSELS - Europe's medicines regulator said on Thursday (March 27) there was not enough evidence to support the use of inhaled corticosteroids in patients with Covid-19, but backed the use of dexamethasone based on sufficient data.

Although its Covid-19 task force has not found any safety risks for corticosteroids so far, the possibility of harm to patients who have normal oxygen levels cannot be ruled out, the European Medicines Agency (EMA) said.

Scientists have been studying the benefits of several inflammation-fighting medicines to treat Covid-19, including some arthritis treatments and corticosteroids such as dexamethasone and budesonide.

An infection of the coronavirus can cause swelling in organs, including the lungs, which can also lead to severe complications.

The EMA in September endorsed dexamethasone for treating Covid-19 patients with breathing problems after a British trial showed it helped cut death rates in severely ill, hospitalised patients. The decades-old drug is cheap and widely available.

"More evidence from clinical trials is necessary to establish the benefits of inhaled corticosteroids in people with Covid-19," the EMA said.

Corticosteroids are lab-made medicines which work in the body like the hormone cortisol in fighting and controlling swelling. Inhaled versions are typically used to treat lung problems such as asthma and chronic obstructive pulmonary disease.

A UK trial last month showed treating Covid-19 patients at home with inhaled budesonide can speed up their recovery.

Budesonide is sold as Pulmicort by AstraZeneca.