What is dexamethasone and how is it useful in treating COVID-19?
Scientists have announced the first major breakthrough in the search for a drug to fight the novel coronavirus since the virus’s onset six months ago in the Chinese city of Wuhan.
A research team at Oxford University has found that in very severe forms of COVID-19, a cheap and widely available drug called dexamethasone can be effective, explains David C. Gaze, a lecturer of Clinical Biology at Westminster University.
Dexamethasone has been around since the beginning of the sixties. It is a steroid frequently given as an anti-inflammatory in low doses and widely used for severe asthma, allergies, and swollen joints. It is also used in autoimmune conditions such as systemic lupus erythematosus or in rheumatoid arthritis, more commonly than others.
It is for this effect on the inflammation and our immune system that makes it useful to battle off the worst COVID-19 symptoms.
How does the drug work?
Most people with COVID-19 have no signs of the disease, are asymptomatic, or have mild symptoms such as dry cough, moderate fever, or loss of taste and odor. But the symptoms are much worse in a small minority, and patients often require oxygen therapy or ventilation. These are the people for whom dexamethasone is the most effective.
Gaze explains that in severe cases, the body’s immune system overreacts to the virus and mounts on the cells that contain it when attacked. This is known as a cytokine storm, in which chemicals called cytokines are released by immune system cells that cause excessive inflammation
Dexamethasone affects the immune system to dampen the response and reduce the storm of cytokines. In effect, it prevents the massive inflammation seen in the patients’ lungs and heart that causes serious respiratory problems.
Where was it tested?
The drug was tested in the largest COVID-19 drug trial known as the Randomised Evaluation of COVID-19 Therapy. Researchers analyzed the drug’s effect in 2,000 patients as part of the study, and compared it to the effects in 4,000 patients who did not receive this.
Results indicate that the greatest benefit was for patients on ventilators, where dexamethasone reduced the risk of death by 30%. There was a 20 percent reduction for those requiring oxygen.
That is equivalent to one life saved on ventilators for every eight and treated with oxygen every 20-25.
What are the side-effects?
The drug’s side effects include anxiety, sleep disorder, weight gain, and fluid retention. These comparatively minor effects can be easily managed for patients in intensive care, thus the benefits of COVID-19 dexamethasone outweigh the negative effects.
In those mild symptoms that do not require respiratory support, the drug is ineffective, and should not be used at home.
This step is important for a search for a solution to end the coronavirus pandemic, however, countries like Pakistan with a weaker healthcare system, it should be ensured that the drug is readily available for patients at a cheaper price.