When Chronic Pain Patients Join New Yorks Medical Cannabis Program Does Their Prescription Opioid Use Actually Go Down?

Study basics: Who, where and when?

The JAMA Internal Medicine paper, titled “Medical Cannabis and Opioid Receipt Among Adults With Chronic Pain,” was led by Dr. Deepika Slawek and colleagues at Montefiore Medical Center and Albert Einstein College of Medicine in the Bronx, New York. READ ABOUT: JAMA Network

Design and timeframe

  • Type of study: Prospective cohort study
  • Data source: New York State Prescription Monitoring Program (NYS PMP)
  • Study period for prescriptions: September 2018 – July 2023
  • Follow-up: 18 months of prospective monitoring after patients entered the medical cannabis program

Who was included?

  • 204 adults with chronic pain
  • All were already prescribed opioids for pain management
  • All were newly certified for medical cannabis in New York State’s program
  • Participants were recruited from a large academic medical center and nearby medical cannabis dispensaries in the Bronx.

At baseline:

  • Mean age: about 57 years
  • 55% were women
  • Average pain severity and pain interference scores were both around 6.6–6.8 out of 10, indicating substantial pain burden.

How did they measure cannabis and opioid use?

The study leveraged the highly regulated nature of New York’s program.

Medical cannabis exposure

Participation wasn’t just “yes/no.” Researchers looked at the “portion of days covered” each month by dispensed medical cannabis—as reported by pharmacists in the state’s registry. In other words, they could see:

  • Which months a participant actually picked up medical cannabis
  • Whether they had a 30-day supply on hand vs. no supply

The program itself is pharmacist-directed, meaning licensed pharmacists in dispensaries help patients choose products and dosages, which is a more medicalized model than in many other states. READ MORE: News-Medical

Opioid outcomes

The main outcome was prescription opioid receipt, measured as:

  • Mean daily morphine milligram equivalents (MME) per month, based on the NYS prescription monitoring program.

The researchers used marginal structural models to control for both:

  • Fixed factors (like baseline characteristics)
  • Time-varying factors (including pain scores and even self-reported use of unregulated/non-program cannabis).

They also tracked non-prescribed opioid use during follow-up to see whether patients were replacing prescriptions with illicit opioids (they did not find evidence of a shift to non-prescribed opioid use overall). READ MORE: EurekAlert!

What did the study find?

Overall drop in opioid doses

At the start of the study:

  • Baseline mean daily opioid dose was 73.3 MME.

After 18 months:

  • Mean daily dose dropped to 57.4 MME—about a 22% reduction over time.

The key question was whether more consistent medical cannabis use was linked to greater reductions.

Compared with months in which no medical cannabis was dispensed:

  • Months where participants received a full 30-day supply of medical cannabis were associated with 3.53 fewer MME per day on average (β = –3.53; 95% CI, –6.68 to –0.04; P = .03).

That might sound small, but the authors and outside commentators frame it as:

  • A gradual, sustainable reduction rather than abrupt tapering
  • Clinically consistent with the current emphasis on slow, careful dose reductions for long-term opioid therapy, which is considered safer than sudden discontinuation. READ MORE: PR Newswire

NORML’s summary of the data highlights that mean daily MME was roughly 22% lower by the end of follow-up, reinforcing the idea of a real, if modest, opioid-sparing effect among program participants. READ MORE: NORML

No evidence of “compensating” with street opioids

Importantly, the study did not find an increase in nonprescribed opioid use during the follow-up period. That helps counter a common concern that reducing prescriptions might simply push patients toward illicit opioids like heroin or fentanyl—at least within this cohort and timeframe.

How does this fit with earlier New York data?

This isn’t the first New York–based study to report an opioid-sparing signal from medical cannabis.

In 2023, a larger JAMA Network Open cohort study examined more than 8,000 chronic pain patients on long-term opioid therapy who received medical cannabis between 2017 and 2019. It found that:

  • Longer duration of medical cannabis use was associated with larger reductions in prescribed opioid dosages, and
  • Patients starting at higher opioid doses saw greater absolute reductions.

Taken together, the 2023 statewide study and the new 2018–2023 Bronx cohort add converging evidence that access to state-regulated medical cannabis may help some chronic pain patients gradually reduce their reliance on opioids.

What does this not show?

The authors are careful about what they don’t claim.

  • This is an observational study, not a randomized trial. It can show association, not proof of causation. Other factors (like broader changes in prescribing guidelines or individual patient motivation) could also contribute.
  • The sample size is relatively small (204 patients) and from one urban region (the Bronx). Results might not fully generalize to rural areas, other states, or less regulated cannabis markets.
  • The study doesn’t say that cannabis is a cure-all, or that every patient reduced opioids; it reports average trends across the cohort.

The authors also acknowledge there are open questions about:

  • Optimal cannabis products, doses, and THC/CBD ratios
  • Long-term safety of chronic medical cannabis use
  • How best to integrate cannabis into multimodal pain care rather than treat it as a stand-alone solution

Why the findings matter

Despite the limitations, this study is notable for several reasons:

  1. Prospective design & high-quality data
    • It followed patients forward in time with detailed pharmacy and PMP data rather than relying only on cross-sectional snapshots or self-report.
  2. Highly medicalized program
    • New York’s pharmacist-directed model may be closer to how many clinicians would like to see cannabis used: with documented dosing, product tracking, and clinical oversight rather than purely retail or informal use. READ MORE: News-Medical
  3. Alignment with broader evidence
    • The findings line up with the 2023 JAMA Network Open New York study, as well as other research suggesting medical cannabis access is associated with reduced opioid prescribing or dosing in some patient groups.
  4. Policy implications
    • For policymakers wrestling with the opioid crisis, the study strengthens the case that well-regulated medical cannabis programs could be one tool—not a silver bullet, but a potential harm-reduction strategy—especially for patients already on long-term opioid therapy.

Takeaway

Between 2018 and 2023, chronic pain patients in New York who entered the state’s medical cannabis program and were followed for 18 months saw gradual, statistically significant drops in prescribed opioid doses, with no evidence of switching to illicit opioids in this cohort.

The study doesn’t prove that cannabis alone caused those reductions—but it adds to a growing stack of evidence that, within a tightly regulated, pharmacist-supervised framework, medical cannabis may help some patients step down their opioid use more safely over time.