Longer Use of Medical Cannabis May Decrease Opioid Dosage Among Long-Term Users

Longer duration of medical cannabis treatment was associated with reductions in opioid dosage among patients with chronic pain on long-term opioid therapy (LTOT), according to the results of a cohort study published in JAMA Network Open.

Investigators from the New York State Department of Health sourced data for this study from the Medical Marijuana Data Management System (MMDMS) and the New York State Prescription Monitoring Program registry (PMP). Between 2017 and 2019, 8165 patients with chronic pain who were dispensed at least 1 prescription for medical cannabis and who were receiving LTOT were evaluated for opioid dosage in the first 8 months of medical cannabis use. Long-term opioid use was defined as 120 or greater cumulative days of opioid prescription or 10 or more prescriptions within the previous 12 months.

Patients received medical cannabis for at least 30 (n=4124) or fewer than 30 (n=4041) days. The median ages of patients receiving shorter-term and longer-term medical cannabis were 54 (interquartile range [IQR], 44-62) and 57 (IQR, 47-65) years, 57.5% and 58.8% were women, 61.1% and 63.1% had private insurance (P <.001), and the median morphine milligram equivalent (MME) opioid dose at baseline was 55.3 (IQR, 30.0-98.5) and 50.0 (IQR, 30.0-97.5) mg, respectively.

In general, in the year before medical cannabis use, opioid dosage remained relatively stable.

Stratified by baseline MME, individuals with an MME <50 mg at baseline experienced a dosage change of -14.53 mg, those with an MME of 50 mg to <90 mg experienced a dosage change of -29.49 mg, and those with an MME of ≥90 mg experienced a dosage change of -69.81 mg over the 8-month intervention period among the individuals with longer medical cannabis duration compared with those with shorter medical cannabis duration.

Although the raw decrease in opioid dosage was positively related to baseline MME dose, the relative proportion in opioid dosage decrease was similar over time among the <50-mg (48% vs 4%), 50 mg to <90-mg (47% vs 9%), and ≥90-mg (51% vs 14%) MME groups among those receiving longer- vs shorter-duration medical cannabis, respectively.

A major limitation of this study was that dose or method of medical cannabis ingestion was not evaluated.

Study authors conclude, “This cohort study found that receiving [medical cannabis] for longer was associated with opioid dosage reductions. The reductions were larger among individuals who were prescribed higher dosages of opioids at baseline. These findings contribute robust evidence for clinicians regarding the potential benefits of [medical cannabis] in reducing the opioid burden for patients receiving LTOT and possibly reduce their risk for overdose.”