Rheumatoid Arthritis

Cannabinoids showed statistically significant effects on pain in 2 of 4 studies and on sleep in 2 studies, but with frequent side effects (dizziness, cognitive problems, drowsiness, nausea in about half of patients) and overall insufficient evidence for a recommendation.

Systematic review on cannabinoids in rheumatic diseases; k=4 short-term RCTs (n=203 total: 58 RA, 71 fibromyalgia, 74 osteoarthritis). In RA (n=58, 5 weeks THC/CBD): statistically significant effect on pain in 2 studies, sleep in 2 studies, quality of life in 1 study. High risk of bias in all 3 completed studies. Almost 50% of patients reported dizziness, cognitive problems, drowsiness and nausea. No serious side effects during the study period.

The findings on superiority of cannabinoids over controls (placebo, amitriptyline) were inconsistent; currently insufficient evidence for a recommendation.

Systematic review on cannabinoids for chronic pain of rheumatic diseases; k=4 RCTs (n=159 total: 71 fibromyalgia, 30 back pain, 58 RA). For RA: one 5-week study with THC/CBD (n=58). Superiority of cannabinoids over controls (placebo, amitriptyline) not consistently demonstrated. High risk of bias in 3 studies. Cannabinoids generally well tolerated despite bothersome side effects, safe during study duration. Insufficient evidence for a recommendation in rheumatic diseases.

Cannabinoids show safe and modest analgesic efficacy in neuropathic pain, with preliminary indications of efficacy in fibromyalgia and rheumatoid arthritis.

Systematic review on cannabinoids in chronic non-cancer pain; k=18 RCTs (neuropathic pain, fibromyalgia, rheumatoid arthritis, mixed chronic pain). 15 of 18 studies showed significant analgesic effects vs. placebo, several reported significant sleep improvement. No serious adverse effects. Adverse effects mostly mild to moderate, well tolerated, rarely leading to study discontinuation. Evidence for efficacy in neuropathic pain, preliminary evidence for fibromyalgia and RA. Excellent study quality.

Cannabis products may slightly reduce disease activity, but show little to no difference in pain reduction and may increase nervous system adverse events; evidence for serious adverse events very uncertain.

Umbrella review of k=26 systematic reviews, which together identified only 1 RCT on cannabis/cannabinoids in rheumatoid arthritis. Cannabis/cannabinoids may slightly reduce disease activity; show little difference in pain reduction; may slightly increase nervous system side effects. Evidence on serious adverse events very uncertain (GRADE: very low quality).

Sativex showed statistically significant improvements in pain on movement, pain at rest, sleep quality, DAS28 and the SF-MPQ pain component compared to placebo.

n=58 RA patients; Sativex (nabiximols, oromucosal) vs. placebo over 5 weeks: significant improvements in pain on movement, pain at rest, sleep quality, DAS28 and SF-MPQ pain component (all p<0,05); no significant effect on morning stiffness. First controlled cannabinoid RCT in rheumatoid arthritis.

12,6% of patients reported medical cannabis use; about half continued use, mainly for pain relief; 57% of users discontinued due to lack of effect, 28% due to side effects.

n=1.000 rheumatology patients (RA, OA, fibromyalgia) following cannabis legalisation in Canada; 51% reported cannabis use, most common motives: pain reduction (71%) and sleep improvement (50%); no intervention data, pure prevalence survey.

Observational studies and surveys suggest perceived benefits, but prospective studies and RCTs are rare and the evidence remains sparse.

Narrative overview on cannabis for rheumatic pain (RA, OA, fibromyalgia); summary of preclinical mechanisms (CB2 receptor, anti-inflammatory effects) and clinical data from observational studies; no systematic data extraction, expert opinion on evidence gaps.