Cannabis and cannabinoids do not improve rates of clinical remission or inflammation in patients with inflammatory bowel disease (IBD), but they do significantly improve patient-reported symptoms and quality of life, a meta-analysis found.
Researchers reviewed five randomized controlled trials and 15 nonrandomized studies analyzing use of cannabis or cannabinoids in patients with IBD. Patients could be self-identified or physician-diagnosed. The primary outcome was induction or maintenance of remission according to a validated tool for IBD, including the Harvey-Bradshaw Index, Crohn's Disease Activity Index, or Mayo Score for Ulcerative Colitis. Secondary outcomes included inflammatory biomarkers, symptom improvement, quality of life scores, and hospital outcomes. Results were published online July 14 by the Journal of Clinical Gastroenterology.
Induction of remission was available as an outcome measure in four of five randomized studies and in one of the nonrandomized studies. Researchers based estimates of efficacy on the four trials, which randomized 146 patients, of whom 52 achieved clinical remission. On the primary end point of induction of remission, the overall result was negative (risk ratio [RR], 1.56; 95% CI, 0.99 to 2.46). There was no evidence of statistical heterogeneity for the studies used to calculate the summary measure. One nonrandomized study found a significant benefit from the use of cannabinoids (RR, 6.50; 95% CI, 1.60 to 26.36) for the induction of remission. However, this result was based on a comparison of 13 users and only two nonusers.
Cannabis and cannabinoids were not found to affect inflammatory biomarkers; the formation of strictures, fistula, abscesses, anemia, and bowel obstruction; or the need for colectomy, authors noted. C-reactive proteins, fecal calprotectin, and endoscopic disease activity did not improve significantly in association with cannabinoids.
However, clinical symptoms (abdominal pain, general well-being, nausea, diarrhea, and poor appetite) that were assessed on Likert scales all improved with cannabis and cannabinoids. In the included cohort studies, baseline quality of life scores were lower in patients using cannabis but improved significantly with cannabis and cannabinoids. Length of hospital stay was shorter and risk of parenteral nutrition was lower in patients using cannabis, but there was no effect on other IBD complications.
This topic warrants further research, according to the study authors. “Until then, prescription of cannabi(noid)s should be issued with caution. However, it may be considered in patients with a low [quality of life] to improve symptoms, as an additive to evidence-based anti-inflammatory medication,” they wrote.