ABSTRACT
OBJECTIVE: Use of medical cannabis for improving symptoms of inflammatory bowel disease is increasing. However, reports on long-term outcomes are lacking. This prospective, observational study assessed the effects of licensed cannabis use among patients with inflammatory bowel disease. METHODS: Dose and mode of consumption, adverse events, use of other medications, and long-term effects were evaluated among 127 patients with inflammatory bowel disease using legalized medical cannabis. Blood count, albumin, and C-reactive protein were assessed before, 1 month, and at least 1 year after medical cannabis therapy was initiated. Questionnaires on disease activity, patient function, and signs of addiction were completed by patients and by a significant family member to assess its effects. RESULTS: The average dose used was 31 ± 15 g/month. The average Harvey-Bradshaw index improved from 14 ± 6.7 to 7 ± 4.7 (P < 0.001) during a median follow-up of 44 months (interquartile range, 24-56 months). There was a slight, but statistically significant, average weight gain of 2 kg within 1 year of cannabis use. The need for other medications was significantly reduced. Employment among patients increased from 65 to 74% (P < 0.05). We conclude that the majority of inflammatory bowel disease patients using cannabis are satisfied with a dose of 30 g/month. We did not observe negative effects of cannabis use on the patients' social or occupational status. CONCLUSIONS: Cannabis use by inflammatory bowel disease patients can induce clinical improvement and is associated with reduced use of medication and slight weight gain. Most patients respond well to a dose of 30 g/month, or 21 mg Δ9-tetra- hydrocannabinol (THC) and 170 mg Cannabidiol (CBD) per day.