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Study breakdown

Medical cannabis patients filled slightly fewer opioid prescriptions over 6 months

Retrospective CohortLow evidence
The takeaway

Among 68 Israeli chronic pain patients, opioid prescription fills decreased modestly after starting medical cannabis, but no changes were seen in other medications or healthcare service use.

Pain medicine clinicians, medical cannabis researchers, and policymakers evaluating cannabis as an opioid-sparing strategy.

68 patients; small but significant reduction in opioid prescriptions over 6 months

What the researchers found

Patients filled fewer opioid prescriptions at 6-month follow-up compared to the 6 months before starting medical cannabis. The reduction was statistically significant but of small effect size. No changes in non-opioid medications or healthcare utilization.

Why it matters

The opioid-sparing potential of medical cannabis is one of its most cited justifications. This small study adds to the mixed evidence, finding a real but modest reduction.

The numbers in context

68 patients. Opioid prescriptions decreased from baseline to 6-month follow-up with small effect size. No significant changes in other medication types or healthcare service utilization.

How the study worked

Retrospective cohort study using medical records of 68 Israeli patients with chronic pain who initiated medical cannabis. Compared prescription fills and healthcare service use 6 months before vs. 6 months after starting treatment. Paired t-tests for within-patient comparisons.

What this study cannot tell us

Very small sample (68 patients). No control group. Retrospective design using medical records. Cannot account for other changes in pain management. Small effect size questions clinical significance. Israeli medical cannabis system differs from other countries.

How to read the evidence

Small retrospective cohort with no control group. Preliminary evidence only.

When this study was published

Published 2023.

The bigger picture

The opioid-sparing narrative around medical cannabis is compelling but the evidence remains mostly observational and small-scale. Definitive answers require randomized trials that can separate cannabis effects from regression to the mean and placebo.

Questions still open

  • Would a randomized trial confirm the opioid-sparing effect? Is the small reduction clinically meaningful for individual patients? Do certain pain conditions show larger opioid-sparing effects than others?

Common questions

Does medical cannabis reduce opioid use?
This small study found a modest reduction in opioid prescriptions after patients started medical cannabis, but the effect was small. Without a control group, it is impossible to know whether cannabis caused the reduction or whether other factors (like natural pain fluctuation or changing prescriber behavior) explain the change.
Did medical cannabis reduce overall healthcare use?
No. While opioid prescriptions decreased slightly, there were no significant changes in non-opioid medication fills or healthcare service utilization, suggesting the impact of medical cannabis on broader healthcare costs may be limited.

Read the original research

Opioid and healthcare service use in medical cannabis patients with chronic pain: a prospective study.

BMJ supportive & palliative care, 13(e2), e464-e468

Citation

Sznitman, Sharon; Mabouk, Carolyn; Said, Zahi; Vulfsons, Simon. (2023). Opioid and healthcare service use in medical cannabis patients with chronic pain: a prospective study.. BMJ supportive & palliative care, 13(e2), e464-e468. https://doi.org/10.1136/bmjspcare-2020-002661

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