Two authors independently screened search results, extracted data and assessed bias using the Cochrane risk of bias tool. The primary outcomes were clinical remission and relapse (as defined by the primary studies). Secondary outcomes included clinical response, endoscopic remission, endoscopic response, histological response, quality of life, C-reactive protein (CRP) and fecal calprotectin measurements, symptom improvement, adverse events, serious adverse events, withdrawal due to adverse events, psychotropic adverse events, and cannabis dependence and withdrawal effects. We calculated the risk ratio (RR) and corresponding 95% confidence interval for dichotomous outcomes. For continuous outcomes, we calculated the mean difference (MD) and corresponding 95% CI. Data were pooled for analysis when the interventions, patient groups and outcomes were sufficiently similar (determined by consensus). Data were analyzed on an intention-to-treat basis. GRADE was used to evaluate the overall certainty of evidence.
Cannabis and cannabinoids are often promoted as treatment for many illnesses and are widely used among patients with ulcerative colitis (UC). Few studies have evaluated the use of these agents in UC. Further, cannabis has potential for adverse events and the long-term consequences of cannabis and cannabinoid use in UC are unknown.
Cannabis is a widely used recreational drug that has multiple effects on the body via the endocannabinoid system. Cannabis contains multiple sub-ingredients called cannabinoids. Cannabis and cannabis oil containing specific cannabinoids can cause cognitive changes such as feelings of euphoria and altered sensory perception. However, some cannabinoids, such as cannabidiol, do not have a psychoactive effect. Cannabis and some cannabinoids have been shown to decrease inflammation in animal and laboratory models which suggests it may help people with ulcerative colitis. For example, cannabidiol is one such cannabinoid that has shown anti-inflammatory activity in mice.
We searched MEDLINE, Embase, WHO ICTRP, AMED, PsychINFO, the Cochrane IBD Group Specialized Register, CENTRAL, ClinicalTrials.Gov and the European Clinical Trials Register from inception to 2 January 2018. Conference abstracts and references were searched to identify additional studies.
The second study comparing two cannabis cigarettes (23 mg THC/day) to placebo cigarettes showed lower disease activity index scores in the cannabis group compared to the placebo group. C-reactive protein and fecal calprotectin levels (both measures of inflammation in the body) were similar in both groups. No serious side effects were reported. This study did not report on remission rates.
The researchers evaluated whether cannabis or cannabis oil (cannabidiol) was better than placebo (e.g. fake drug) for treating adults with active ulcerative colitis or ulcerative colitis that is in remission. The researchers searched the medical literature extensively up to 2 January 2018.
Another study also recorded dose ranges of 50 mg to 250 mg CBD capsules twice daily. Many participants were able to tolerate the higher dosage and saw improvements, though the study authors suggested that more research is needed.
CBD is best used as a supplemental therapy alongside conventional treatments recommended by your healthcare provider, as well as dietary modifications. As with any supplement or medication, talk with your healthcare provider before trying CBD.
One study found that participants with UC who took 50 milligrams (mg) of CBD oil twice a day, increasing to 250 mg per dose if needed and tolerated, experienced significant improvements in their quality of life. However, more research and follow-up studies are needed.
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As with many medications, it’s best to start with a lower dose and gradually increase the amount of CBD to determine the appropriate dosage.
Because CBD is still a relatively new therapeutic option for managing different health conditions, including inflammatory bowel diseases, there is currently no recommended standard dosage.
To date, CBD has only been approved by the Food and Drug Administration to treat epilepsy. As a result, there is no standard recommended dosage of CBD for treating ulcerative colitis.
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Although more research is needed, current study results show promise that CBD may be beneficial for treating symptoms of ulcerative colitis.