Overview and Background

Remdesivir, produced under the trade name Veklury, is what doctors call a broad-spectrum antiviral drug, meaning that it may be effective in fighting a range of different viruses that may infect people.

Initially, remdesivir was developed with hopes that it would be an effective treatment against hepatitis C. Like SARS-CoV2 (the virus that causes COVID-19), the hepatitis C virus belongs to a category of viruses that scientists call RNA viruses. This means that the genetic material carried inside of these viruses consists of a molecule of RNA.

In order to reproduce, an RNA virus must enter cells of a host. Once inside a host cell, the virus produces an enzyme called an RNA-dependent RNA polymerase (RdRp). This enzyme enables the virus to reproduce many more molecules of RNA.

Along with hijacking some of the host cell’s own machinery, this reproduction of viral RNA allows the virus to produce additional virus particles that then go on to infect other cells.

Being what doctors call a “prodrug”, remdesivir transforms into a slightly different chemical once it gets into the body. This new chemical, which is the actual drug, is intended to interfere with the RdRp enzyme.

While early laboratory research demonstrated remdesivir to be a potential treatment for hepatitis C, it didn’t work well when tested in patients. It was later considered and tested as a treatment against infection resulting from the Ebolavirus, which also is an RNA virus, but it didn’t work well as treatment for Ebola either.

Remdesivir is approved to be administered to pregnant women in who would be able to receive remdesivir treatment in a normal situation where they were not pregnant.

Very little is known about remdesivir in nursing mothers. However, because it does not absorb well when taken orally, remdesivir is administered intravenously and is unlikely to be absorbed by the baby through breastmilk.

Appropriate Patients for Remdesivir

Based on initial preclinical laboratory studies on cells and in test animals, clinical (human) studies, and continuous experience with the COVID019 pandemic, doctors think that remdesivir can help shorten the recovery time in certain patients with COVID-19.

Because of this, remdesivir is being provided as a treatment for COVID-19 in certain situations. Most notably, this means adult patients and children who are at least 12 years old and weigh at least 40 kg (88 lbs.), who are hospitalized for moderate to severe COVID-19.

In pediatric patients below the age of 12 and who weigh less than 40 kg (88 lbs.), the use of remdesivir for COVID-19 related recovery is less certain. Remdesivir may be given to small pediatric patients, including neonates weighing at least 3.5 kg (7.7 lbs.), however, as of early 2022, there are very few data supporting this usage. As for giving remdesivir to newborn babies weighing less than 3.5 kg (7.7 lbs.), data are so limited that doctors considering this are instructed to contact Gilead Sciences, Inc, the company that makes remdesivir, to fully discuss the option in connection with a clinical trial.

In pediatric patients below the age of 12 and who weigh less than 40 kg (88 lbs.), the use of remdesivir for COVID-19 related recovery is less certain. Remdesivir may be given to small pediatric patients, including neonates weighing at least 3.5 kg (7.7 lbs.), however, as of early 2022, there are very few data supporting this usage. As for giving remdesivir to newborn babies weighing less than 3.5 kg (7.7 lbs.), data are so limited that doctors considering this are instructed to contact Gilead Sciences, Inc, the company that makes remdesivir, to fully discuss the option in connection with a clinical trial.

Appropriate Settings for Remdesivir

In pregnant and non-pregnant people alike, remdesivir can be given in cases of COVID-19 severe enough that the patient needs to be in the hospital and needs to receive supplemental oxygen.

The supplemental oxygen can be either low-flow oxygen through a tube in the nose (nasal cannula) or a mask, or it can be high flow oxygen given through what doctors call non-invasive ventilation (NIV) devices. Such devices include non-rebreather masks, high-flow nasal cannulae, and continuous positive airway pressure (CPAP) machines.

However, if COVID-19 becomes so severe that is reaches a point were NIV is not enough, meaning that a patient needs either mechanical (invasive) ventilation or what doctors call extracorporeal membrane oxygenation (ECMO), the usefulness of remdesivir decreases.

How Remdesivir is Administered

Remdesivir is administered by intravenous (IV) infusion, once per day, over a period of 30-120 minutes. Usually, this is done for five days, with double the amount of the drug infused on day 1 (loading dose) compared with the other four days.

In some cases, the remdesivir treatment can be extended up to a total of ten days. Remdesivir is administered only to patients who are in the hospital and is never given as the only treatment for COVID-19.

Patients who are given remdesivir are also treated with other medications, including a corticosteroid agent (such as dexamethasone) and may also include other drugs that mitigate immune function (such as tocilizumab) and drugs that decrease your ability to form blood clots (such as low molecular weight heparin).

References

Burwick RM, Yawetz S, Stephenson KE et al. Compassionate Use of Remdesivir in Pregnant Women With Severe Coronavirus Disease 2019. Clin Infect Dis. 2021 Dec 6;73(11):e3996-e4004. doi: 10.1093/cid/ciaa1466. PMID: 33031500; PMCID: PMC7797739.

Lampejo T. Remdesivir for the treatment of COVID-19 in pregnancy. J Med Virol. 2021 Jul;93(7):4114-4119. doi: 10.1002/jmv.26986. Epub 2021 Apr 14. PMID: 33788273; PMCID: PMC8250519.

National Institutes of Health. Coronavirus disease 2019 (COVID-19) treatment guidelines. Retrieved December 26, 2021