COVID Therapies for Hospitalized Patients

Editor: Lauren Dayes

Over the course of the past year, sights have been set on the development of vaccines targeting the SARS-CoV-2 virus. However, there have also been several therapies developed to treat the virus in hospitalized patients. With new evidence emerging almost every day, plenty of medications have been tried, to no avail. Below, we will be summarizing four treatments successfully used in current practice, in certain parts of Canada.

Dexamethasone

The first, and most prescribed, medication administered to hospitalized patients affected by COVID-19 is dexamethasone. As you may have guessed, this drug was not developed with COVID-19 in mind; however, it has become a mainstay in treating these patients. While not approved by Health Canada for this purpose, the pertinent off-label prescribing information is outlined below.

Mechanism of Action: Mitigate the inflammatory response elicited by viral infection to reduce damage to the patient’s lungs and other organs.

Indication: Adults with symptoms persisting longer than 5 days and SpO2 ≤ 94% on room air or supplemental oxygen or ECMO.

Dosage: 6 mg PO/NG/IV daily x10 days or until hospital discharge (whichever is earlier)

Tocilizumab

This drug has not been approved by Health Canada for the treatment of COVID-19, nor is it under review for this indication. Prior to the COVID-19 pandemic, it was most often prescribed to patients with rheumatoid arthritis.

Mechanism of Action: A monoclonal antibody inhibiting the binding of interleukin-6 to its receptor, preventing hyperinflammation associated with severe COVID-19.

Indication: Early severe COVID-19 characterized by SpO2 ≤ 92% on room air or supplemental oxygen and a C-reactive protein (CRP) >75 mg/L.

Dosage: 8 mg/kg IV (up to 800 mg) x 1 dose administered over an hour. Patients living in areas where parasitic infections are endemic should also be administered ivermectin prophylactically.

Remdesivir

This drug was approved in July 2020 for the treatment of hospitalized COVID-19 patients. Unlike tocilizumab, there are currently no other authorized indications for remdesivir in Canada.

Mechanism of Action: Inhibits the replication of viral genetic material by interacting with RNA polymerases.

Indication: Adults and youth aged ≥12 years (≥40 kg) with severe COVID-19 and pneumonia requiring supplemental oxygen.

Dosage: 200 mg IV x 1 day, then 100 mg IV x 4 days

Bamlanivimab

This drug was approved by Health Canada in November 2020 with terms and conditions and marked the first drug specifically targeting the SARS-CoV-2 virus. Of note, the emergency use authorization for bamlanivimab in the USA was revoked in April 2021 following reports of resistance in certain SARS-CoV-2 variants. With the emergence of the Delta variant in various regions in Canada, it is unclear whether bamlanivimab will remain a viable treatment option.

Mechanism of Action: Monoclonal antibody that attaches to the SARS-CoV-2 spike protein, thereby preventing viral entry into cells. It is what is known as a “neutralizing antibody” and works by reducing the number of viral particles available for entry into host cells.

Indication: As part of the terms and conditions of approval, patients need to be enrolled in a clinical trial to receive this drug. The criteria for use include age ≥12 (and weight ≥40 kg) with mild-moderate COVID-19 at high risk of progressing to severe illness (i.e. have comorbidities).

Dosage: One-time IV infusion of 700 mg over one hour. Patients should be monitored for one hour after receiving the medication.

Takeaways

While this was a very broad overview of the most common treatments available to patients hospitalized with COVID-19, I thought it was important to highlight some of the truly amazing advances that have been made not just in the prevention of COVID-19, but also the treatment for those who may not be eligible for the vaccine or the breakthrough cases that will inevitably follow mass vaccinations. As new variants arise, and new challenges present themselves, it is an exciting area of research.

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References

1. Bamlanivimab in the treatment of outpatients with COVID-19: a critical appraisal of the BLAZE-1 trial. Ottawa: CADTH; January 2021. (CADTH Health Technology Review).

2. Bhimraj A, Morgan RL, Shumaker AH, et al. Infectious diseases Society of America guidelines on the treatment and management of patients with COVID-19. Updated November 2020: Available at: https://www.idsociety.org/practice-guideline/covid-19-guideline-treatment-and-management/#toc-10

3. Public Health Agency of Canada. Clinical management of patients with COVID-19: Second interim guidance. 2020 Aug 17. Available at: https://canadiancriticalcare.org/resources/Documents/AMMI-CCCS-PHAC-clinical-guidance-Aug21-EN-FINAL.pdf