Safety and Efficacy of Medical Cannabis in Fibromyalgia
Iftach Sagy, Lihi Bar-Lev Schleider, Mahmoud Abu-Shakra and Victor Novack
Journal of Clinical Medicine, 2019, 8, 807
doi : 10.3390/jcm8060807
Background : Chronic pain may be treated by medical cannabis. Yet, there is scarce evidence
to support the role of medical cannabis in the treatment of fibromyalgia. The aim of the study was to
investigate the characteristics, safety, and eectiveness of medical cannabis therapy for fibromyalgia.
Methods : A prospective observational study with six months follow-up period based on fibromyalgia
patients who were willing to answer questionnaire in a specialized medical cannabis clinic between
2015 and 2017.
Results : Among the 367 fibromyalgia patients, the mean age was 52.9 15.1, of whom 301 (82.0%) were women. Twenty eight patients (7.6%) stopped the treatment prior to the six months follow-up. The six months response rate was 70.8%. Pain intensity (scale 0–10) reduced from a median of 9.0 at baseline to 5.0 (p < 0.001), and 194 patients (81.1%) achieved treatment response. In a multivariate analysis, age above 60 years (odds ratio [OR] 0.34, 95% C.I 0.16–0.72), concerns about cannabis treatment (OR 0.36, 95% C.I 0.16–0.80), spasticity (OR 2.26, 95% C.I 1.08–4.72), and previous use of cannabis (OR 2.46 95% C.I 1.06–5.74) were associated with treatment outcome. The most common adverse eects were mild and included dizziness (7.9%), dry mouth (6.7%), and gastrointestinal symptoms (5.4%).
Conclusion : Medical cannabis appears to be a safe and eective alternative for the treatment of fibromyalgia symptoms. Standardization of treatment compounds and regimens are required.
Keywords : medical cannabis; fibromyalgia; quality of life; chronic pain
Fibromyalgia is a common syndrome of chronic pain, often accompanied by sleeping disturbances, cognitive impairment, and psychiatric and somatic symptoms [1,2]. The prevalence of fibromyalgia is 2–8% of the entire population, and it is the most common reason for generalized pain among working
age women worldwide [3,4]. Therapy for fibromyalgia is challenging and based on a multidisciplinary approach. Patients with fibromyalgia may respond to a combination of pharmacological (e.g., tricyclic antidepressants, serotonin/norepinephrine reuptake inhibitors, and anticonvulsants) and non-pharmacological interventions (e.g., aerobic exercise, cognitive-behavioral therapy, and rehabilitation programs) .
On the other hand, utilization of opioids was found to be associated with poorer symptoms and poorer functional and occupational status compared to nonusers . Medical cannabis represents a promising therapeutic option for fibromyalgia patients due to its effectiveness and relatively low rate of serious adverse effects [7,8]. Although the identification of cannabinoid receptors and their endogenous ligands has triggered a large body of studies, there is a paucity of large-scale and prospective clinical trials regarding their role in fibromyalgia . Only a handful of studies have examined the effect of medical cannabis on fibromyalgia. These studies had rather small sample sizes (31–40 subjects) and a short duration of follow up, which makes the generalizability of the results questionable [10–12]. In the current analysis of the prospective registry, we aim to investigate the safety and effectiveness of fibromyalgia patients receiving medical cannabis.