What is dexamethasone and how can it be used to treat Covid-19?

    17 June 2020

    In my medical career I have used the steroid drug dexamethasone countless times from the very start of life to its end, and at all points in between. Its powerful anti-inflammatory effects can help the breathing of premature babies in the early days of their life, and relieve the symptoms of people with terminal cancer in their last ones. It is a most helpful treatment in children with severe croup, people with eye inflammation, and in a wide range of conditions where severe inflammation needs to be reduced including asthma, rheumatoid arthritis and inflammatory bowel disease. Used since the 1960s, we know the drug inside out, including its side effects and long-term risks, and it also has another important aspect to it. It is cheap.

    The news that it has now been shown to significantly reduce the risk of dying from COVID-19 for seriously ill patients requiring respiratory intervention is obviously a huge step forward in the long-term management options of the pandemic and will undoubtedly save many lives in the months and years to come.

    The clinical work that has discovered this – known as the RECOVERY trial – found that the use of dexamethasone cut the risk of death by a third for patients on ventilators, and by a fifth for those on oxygen. One of the reasons for its success almost certainly lies in its ability to reduce or turn off a reaction that can be triggered by the body when trying to fight the coronavirus off, known as a cytokine storm. In this over-reaction, the immune system reacts abnormally strongly against the virus and can prove rapidly fatal. Although usually given in tablet form, it can be used intravenously in intensive care and costs around £5 per patient which is as cheap as chips compared to some of the antiviral drugs currently being trialled. The study findings suggest that one life now may be saved for every eight patients on a ventilator, and for every 25 treated with oxygen. When these figures are extrapolated globally the potentially huge impact of the drug can clearly be seen especially as half of all patients with the virus who require ventilation do not survive currently.

    There are, as always, caveats here. This exciting development only applies to the sickest of patients with COVID-19 who are in intensive care (and 19 out of 20 patients with coronavirus recover without requiring hospital admission). Dexamethasone appears to have no impact on people with mild symptoms who have no breathing difficulties and there is no benefit in it being used in the community for the coronavirus. It does not prevent anyone contracting the illness, nor does it lessen the need for measures such as social distancing, face masks and strict hygiene practices.

    Before this development, the only other drug that had been shown to have a potential benefit with the virus was the antiviral remdesivir that had previously been used in treating Ebola. However, it is still not clear whether this has any impact on mortality, its supply is limited and it is expensive. The NHS currently has around 200,000 courses of dexamethasone stockpiled and readily available to any patient requiring it. To have such a treatment that has now been shown to save the lives of some of the sickest patients with coronavirus is not the beginning of the end of the medical battle (far from it) but might – just might – be the end of the beginning.