COVID-19 Update

CADTH is committed to supporting Canada’s health care decision-makers through this challenging and uncertain time.

Our COVID-19 Evidence Portal contains the latest COVID-19 information from CADTH and other respected organizations. Content is updated daily to reflect the rapidly changing and increasing international scientific evidence related to this disease.

The following is a summary of the most recent information posted to our COVID-19 portal.


Chloroquine or Hydroxychloroquine to Prevent or Treat COVID-19

  • This report (last updated on April 23, 2021) reviews the current scientific evidence on the potential benefits and harms of chloroquine and hydroxychloroquine for the prevention or treatment of COVID-19.
  • The current evidence does not support the use of high-dose chloroquine because of concerns of cardiac toxicity and increased lethality relative to low-dose chloroquine.
  • The results of the included studies also do not support the use of hydroxychloroquine for treating patients with mild, moderate, or severe COVID-19, nor does hydroxychloroquine appear to prevent COVID-19 post-exposure.

COVID-19 News

Visit our COVID-19 news page to stay on top of all the emerging information we are monitoring and updating.

CADTH Literature Searching Tools

To help conduct your COVID-19–related literature searches, see our COVID-19 Search Strings and our COVID-19 Grey Literature Resources.

Additional Resources

CADTH is pleased to showcase additional COVID-19 resources from our partner organizations and the Canadian federal, provincial, and territorial governments’ health jurisdictions:

  • Pan-Canadian Health Organizations
  • Federal, Provincial, and Territorial Information


Canadian ministries and departments of health, publicly funded organizations responsible for health service delivery, and clinical society stakeholders are encouraged to submit a request or contact their CADTH Liaison Officer. We’re here to help.

The CADTH Weekly COVID-19 Update is intended to keep you informed about the latest information posted on the CADTH COVID-19 portal.