P448 Cannabis and cannabinoids for the treatment of inflammatory bowel disease: a systematic review and meta-analysis

Abstract

Inflammatory bowel disease (IBD) patients increasingly use complementary and alternative medicine such as cannabis and/or cannabinoids. Cannabinoids may have anti-inflammatory properties through interaction with the endocannabinoid system. We performed a systematic review with meta-analysis to assess the efficacy of cannabi(noid)s in treating IBD. We included randomised controlled trials (RCTs) and non-randomised studies (NRSs) analysing IBD patients of any age using cannabi(noid)s. Two reviewers searched MEDLINE, Embase and CENTRAL until 19 July 2018. A data extraction sheet included study characteristics, patient characteristics, intervention details, and disease activity scores. We assessed risk of bias with the Cochrane Risk of Bias tool and the Newcastle-Ottawa Quality Assessment Scale. Revman 5.3 computed relative risks (RR), mean differences (MD), and standardised mean differences (SMD) with a 95% confidence interval (95% CI) using the random-effects model. For the meta-analyses, only RCTs were included. The search identified 571 records of which 9 NRSs and 4 RCTs were eligible for inclusion. The meta-analysis included 100 randomised participants. Risk of bias was moderate to high. Cannabi(noid)s were not effective in inducing remission (RR = 1.29, 95% CI = 0.68–2.47; see figure). Statistical heterogeneity was low (I2 = 0%, p = 0.40). However, average disease activity score in the intervention group (SMD = 1.47, 95% CI = 1.00–1.94) was significantly different from the average disease activity score in the control group (SMD = 0.71, 95% CI = 0.31–1.15; p = 0.02, I2 = 81%). Effect on CRP and calprotectin was not significant (MD=0.50, 95% CI = −1.87–2.86; MD=−31, 95% CI = −162–101). Abdominal pain, general well-being, nausea, diarrhoea and poor appetite all improved with cannabi(noid)s on Likert-scales. Baseline quality of life was lower in patients using cannabis amongst cohort studies (MD = −0.64; 95% CI = −0.92 to −0.36) but improved significantly with cannabi(noid)s in a prospective NRS and two RCTs. Cannabi(noid)s seem ineffective in inducing remission in patients with IBD. However, IBD patients may benefit from cannabi(noid)s by improvement of symptoms and quality of life. Although statistical heterogeneity was low, studies were heterogeneous regarding patients and intervention and mostly included small numbers of patients. Larger uniform studies are needed. Additionally, the most effective formulation and dose as well as safety of cannabi(noid)s have to be further elucidated.