Potential of cannabis in treating Long Covid warrants further research

The role of cannabis-based medicines in treating the symptoms of Long Covid warrants further investigation, according to a new review.

UK researchers say existing evidence supports the use of cannabis as a potential treatment for Long Covid, including for symptoms of sleep disturbance, fatigue, pain and anxiety. 

Long covid, which refers to persistent or new symptoms that develop at least eight weeks following an initial Covid-19 infection, continues to affect the lives of millions of people and presents a significant need for new treatment options. 

According to the Office for National Statistics (ONS), an estimated 2 million people in the UK were experiencing self-reported Long Covid in January 2023, with symptoms found to adversely affect the day-to-day activities of 1.5 million of those.

Long Covid can affect people differently and may lead to a number of different symptoms , with fatigue is often reported as the most common symptom, followed by difficulty concentrating, shortness of breath and muscle ache, as well as sleep disturbances, anxiety and depression. 

Given the growing evidence base to support the use of cannabis-based treatments in indications such as chronic pain, anxiety and sleep disorders, there has been interest in exploring its potential to offer some relief for Long Covid patients. 

Evidence for potential of cannabis in Long Covid 

In a newly-published review of current studies, researchers at Drug Science have identified ‘multiple lines of evidence’ to support the use of cannabis-based medicines in Long Covid.

According to the authors, previous studies have reported the potential of cannabinoids for alleviating chronic pain – including reducing the length and frequency of headaches and migraines common in Long Covid – as well as symptoms of anxiety, depression and sleep disturbances.

They note a lack of research specifically looking at the effects of cannabis on fatigue, however in other conditions where this symptom is common, such as fibromyalgia, observational studies have reported reductions in fatigue as well as decreases in pain, headaches, fatigue, anxiety, and nausea.

Many patients with Long Covid also experience cognitive dysfunction and some small studies indicate that cannabis, specifically, high-CBD products may help improve cognitive performance.

Other research suggests that cannabis-based medicines may have potential to reduce inflammation caused by Covid-19 infection, as an antiviral agent, and in managing symptoms of dysautonomia – a disorder of the autonomic nervous system, which has been linked to Long Covid. 

Dysautonomia can cause symptoms such as palpitations, fatigue, sleep difficulties, cognitive impairment, breathlessness, and dizziness and is also present in conditions such as diabetes, Parkinson’s and fibromyalgia for which medical cannabis has shown promise, according to the paper. 

The importance of further research 

The authors say their findings highlight the importance of further research being carried out in cannabis-based medicines and long covid, including looking at real-world data alongside randomised control trials (RCTs). 

They conclude: “Given current evidence that the use of CBMPs [cannabis-based medicinal products] may ameliorate symptoms in Long COVID, there is rationale to further explore how cannabinoids might interact with the SARS-Cov-2 virus and how CBMPs may work in Long COVID patients. There is value in the role of RWE [real world evidence] in the context of CBMPs and Long COVID to progress much-needed research in this large population of patients, contributing to not only the evidence base for Long COVID but also current knowledge of CBMPs.”

Last year, Drug Science carried out an open-label Phase 2 feasibility study looking at the safety and tolerability of a CBD-dominant oil on a small number of long covid patients in the UK.

The product was found to be ‘well tolerated’ with ‘no serious adverse events’.

Speaking about the study at Cannabis Europa earlier this year, Hannah Thurgur, senior research officer at Drug Science and co-author of the review, said further placebo-controlled trials would be beneficial to study the efficacy of the product in more detail, alongside collecting more real-world data on the use of cannabis medicines in Long Covid patients. 

“We are in a world now where medical cannabis is available across different jurisdictions, so it’s really important that real-world evidence is collected to really understand what subgroups of patients this could potentially help, especially with Long Covid and other post-viral fatigue syndromes,” said Thurgur.

“Wearable technology could also be used to look at specific markers such as heart rate variability which could potentially be used to guide treatment.”

She added: “It’s about having a multi-pronged approach to gather the best data possible.”

Clinical experience of cannabis and Long Covid

Dr Dani Gordon, a specialist in integrative cannabinoid medicine, also took part in the discussion and shared her experience of treating long covid and post-viral fatigue patients in her clinic. 

“I have been treating chronic complex conditions using integrative cannabinoid medicine for over a decade,” she explained. 

“Post-viral, or chronic fatigue, is a bucket of conditions because it’s so complex and everyone is slightly different. There’s immune dysfunction, microbiome dysfunction, increased intestinal permeability, or leaky gut, and then you may have some endocannabinoid system dysregulation, which is probably why cannabinoids do help. They also seem to have an anti-inflammatory factor and an immunomodulatory effect, as well as the brain networking component.”

Dr Gordon continued: “Cannabis really is a personalised medicine in the context of an illness that needs to be completely personalised to the patient – and that’s why it’s so difficult for conventional medicine to cope with these conditions. All of the patients who come to me have already been to the Long Covid clinics, they have been taught about pacing and they have tried CBT [cognitive behavioural therapy]. These are helpful to some extent, but it’s not helping with the underlying mechanisms of their illness and that’s really where we need more therapies and more research.”

Watch the full panel discussion on cannabis for Long Covid here