By Pat Anson, PNN Editor

Medical cannabis has been legal in the United Kingdom since 2018, but we’re only now getting the first evidence on the effectiveness of cannabis oil for UK chronic pain patients.

One hundred ten patients enrolled in the UK Medical Cannabis Registry reported significant improvements in their pain, discomfort and sleep quality after one, three and six months of treatment with cannabis oil. There was also statistically significant improvement in their health-related quality of life.

Due to strict rules, it is difficult to get a prescription for medical cannabis from the UK’s National Health Service. Patients can only be prescribed cannabis when conventional therapy has not provided adequate relief for conditions such as pain, anxiety and multiple sclerosis.

Most of the patients (65%) in the study had never used cannabis before. Their most common primary diagnosis was chronic non-cancer pain (48%), followed by neuropathic pain (24%) and fibromyalgia (16%).

“With the increasing number of prescriptions for medical cannabis in the UK, capturing patient outcomes and real-world evidence is essential for wider understanding and appropriate access for eligible patients,” Dr. Simon Erridge, head of research at Sapphire Medical Clinics, said in a statement.

“This research is the first of its kind in Europe and we continue to review condition and product-specific outcomes via the UK Medical Cannabis Registry. Though this is still observational data it will inform critical future research including randomised controlled trials.”

Sapphire Medical Clinics created the registry and surveyed patients to help fill some of the gaps in knowledge about medical cannabis. The findings were recently published in the Journal of Clinical Pharmacology.

“Despite promising preclinical data, there is a paucity of high-quality evidence to support the use of CBMPs (cannabis-based medicinal products). The evidence base, while broad, is inconclusive, variable across chronic pain types, and thus insufficient to inform guidelines, funders, and licensing agencies,” researchers said.

The cannabis oil used in the study is made by Adven, a subsidiary of Curaleaf International, Europe’s largest independent cannabis company. The median CBD dose was 20 mg per day, while the median THC dose was 1 mg per day, giving the oil a CBD/THC ratio of 20 to 1. Adverse events such as nausea, dizziness and constipation were reported by nearly a third of patients, with most symptoms being mild or moderate.

Sapphire Medical Clinics is planning further studies of cannabis products as more participants enroll in its cannabis registry.

‘Mother of All Cannabinoids’

Another study conducted in the U.S. found that people who use cannabis products that are rich in cannabigerol (CBG) reported significant improvement in their pain, anxiety, depression and insomnia.

CBG is known as the “mother of all cannabinoids” because it rapidly converts into THC and CBD. Only trace amounts of CBG are found in most cannabis plants, but in recent years cultivated strains rich in CBG have been grown in the Pacific Northwest.

Researchers at Washington State University and the University of California Los Angeles surveyed 127 people who self-identified as consumers of CBG-dominant cannabis. Most reported their pain and other symptoms were “very much improved” or “much improved” by CBG.

About 75% said CBG-predominant cannabis was superior to conventional medications for chronic pain, depression, insomnia and anxiety. A little over half reported minor side effects such as dry mouth, sleepiness, increased appetite, and dry eyes. Most reported no withdrawal symptoms.

“This is the first patient survey of CBG-predominant cannabis use to date, and the first to document self-reported efficacy of CBG-predominant products, particularly for anxiety, chronic pain, depression, and insomnia. Most respondents reported greater efficacy of CBG-predominant cannabis over conventional pharmacotherapy, with a benign adverse event profile and negligible withdrawal symptoms,” researchers reported in the journal Cannabis and Cannabinoid Research. 

“This study demonstrates that CBG-predominant cannabis and related products are available and being used by cannabis consumers and demonstrates the urgent need for randomized controlled trials of CBG-predominant cannabis-based medicines to be studied rigorously to assess safety and efficacy.”

Preliminary research suggests CBG has antibacterial properties and might be useful in treating inflammatory bowel disease (IBD), glaucoma, Huntington’s disease and some forms of cancer.