The Complicated Relationship Between COVID-19 and Cannabis: A Year in Review

With false claims circulating about the effectiveness of cannabis to treat COVID-19 and studies rapidly pouring out of labs and hospitals, it is challenging to make sense of it all. AJEM spoke with leading cannabis researchers and physicians to reflect on what we’ve learned after a year of COVID-19. In short, it’s complicated. Medical cannabinoid therapy can both hurt and help patients who are infected with COVID-19, and the effect seems to be highly dependent on the patient’s stage of COVID-19 infection.

Some researchers and physicians say they are concerned that cannabis, especially
when taken at high doses, might be harmful to those who are infected with the novel coronavirus, particularly anyone at high risk for a severe response to the virus. Patients may be especially vulnerable in the early stages of COVID-19 infection when the immune system must mount a strong response, leading some experts to particularly worry about those with underlying conditions who smoke and vape.

Others point to emerging research showing that cannabinoids may be beneficial in late-stage severe disease during a cytokine storm. They are hopeful that medical cannabis may play a role in reducing the risks of SARS-CoV-2 infection by modulating angiotensin converting enzyme 2 (ACE2) expression, which has been shown to control the novel coronavirus’ access to a human cell.

The vaccination period is also unclear. Should medical cannabis physicians be advising patients to reduce cannabis consumption during vaccination to ensure the body is able to develop effective antibodies?

“It’s a complex situation. We don’t have good clinical end point data to say this is not good or this is good,” said Barry Mennen, MD, an urgent care and family physician
in Maryland who prescribes medical marijuana to patients.

Medical Cannabis Physicians Advise Caution
Dr. Mennen is asking his patients to reconsider their medical cannabis use during the ongoing crisis, saying there is compelling evidence from other viral infections indicating that medical cannabis could potentially increase the risk for a severe response. He is most concerned about patients who have comorbidities that put them at risk for COVID-19, or those who live or work in situations with a high risk for exposure to the virus.

“What we can say is that it’s probably prudent at this point to either reduce or end cannabinoid use while the pandemic is still occurring, especially for patients who are
more vulnerable to health issues.”

There is insufficient evidence that medical cannabis puts all patients in jeopardy, he said. “All I can say is, the best data we have suggests there could be an extra risk.”
With medical cannabis, it is difficult to isolate how each of the various components that go into a single product can influence the immune system.

Medical cannabis that uses a full extract oil or flower product contains hundreds of cannabinoids, along with other bioactive compounds like flavonoids and terpenoids.
Together, these may have an immune-modulating effect; however, it is difficult to know precisely how they affect the immune system, particularly in the context of a new and poorly understood virus, said Dani Gordon, MD, a UK-based physician and an expert in cannabis medicine.