Legalized Cannabis Is Reducing Opioid Use In Cancer Patients, Say Researchers At Weill Cornell Medicine

The legalization of medical marijuana is reducing opioid use in cancer patients.

In a paper published in the journal JAMA Oncology on December 1, medical marijuana was associated with a 5.5% to 19.2% relative reduction in the rate of opioid dispensing to 38,189 adult patients newly diagnosed with breast, colorectal or lung cancer and receiving cancer treatment. These three cancer types were chosen for the study because of the large number of new cases among those younger than 65.

“Medical marijuana could be serving as a substitute for opioid therapies among some adult patients receiving cancer treatment; future studies need to elucidate the nature of the associations and implications for patient outcomes,” noted the study.

Opioids, which are highly addictive, are used to treat all types of pain, including cancer-related pain; they have also been linked to increased self-administration and deadly overdoses.

More than 93,000 people died of a drug overdose in the U.S. in 2020 - a record number that reflects a rise of nearly 30% from 2019, according to the Centers for Disease Control and Prevention. Officials noted the increase was driven by opioids and the lethal prevalence of fentanyl.  

"The magnitude of the reduction [of opioid dispensing in cancer patients] varied by the type of cancer and whether the patient received prescription opioids prior to their cancer diagnosis,” Yuhua Bao, lead author of the paper and a health economist at Weill Cornell Medicine told Newsweek.

"Our findings suggest that with increasing medical marijuana legalization, marijuana may be substituting for opioids for cancer-related pain to some extent.”

Decrease In Demand For Opioids?

The reason for the reduction in opioid dispensing is not known though Bao says a combination of factors may have contributed, including reduced patient requests for opioids and therefore reduced clinicians prescribing them.

"These behaviors could be driven by actual substitution of medical marijuana for opioids or perceived substitutability," she added.

Legal access to medical marijuana may have led oncologists and other practitioners to prescribe fewer opioids, or perhaps they are not as frequently being asked for them by patients who are self-managing their pain with cannabis.

"Without data on clinician practices or patient use of medical marijuana, the nature of the observed associations remains uncertain," the authors wrote in the paper.

"The findings suggest that medical marijuana could be serving as a substitute for opioids to some extent. Future studies need to elucidate the nature of the associations and their implications for patient outcomes."

Photo by National Cancer Institute on Unsplash