Background: We systematically reviewed the safety and effectiveness of cannabis and cannabinoids treatment for Crohn's disease (CD) and ulcerative colitis (UC).
Methods: MEDLINE, Embase, WHO ICTRP, AMED, PsychINFO, CENTRAL, ClinicalTrials.Gov, and the European Clinical Trials Register were searched for relevant studies.
Main results: Five randomized controlled trials (3 CD and 2 UC studies, 185 participants) were included. One CD study (N = 21) showed 45% (5 of 11) of the cannabis cigarette group experienced clinical remission compared with 10% (1 of 10) of the placebo group (risk ratio [RR] 4.55; 95% CI, 0.63-32.56). Another CD study (N = 19) did not show significant rates of clinical remission. Forty percent (4 of 10) of participants in the cannabis oil group experienced remission compared with 33% (3 of 9) of the placebo group (RR 1.20; 95% CI, 0.36-3.97). A UC study (N = 60) did not have significant clinical remission rates. Twenty-four percent (7 of 29) of cannabis oil participants experienced remission compared with 26% (8 of 31) of placebo participants (RR 0.94; 95% CI, 0.39-2.25). A second UC study (N = 32) showed the effects on disease activity, C-reactive protein levels, and fecal calprotectin levels were uncertain. Adverse events were more prevalent in the cannabis groups for both CD and UC studies. GRADE analysis for the UC and CD studies ranged from very low to moderate.
Conclusions: In summary, no firm conclusions can be made regarding the safety and effectiveness of cannabis and cannabinoids in adults with CD and UC.
Keywords: Crohn’s disease; cannabinoids; cannabis; inflammatory bowel disease; ulcerative colitis.
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