Fibromyalgia is a chronic pain condition characterised by generalised pain lasting at least three months. The condition is often also accompanied by tender areas and symptoms, such as fatigue, sleep disturbance, and cognitive problems, often termed “fibro fog”. Data shows that over half of patients with fibromyalgia also have comorbid insomnia and depressive symptoms. Living with fibromyalgia can therefore be incredibly challenging
There is no cure for fibromyalgia, with treatments instead focusing on alleviating symptoms and improving function and quality of life.
At Curaleaf Clinic, we are committed to contributing to the body of clinical evidence for medical cannabis. We are proud to share the key findings from a significant new study published in Clinical Rheumatology, which analysed data from our own UK Medical Cannabis Registry.
The UK Medical Cannabis Registry
The UK Medical Cannabis Registry was established by Curaleaf Clinic in 2019 to gather real-world data from patients prescribed medical cannabis for a wide range of conditions, including fibromyalgia. A previous analysis of data from fibromyalgia patients enrolled on the UKMCR found that medical cannabis was associated with changes in fibromyalgia-specific symptoms, as well as sleep, anxiety, and health-related quality of life at up to 12 months.
The current analysis aimed to build on these findings to further assess the outcomes of fibromyalgia patients prescribed medical cannabis.
The study assessed patient-reported outcome measures (PROMs) recorded at baseline (prior to initiation of medical cannabis treatment), 1, 3, 6, 12, and 18 months. PROMs included:
- The 12-point Fibromyalgia Symptom Severity scale – evaluates three core symptoms (fatigue, sleep, cognitive symptoms) and additional symptoms, including abdominal cramps, depression, and headache.
- The 19-point Widespread Pain Index (WPI) – assesses pain/tenderness across 19 body areas.
- The EQ-5D-5L scale – evaluates five domains of health-related quality of life: anxiety/depression, mobility, pain/discomfort, self-care, and usual activities.
- The Generalised Anxiety Disorder scale (GAD-7) – assesses the severity of anxiety symptoms.
- The Single-Item Sleep Quality Scale (SQS) – allows patients to rate their overall sleep quality on a scale of 0-10.
- Patient Global Impression of Change (PGIC) – a 7-point numerical rating scale, allowing patients to report their perceived improvement.
Key Findings of the Analysis
The study included 497 patients with a primary diagnosis of fibromyalgia from the UKMCR.
The mean age was 44.66 years, and 68.61% of patients were female, which is in line with typical demographics for fibromyalgia.
Patient-Reported Outcome Measures
- Fibromyalgia-specific outcomes: Changes were seen in Fibromyalgia Symptom Severity Scale and Fibromyalgia WPI scores across all follow-up points compared to baseline.
- EQ-5D-5L outcomes: Patients reported changes in all domains of the EQ-5D-5L from baseline up to all follow-up points, including anxiety, pain and discomfort, mobility, self-care, and usual activities.
- Sleep outcomes: Patients also reported changes in sleep quality at all follow-up points.
Patient and Medication-Specific Factors
The study identified specific factors that were associated with a greater likelihood of experiencing a change in fibromyalgia-specific symptoms:
- Higher Cannabidiol (CBD) Doses: Patients prescribed a higher CBD dose were more likely to see an improvement in both the Fibromyalgia Symptom Severity score and the WPI.
- Previous Cannabis Use: Being a current user of cannabis at baseline was associated with an increased likelihood of change in the fibromyalgia scales.
- Age: Patients in the 41–50 years age group also had increased odds of change.
Adverse Events
We believe in providing a balanced view of treatment. This study is an important part of understanding potential side effects:
- Prevalence: A total of 227 patients (45.67%) reported 2100 adverse events. This is a higher proportion than observed in other patient cohorts from the UK Medical Cannabis Registry.
- Severity: Crucially, the majority of adverse events (85.33%) were classified as mild-to-moderate. Only 2 adverse events (0.10%) were life-threatening or disabling.
- Most Common Adverse Events: The three most commonly reported adverse events were:
- Fatigue (30.78%)
- Dry mouth (27.57%)
- Concentration impairment (26.16%)
Why the higher incidence? The authors suggest that the higher rate of adverse events in fibromyalgia patients might be related to the condition’s mechanism of central sensitisation, which makes the nervous system more sensitive to new stimuli, including medical cannabis.
What Does This Mean for You?
This large-scale, real-world analysis provides valuable evidence on the use of medical cannabis in patients with fibromyalgia which has not responded to first-line medications.
While this study is promising, it is a case series and cannot prove that the improvements were caused solely by medical cannabis. The authors call for more rigorous randomised controlled trials to confirm these results.
If you want to understand whether medical cannabis is right for you, our specialist doctors can review your case and discuss how these findings may relate to your personal health goals, particularly if you’ve tried first-line treatments.