Effect of cannabis on opioid use in patients with cancer receiving palliative care.

OBJECTIVE: Opioids are the primary therapy for cancer-related pain in patients receiving palliative care. More states are legalizing medical cannabis, which may provide a pain management alternative for some of these patients. This study aimed to estimate the effect of cannabis on opioid use in patients with cancer receiving palliative care.

METHODS: This was a retrospective cohort study of patients with cancer at an academic medical center palliative care clinic. The primary outcome was change in morphine equivalent daily dose (MEDD) from baseline to 84-day follow-up in the cannabis plus opioid group compared to that in the opioid-only group.

RESULTS: A total of 83 patients were included: 61 in the opioid monotherapy group and 22 in the cannabis plus opioid group. An increase in MEDD from the baseline to 84 days was seen in both the opioid monotherapy and opioid plus cannabis group (28.8 vs. 10.8); however, the study lacked power to detect a statistical difference.

CONCLUSION: A possibly meaningful difference in MEDD increase was seen when comparing the opioid monotherapy group with the opioid plus cannabis group. However, the study was not powered to test this hypothesis; the findings suggest that further research is warranted to determine the impact of cannabis use on opioid dosing in patients receiving palliative care for cancer.