Redemsivir: COVID-19 treatment?
- May 14, 2022
- 4 min read
Updated: May 15, 2022
On 11 February 2020, WHO renamed an unnamed mysterious coronavirus COVID-19, or SARS-CoV-2. It causes symptoms of pneumonia among others and is a cause of concern due to its high infectibility and propensity to cause fatal symptoms in the elderly and people with preexisting health conditions. (First posted 9 June 2020)
Remdesivir has been noted as one of the most effective medications used to treat COVID-19. It is a broad-spectrum antiviral medication developed by Gilead Sciences and has recently been approved by FDA for its use to fight COVID-19. It is administered via injection into a vein and has been authorized for emergency use in the US, and India. It is also approved for use in Japan for people with severe symptoms.
What is COVID-19?
COVID-19, otherwise known as SARS-CoV-2 is a type of coronavirus that bears a resemblance to SARS-CoV, otherwise known as SARS which plagued Asia in 2003. It was first identified in Wuhan China and has spread to the rest of the world since. As of 7 June 2020, the US has had the highest infection rate and the death toll in the world. Below is a rough timeline of the development of COVID-19:
December 31, 2019: Chinese Health officials inform WHO about a cluster of 41 patients with mysterious pneumonia. Most are connected to the Huanan Seafood Wholesale market.
January 1, 2020: Huanan Seafood Wholesale market closes
January 7, 2020: Chinese authorities identify the virus as a novel coronavirus
January 11, 2020: China records the first death linked to the coronavirus
January 13, 2020: First coronavirus infection reported in Thailand
January 20, 2020: First coronavirus infection reported in the US
January 23, 2020: Wuhan is placed under quarantine. The rest of Hubei province soon followed suit.
January 30, 2020: WHO declares the outbreak as a global public health emergency.
Over the next few months, the coronavirus spread across the world, with many countries going into lockdown in an attempt to control the virus. As of May 2020, many countries have begun to ease lockdown restrictions.
Researchers think the coronavirus originated in bats, then jumped to an intermediary species that passed it to people. It is then spread between humans via respiratory droplets within 6 feet. Its infectibility is then increased by its ability to survive for days on some surfaces.
Remdesivir before COVID-19:
Remdesivir was originally developed to treat hepatitis C, a virus that infects the liver. In 2015, remdesivir proved to be useful in treating ebola in rhesus monkeys. In 2018 during the Kivu Ebola epidemic, remdesivir was used in the emergency setting. In 2019 however, monoclonal antibody treatments were proved more effective and the importance of remdesivir use in Ebola became more obscure.
Role of remdesivir in COVID-19 treatment:
Remdesivir acts by binding to the RNA-dependent-RNA polymerase (Rdrp) of the COVID-19 virus. Rdrp is responsible for the replication of the virus within the body. The COVID-19 virus contains RNA as genetic material, which requires the action of rdrp for the genetic material to be replicated and spread to other cells within the body.
In April 2020, it became one of the most prominent treatments for COVID-19. Preliminary data from the U.S national institutes of health suggested that remdesivir was effective in reducing recovery time from 15-11 days in people hospitalized from COVID-19. It was subsequently proven to be more effective than a placebo. However, it is important to note that remdesivir alone is insufficient to treat COVID-19 alone.
Pharmacology and mechanism of action of remdesivir:
Remdesivir diffuses into the host cell before getting converted into its active form. Its active form is of a similar structure to adenosine, an essential component of DNA replication.
Your DNA sequence is determined by your genetic code, which contains 4 main components, A (adenosine), T (thymine), C (cytosine), G (guanine). The genetic code is a sequence of these components, which stores information related to your traits.
The active form of remdesivir, due to its similarity to the structure of adenosine, can get mistaken by the rdrp and incorporated into the genetic code of the virus. However, due to the difference in structure from adenosine, the rdrp is unable to continue adding components of the RNA onto the growing RNA chain, terminating RNA replication.
Drug interactions:
Blood plasma concentration of Remdesivir likely decreases when administered together with St. John's wort, rifampicin, or other cytochrome P450 inducers as it is likely metabolized by cytochrome P450 enzymes.
Adverse events/side effects:
The most common effects of Remdesivir include respiratory failure and organ impairment. It can also cause abnormalities in lab values, such as low potassium, low albumin, low red blood cell, and low platelet counts.
Infusion-related reactions may also occur, such as low blood pressure, nausea, and vomiting.
Increased levels of liver enzymes may also occur, resulting in abnormal liver function tests, indicating potential damage to the liver.
What should you do if you suspect that you are infected with COVID-19?
If you present with symptoms of dry cough and fever, do isolate yourself and visit a doctor or pharmacist. They will be able to assess your symptoms and recommend you do a swab test.
Swab test results are usually made available within 24 hours. During that period, do not interact with anyone else and isolate yourself until you are sure that you do not have COVID-19. If you are infected, continue isolating yourself and await instructions. Based on where you live, the protocols will be different.
References:
Sheahan, T. P., Sims, A. C., Graham, R. L., Menachery, V. D., Gralinski, L. E., Case, J. B., ... & Bannister, R. (2017). Broad-spectrum antiviral GS-5734 inhibits both epidemic and zoonotic coronaviruses. Science translational medicine, 9(396). (Accessible here)
Comments