Medical Cannabis is being prescribed within an increasing number of jurisdictions across the world. This is in response to a growing evidence base, reduction of stigma, and lowering of financial barriers. Whilst much more is left to be achieved on all fronts, Canada was one of the first countries to make medical cannabis available as an option for a wide range of conditions. As a result, many countries look to the Real-World Evidence (RWE) published by Canadian physicians to benchmark their clinical practice.
Medical cannabis describes a broad range of pharmaceutical products derived from the cannabis plant and can come in many different formulations (oils, capsules, dried flower). The two most prominent pharmaceutical ingredients which form the backbone of any therapy include cannabidiol (CBD) and tetrahydrocannabinol (THC). However, there is limited data published on specific products in real-world settings. A recent study published in the Journal of Cannabis Research aimed to assess changes in symptoms after initiation of CBD-rich medical cannabis.
The study included patients prescribed CBD-rich medical cannabis products. These products are defined as containing 0.5-1mg/ml of THC and 20-25mg/ml of CBD. Patients were aged 18 years or older.
Adjustments were made at each time period according to lack of effectiveness, presentation of adverse effects, or social or economic barriers.
Changes in symptom severity were assessed according to The Edmonton Symptom Assessment Scale-revised version (ESAS-r), which is a validated scale to assess symptom burden developed for use in oncology and palliative care. The scale from is a rating from 0-10 according to the severity of symptoms. The scale assesses physical symptoms (pain, tiredness, nausea, drowsiness, lack of appetite, shortness of breath), emotional symptoms (depression and anxiety), and well-being assessment.
Changes were assessed at first and second follow up from baseline. In addition, changes were compared between those with initially mild and moderate-severe symptoms.
1095 patients seen during study period over two years, with 715 eligible for the study according to inclusion criteria. Of these, 279 patients had available scores for the first follow up period. Patients received medical cannabis for the following reasons.
- 210 (75%) for chronic pain
- 19 (7%) for cancer related symptoms
- 21 (7.5%) for neurological conditions
- 8 (2.9%) for arthritis
- 10 (3.6%) for gastrointestinal conditions
- 3 (1.1%) for anxiety or depression
Across all patients’ pain scores showed a significant improvement from baseline to each follow up. Those patients with mild pain, experienced an increase in their pain levels. Anxiety levels significantly improved at each follow up period, however similar to pain, those with mild anxiety levels actually increased following medical cannabis. Symptoms of low mood improved over each follow up period across all patients. Finally, patients experienced a significant improvement in their total wellbeing scores up until final assessment.
This study on CBD-rich products demonstrated an association with improvements in pain, anxiety, depression, and overall well-being after initiating medical cannabis. However, there appears to be a. divergence of response whereby those with mild symptoms do not benefit or indeed have worse outcomes compared to those with more severe symptoms.
These findings have implications for clinical practice and suggest a need for closer evaluation for those with more mild symptoms to see who may be more likely to benefit or not from medical cannabis.