The Food and Drugs Authority (FDA) has issued a warning against the use of dexamethasone for the prevention of the novel coronavirus disease.

Dexamethasone, a steroid drug, has been hailed in the UK as a breakthrough in the fight against coronavirus.

However, in a statement issued on Wednesday, June 17, 2020, the FDA explained that the drug is shown to be beneficial only in preventing some deaths in COVID-19 patients on ventilators and oxygen and not asymptomatic or mild to moderately ill patients.

“Dexamethasone is a corticosteroid and is classified as a Prescription-Only-Medicine and should only be prescribed and used under medical supervision in COVID-19 or for any other disease,” the FDA statement indicated.

The FDA also explained that dexamethasone suppresses the immune system, and in the UK study, this effect was beneficial and needed in order to suppress the clinically problematic excessive immune reaction in severe and critical COVID-19 cases.

It said dexamethasone should therefore not under any circumstances be used for the prevention of COVID-19 as its potential to suppress the immune system will counteract the body's natural function to fight against COVID-19 and other infections in long-term use.

“The public is therefore cautioned against the purchase, stocking and use of dexamethasone or any other corticosteroid medicine unless certified by healthcare professionals,” the FDA warned.