All about dexamethasone, which researchers say is a 'breakthrough' Covid-19 treatment

• In a breakthrough trial, dexamethasone appears to be a Covid-19 miracle 
• This common corticosteroid is widely used to treat inflammatory conditions
• The details of the trial still need to be released before we can know exactly which patients are likely to benefit

Researchers led by a team from the University of Oxford administered the widely available drug to more than 2 000 severely ill Covid-19 patients, mostly on ventilators. Deaths of those patients were reduced by 35%.

But what is this widely available, affordable steroid that made the headlines?

For what is dexamethasone usually prescribed?

Dexamethasone is a corticosteroid, which is similar to a natural hormone we all produce in our adrenal glands. When your body doesn’t make enough of this hormone, it needs to be replaced.

Dexamethasone is usually prescribed to relieve inflammation such as swelling, redness and pain in the body. Doctors prescribe this medication for certain forms of arthritis and severe allergic reactions that can lead to swelling, as well as asthma.

Why did scientists experiment with this as a Covid-19 treatment?

Since early in the Covid-19 outbreak, Health24 has been reporting on scientific testing of various existing medications as a treatment for Covid-19. As the SARS-CoV-2 virus is new, there is not yet any specific antiviral vaccine to treat Covid-19.

Scientists, including those collaborating in the World Health Organization Solidarity Trial, looked at various types of medications, including hydroxychloroquine, usually prescribed for lupus, and remdesivir, an antiviral medication. 

 A project called the RECOVERY trial was launched in March 2020 to test the efficacy of dexamethasone. At first, the WHO and other countries cautioned against the use of steroids to treat viral respiratory infections such as Covid-19, according to Peter Hornby, an infectious-disease specialist at the University of Oxford and chief investigator on the trial.

Data of steroid use in SARS and MERS, also caused by coronaviruses, were inconclusive. But as dexamethasone is such a readily available drug and showed promising results from previous studies during outbreaks, Hornby felt that it needed to go through a clinical trial.

A steroid drug suppresses the immune system, which can help those Covid-19 patients whose lungs are severely affected by an overreactive response from their immune systems. The WHO was sceptical, as patients still need a functional immune system to fight SARS-CoV-2 and the Covid-19 infection.

What are possible side effects from normal use?

As with any other medication, dexamethasone may cause some side effects. Side effects that were most commonly reported in the past include:

• Upset stomach and vomiting
• Headache
• Dizziness
• Restlessness
• Anxiety or depression
• Increased hair growth
• Insomnia
• Irregular menstrual cycle
• Bruising

What about corticosteroids and diabetes?

Unfortunately, the use of corticosteroids to treat inflammation can lead to higher than normal blood glucose levels and insulin resistance, and if they are used long-term, may lead to type 2 diabetes.

 As those with diabetes are more at risk for severe Covid-19 complications, the use of dexamethasone might be a concern, but typically, the effect on blood glucose only counts if corticosteroids are administered for a long period of time.

A study published in the British Journal of Anaesthesia found that 10mg of dexamethasone was enough to raise the blood glucose levels of non-diabetic and type 2 diabetic patients undergoing abdominal surgery. The outcome was that hyperglycaemia may occur in those with poorly controlled diabetes and severe obesity – two profiles especially at risk for severe Covid-19.

However, blood glucose levels should return back to normal as soon as one has finished the course of this medication, but people with pre-existing risk factors for type 2 diabetes, may be diagnosed with diabetes after use. This is especially the case when taking dexamethasone or any other corticosteroid orally.

It is said that non-oral methods of administering, such as injections, might have a lesser effect on the glucose level and might be better for those prone to type 2 diabetes or those who already have it.

But the exact effect of dexamethasone in patients with Covid-19 and diabetes as an underlying condition is not yet known. 

If I have mild Covid-19, will the drug help me?

According to Nahid Bhadelia, a physician at the Boston Medical Centre, the initial results from this trial looked remarkable for those who were already severely ill from Covid-19.

“I can see ICU physicians being more likely to provide steroids in the critically ill who are mechanically ventilated and who are not improving from other interventions based on these results,” she stated. But she also added that she was disappointed that the RECOVERY trial team did not release more information on exactly what subset of Covid-19 patients would benefit from dexamethasone.

Therefore, it’s vital to understand that we still need more details about the efficacy of dexamethasone before we know who can receive this treatment safely. It is not meant for mild cases of Covid-19 and one should not be taking a corticosteroid such as dexamethasone without clear instructions from a doctor.

Is dexamethasone the Covid-19 solution?

Martin Landray, an epidemiologist at the University of Oxford and another chief investigator of the trial remains optimistic about the breakthrough of dexamethasone as a Covid-19 treatment. He stated that its affordability and it being a medical staple is a particular benefit in countries with limited access to healthcare.

Information about the trial was made available in a press statement released on 16 June 2020, but the findings of the trial are not yet available. The researchers said that they are aiming to publish the results as soon as possible and share their findings with regulators worldwide. But many are already optimistic.

The National Health Service from the United Kingdom announced that standard clinical guidelines for Covid-19 patients will allow for dexamethasone.

And in South Africa, Dr Zweli Mkhize, Minister of Health, announced in a statement on the SA Coronavirus website that the Ministerial Advisory Committee on Covid-19 has issued an advisory pertaining to the clinical applications of dexamethasone and that they were “extremely excited about this important breakthrough”.

Landray understands that other experts want to see more details first before getting too excited. But in a situation where so many people were dying, he stated that it was important to get the basic message out right away.

"There is this tension between having the final details and the final decimal points nailed down, and having what is actually a clear-cut and practical message in the public domain,” he said.

“The decimal points might change a bit when we tidy things up, but we’ve got to a point where the message will not change,” Landray stated.

READ | The lowdown on Covid-19 treatments

READ | Covid-19: What's next for hydroxychloroquine?

READ | Remdesivir will not be enough to curb Covid-19, study finds

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