Dexamethasone is used to treat conditions such as arthritis, blood/hormone/immune system disorders, allergic reactions, certain skin, and eye conditions, breathing problems, certain bowel disorders, and certain cancers. It is also used as a test for an adrenal gland disorder [i]
One way that it works is to decrease inflammation in the body. It has been used for Cancer patients. Dexamethasone reduced death rates by around a third among the most severely ill COVID-19 patients that have admitted to hospital. The trail of this drug is only given to those who have COVID-19 and are on ventilators or are on oxygen.
Full details of the trial have not yet been published. Germany’s Fresenius SE (FREG.DE) is the largest supplier of this drug.
Dexamethasone was first made in 1957 and was approved for medical use in 1961. It is on the World Health Organization’s List of Essential Medicines. Source:[ii]
On 16 June 2020, the Oxford University RECOVERY Trial (Randomized Evaluation of COVid-19 Therapy) in the United Kingdom, announced preliminary results that low-dose dexamethasone treatment (6 mg per day either through oral administration or by intravenous injection) can reduce the death rate by approximately one-third in COVID-19 patients on ventilators and by one-fifth in COVID-19 patients on oxygen. No benefits to patients not requiring respiratory support was observed. As of 16 June, the full details of this research have not yet been published. Source:[iii]
Image source: https://en.wikipedia.org/wiki/Dexamethasone