Treatment options for COVID-19

It has been more than 6 months since the first case of COVID-19 was reported in Wuhan, China. From then until now, there have been continuous developments in our understanding of COVID-19 and the associated virus, SARS-CoV-2. But to what extent have the research and studies until now helped control the outbreak or helped reduce the mortality rates?

The mortality rate at the start of the pandemic was estimated to be around 2.3%. According to World Health Organization (WHO) director general's opening statement at a press briefing, as of 3rd March 2020, the global mortality rate was 3.4% 1. As of 26th June 2020, the statistics by Johns Hopkins University (JHU) report that out of about 9.5 million confirmed COVID-19 cases worldwide, more than 480,000 patients have died. According to this, the global mortality rate for the disease, currently, should be around 5%. Thus, it is evident that there has been a continuous rise in mortality ratio. We know that COVID-19 presents different outcomes in different patients. Some patients experience only mild symptoms and recover from the disease with some bed-rest and Paracetamol 2. But many patients experience severe illness and they need to be hospitalized. This is where it becomes important to have effective treatments specific for COVID-19 in order to save patients from dying and to reduce the mortality rates.

Do we have a drug to treat COVID-19 yet?

Although several drugs are being tested to treat COVID-19, we do not have a drug which has proven to be a definitive treatment for the disease yet. Currently, the hunt for an effective treatment continues with more than 150 drugs being researched and tested around the world. Many of these drugs are in clinical trials. Two major ongoing clinical trials are solidarity trial and RECOVERY trial. Solidarity trial, initiated by WHO and its partners, is an international trial currently recruiting 3500 patients from 35 countries 3. The RECOVERY (Randomized Evaluation of COVID-19 Therapy) trial, taking place in the UK claims to have recruited about 5000 patients from hospitals across UK. A lot of the drugs being tested to treat COVID-19 have previously been used to treat Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and other diseases like Ebola. However, some experts have expressed the need to test new compounds specific to SARS-CoV-2 to develop treatments for the disease rather than testing old drugs and treatments in COVID-19 patients (also known as "drug repurposing") 4. But researching and studying new compounds is a time-consuming process. Thus, until such a compound is identified, testing the old drugs in COVID-19 patients seems like a sensible thing to do.

Common drugs and treatment options being tested in clinical trials:

1. Dexamethasone

Dexamethasone is a steroid that was one of the many drugs being tested in the RECOVERY trial by UK. It has recently proven to be effective to treat severe cases of COVID-19. The trial reported that it prevented 1 out 3 deaths for patients on ventilators and 1 out of 5 deaths for patients on oxygen.

Inflammation due to hyperactive immune system becomes a major problem in COVID-19 during the later stages of the disease. Dexamethasone works in a similar manner as the anti-inflammatory hormones produced by the body. The drug suppresses the immune system and helps reduce inflammation in severely ill patients. However, if the drug is administered at an earlier stage or in mild to moderate cases of COVID-19, the suppression of immune system can do more harm than good. This is the reason why dexamethasone has been found to be ineffective in mild and moderate cases of COVID-19. It shows its best effect in critically ill patients.

A major advantage of the drug is that it is relatively cheap. In UK, it only costs £5.40 a day per patient. It is administered intravenously to patients in ICU and in the form of tablets otherwise. The drug is commonly used to treat conditions like severe asthma and rheumatoid arthritis. It is a non-patented drug and thus can be manufactured by many pharmaceutical countries around the world, meaning, there should not be many issues with its availability 5.

Dexamethasone is the only drug until now that has proven to lower the death rates in COVID-19 patients during clinical trials. Therefore, the discovery of its effectiveness is an important milestone in the fight against COVID-19.

2. Antivirals

As the name suggests, antivirals are medicines that are used against viral infections. Most antivirals work by preventing the virus from replicating in the patient's body. Different antivirals use different mechanisms to do this. Below are some of the antivirals being tested to treat COVID-19.

– Remdesivir

Remdesivir was developed by a U.S. based biopharmaceutical company called Gilead Sciences. It works by inhibiting an enzyme called RNA dependent RNA polymerase which is crucial for the virus to replicate its genetic material and produce more copies of itself in the patient 6. Remdesivir is thought to be a promising drug for COVID-19 treatment because it has shown to be effective against other coronaviruses like SARS and MERS in animal studies.