Ulcerative Colitis

The effect of cannabis and cannabinoids on ulcerative colitis is uncertain; no reliable conclusions can be drawn regarding efficacy and safety.

Cochrane systematic review on cannabis/cannabinoids in ulcerative colitis (search up to 02.01.2018). No RCTs on efficacy in UC identified — the review could not pool effectiveness or safety data. Conclusion: insufficient evidence for cannabis therapy in UC at the time of publication.

Cannabinoids showed improvements in disease activity in Crohn's disease and quality of life in both IBD forms, but no significant effects on UC activity, endoscopic findings or inflammatory markers.

Meta-analysis across k=8 RCTs on cannabinoids in IBD (4 Crohn's, 3 UC, 1 both diseases). For UC: clinical disease activity not significantly improved (RR=-2,13; 95% CI -4,80 to 0,55; I²=90,3%). Improvement in quality of life for both Crohn's disease and UC (RR=1,79; 95% CI 0,92-2,66; I²=82,8%). No differences in endoscopic activity or inflammatory markers.

Phytotherapeutics show varying levels of evidence for different gastroenterological diseases: strong recommendation for peppermint oil in irritable bowel syndrome, recommendations for further phytotherapeutics in constipation and ulcerative colitis, but insufficient data for Crohn's disease and a need for further methodologically high-quality studies.

Systematic screening of phytotherapeutic recommendations in gastroenterological guidelines. For ulcerative colitis: Plantago psyllium as well as the combination of myrrh/chamomile flower extract/coffee charcoal as a complement for maintaining remission; 'open recommendation' for curcumin (induction and maintenance of remission). Cannabis-based medicines may be considered for abdominal pain/loss of appetite if standard therapy is ineffective; not for acute inflammation.

Cannabinoids did not induce clinical remission in IBD, but significantly improved symptoms and quality of life.

SR+MA on cannabinoids in IBD (k=20 studies: 5 RCTs + 15 non-randomised); n=146 randomised participants; clinical remission not achieved (RR=1,56; 95%-CI 0,99–2,46); however significant improvement in patient-reported symptoms (abdominal pain, well-being, nausea, diarrhoea, appetite) and quality of life.

Cannabis showed no significant benefit over placebo/standard therapy in clinical remission or response in Crohn's disease or ulcerative colitis.

Meta-analysis of cannabis in ulcerative colitis; k=1 RCT (n=60: 29 cannabis, 31 placebo); no difference in remission failure (RR 1.02, 95%CI 0.76-1.37) or response (RR 0.99, 95%CI 0.65-1.21); adverse events occurred in all cannabis patients (RR 1.28, 95%CI 1.05-1.56); GRADE evidence low to very low.

Primary endpoint (remission rate) not achieved (CBD 28% vs. placebo 26%), but secondary analyses showed advantages of the CBD-rich extract for Mayo scores and subjective parameters.

n=29 ulcerative colitis, 10 weeks CBD-rich cannabis extract (2×50 mg CBD orally) vs. placebo; no significant difference in the primary endpoint (clinical remission: 28% CBD vs. 26% placebo, p=0.97); quality of life (IBDQ) improved non-significantly (p=0.36); well tolerated.

Cannabis led to clinical remission and improved quality of life, but not to significant improvement in endoscopic scores or inflammation markers.

n=32 active ulcerative colitis, cannabis cigarettes (23% THC, 0.5% CBD) vs. placebo over 8 weeks; clinical remission higher in cannabis group (28% vs. 26%, n.s.), no differences in endoscopic remission, symptom score improvement in both groups; primary endpoint not met.

Cannabis users with UC showed lower rates of colectomy (4,4% vs 9,7%), a trend toward fewer bowel obstructions, and shorter hospital stays (4,5 vs 5,7 days).

Propensity-score-matched retrospective cohort study from the NIS database (2010-2014); n=596 (298 cannabis users vs. 298 non-users) with hospitalized ulcerative colitis. Cannabis users had a significantly lower colectomy rate (4,4% vs. 9,7%, p=0.010), a trend toward fewer bowel obstructions (6,4% vs. 10,7%, p=0.057), and a shorter hospital length of stay (4,5 vs. 5,7 days, p<0.007).

Cannabis showed improvements in UC and CD scores and quality of life in studies, but the authors warn of deficiencies in standardisation and call for randomised controlled trials before therapeutic recommendations can be given.

Narrative review on cannabis and cannabinoids in chronic inflammatory bowel diseases (IBD); discusses mechanisms of action via the endocannabinoid system, anti-inflammatory effects and preclinical/clinical data on Crohn's disease and ulcerative colitis; no systematic meta-analysis.