Opioid reduction in patients with chronic non-cancer pain undergoing treatment with medicinal cannabis.

INTRODUCTION: Opioid sparing by co-prescription of cannabinoids may enable patients to reduce their opioid consumption prescribed for chronic benign pain. METHODS: One cohort attending a small private pain clinic (N = 102), already taking opioids, was co-prescribed cannabinoids and another cohort (N = 53) attending a separate pain clinic nearby received only opioids. The two groups were studied prospectively for a year before their drug consumption was assessed. RESULTS: At baseline, median opioid consumption was 40 mg/day in both cohorts. Medicinal cannabis was administered daily in an oil formulation usually starting at 2.5 mg/day and was titrated to maximize benefits. At 12 months, the median dose contained 15 mg delta-9-tetrahydrocannabinol and 15 mg cannabidiol. At one-year follow-up, 46 of 102 cases had dropped out compared with only one of 53 controls. Opioid consumption had decreased significantly at one-year follow-up, the final median dose being lower in cases (2.7 mg/day) than controls (42.3 mg/day) (p < 0.05 in an intention-to-treat analysis). Disability and insomnia had also decreased in cases. CONCLUSION: The introduction of cannabinoids can produce useful reductions in opioid consumption in real-world settings, with additional benefits for disability and insomnia. However, this treatment is tolerated by only a subgroup of patients. CLINICAL AUDIT REGISTRATION: https://www.anzctr.org.au/ identifier is ACTRN12621000875808.