Remdesivir (RDV): Experimental Antiviral for Coronavirus (COVID-19)

What is remdesivir (RDV)?

Remdesivir (RDV) is a synthetic molecule in the antiviral class of medications targeting RNA synthesis. The molecule looks a lot like a DNA nucleoside.

SARS-CoV-2 virus that causes COVID-19 is an RNA virus. (RNA is the molecular transcription tool organisms use to build proteins using DNA instructions). RNA viruses are dependent on an RNA polymerase enzyme to grow the RNA chain.

Through some metabolic processes, remdesivir substitutes itself for essential elements needed by the polymerase, meaning the RNA can’t develop.

Think of the polymerase as a pasta-making machine. You have to take dough and stick it into the pasta machine to make the noodles. RDV is a fake dough — you stick it in, the pasta maker gets jammed up and stops making noodles.

But that’s if the medicine works according to the hypothesis; evidence for its effectiveness against COVID-19, isn’t robust.  A recent COVID-19 study has shown it may shorten hospital stays for severe coronavirus patients, however.

Does remdesivir (RDV) appear to be effective against COVID-19, based on the limited evidence available?

There was only a single randomized control trial for this medication from during the last Ebola outbreak. The RDV arm, along with an antibody arm in the study was stopped after an interim analysis in the ongoing study.

Remdesivir, along with one other drug trial were stopped because of an increase in death among patients taking it, meaning it did not help those patients.

The majority of clinical decisions related to COVID-19 are based on the historical knowledge gained Ebola, SARS, and MERS. The outcomes of RDV’s use in those three disease outbreaks is fairly disappointing.

Is remdesivir FDA approved for treating COVID-19 coronavirus?

Because of the significant public health emergency COVID-19 poses, the antiviral drug remdesivir recently received emergency use authorization (EUA) by the FDA, as reported by Medscape Medical Reference. This means that remdesivir can now be distributed in the U.S. and healthcare providers can treat hospitalized patients with severe COVID-19 with the drug intravenously. 

Qualifying severe COVID-19 symptoms for remdesivir use include low oxygen levels, or requiring oxygen therapy or a ventilator.

As of early May 2020, no other adequate, approved, or alternative treatments for COVID-19 exist other than remdesivir. 

Based on the current data, remdesivir is approved for treating COVID-19 because it may shorten recovery time, but its use will still be deemed experimental.

A clinical trial by Gilead Sciences, the manufacturer of the drug remdesivir, found that a five-day treatment course of remdesivir was just as effective as a 10-day course in severely ill patients, which can potentially free up more treatments for patients. The drug treatments will be donated by Gilead.

Optimal treatment time of remdesivir for COVID-19 is still being studied in clinical trials. Under the EUA as of May 5, 2020, remdesivir will be used to treat the virus in two different treatment durations, based on severity of symptoms: 

• 5-day treatments
• 10-day treatments

Distribution and emergency use of remdesivir is only approved for COVID-19. Remdesivir is still considered an investigational drug and is not approved by the FDA.

What are the side effects of remdesivir (RDV)?

In pre-COVID 19 and other trials, researchers detected:

• Increased liver enzyme levels that may or may not indicate liver damage.
• Researchers documented similar increases in liver enzymes in three U.S. COVID-19 patients.

Typical antiviral drug side effects include:

What is the dosage for remdesivir (RDV)?

The dosing regimen under study in the U.S. for RDV as COVID-19 treatment is as follows:

• An initial one-time dose of 200mg
• Followed by 100mg per day to complete a 10-day or 5-day course

Remdesivir is administered intravenously.

What drugs interact with remdesivir (RDV)?

We don’t think RDV itself affects other medications. The concern is other medications may affect RDV.

There are some medications out there that will boost the RDV level in your bloodstream, and some that will reduce it. Some antibiotics, anticonvulsants, and even herbal products may do this:

Is remdesivir (RDV) safe to take if you are pregnant or breastfeeding?

It is unknown what RDV’s impact on pregnancy is, nor do we know if it is excreted in breastmilk. In rats and monkeys, RDV affected kidney development in fetuses.

Pregnant or nursing mothers should only use remdesivir in consultation with their doctors if the potential benefits outweigh the risks.

How do you get remdesivir (RDV)?

Donation and distribution of remdesivir to hospitals will go toward cities heavily impacted by COVID-19. This will be determined and coordinated by U.S. government officials.

Remdesivir treatment will depend on such factors as the following: 

• Severity of patient illness with qualifying symptoms
• Limited availability of drug supply
• Hospitals with intensive care units or hospitals most in need

Gilead will be working with the U.S. government on how to distribute the drug and announce when the company will begin shipping it under the EUA.

EDITOR’S NOTE: Remdesivir is not FDA-approved. As a result, there is limited published information on this potential COVID-19 coronavirus treatment. The above article uses information and expertise from Dominic Chan, a Portland, Ore. Pharm. D who specializes in medications for infectious disease in the Legacy Health hospital system. Updates include reports from Medscape Medical Reference.