Researchers who looked at opioid prescription and mortality rates in Oregon found that nearby access to retail marijuana moderately reduced opioid prescriptions, though they observed no corresponding drop in opioid-related deaths.
Specifically, communities located within a mile of state-licensed cannabis outlets had prescription opioid rates that were 1.0 percent to 3.9 percent lower than surrounding areas, according to the analysis, published this week in the journal Regional Science and Urban Economics.
Prescription rates were higher among communities located between 1 mile and 4 miles to a dispensary. They were higher still as distances to retail marijuana grew to between 4 miles and 10 miles, and even greater between 10 miles and 20 miles.
The findings further the idea of a substitution effect wherein patients opt for cannabis instead of opioids to treat pain.
“There is evidence that this effect is nonlinear and diminishes as the distance from a dispensary rises,” the study says. Results suggested that “a 1 percent increase in the distance traveled is associated with a statistically significant 0.014 percent increase” in per capita opioid prescription rates, as measured in morphine milligram equivalents.
“Recreational cannabis reduces prescription opioids per capita by 1.0–3.9 percent.”
Past research into the substitution effect has suggested that medical marijuana legalization can significantly reduce both opioid prescriptions and mortality. The new findings indicate that recreational marijuana laws may have a “significantly smaller” impact on prescribing.
And unlike some past studies on medical marijuana, the new research observed no drop in opioid death rates associated with adult-use cannabis.
The study was authored by Western Michigan University economics professor W. Jason Beasley and Steven Dundas, an economics professor at Oregon State University.
“We cannot know for sure why we see a reduction in prescription opioid use and not a mortality effect given our data constraints,” the pair told Marijuana Moment in an email about the report, “but a potential explanation could be that either the substitution effect is not large enough, or possibly, those who are most likely to succumb to opioid misuse are not making this particular substitution.”
“Our findings support existing literature that suggests a substitution arises between legal cannabis and prescription opioids,” they added, but also “offer a note of caution about the idea that recreational cannabis laws are a panacea to solve the opioid epidemic.”
“Communities located closer to recreational dispensaries are associated with lower rates of prescription opioids per capita.”
While existing research has generally compared states with legal marijuana to states where the drug remains prohibited, the new study looks specifically at communities within Oregon, drawing from data on prescription opioid quantities, access to marijuana and opioid mortality from January 2014 to December 2017, a period that it notes “captures nearly two years of data pre- and post-RCL in Oregon.” Opioid prescription data came from the Oregon Health Authority’s Public Health Division.
“The idea that has permeated much of the research landscape is that cannabis can reduce opioid mortality through either substituting away from opioids or moderating opioid usage,” authors told Marijuana Moment. “Our research in Oregon was an attempt to estimate the magnitude of substitution behavior between cannabis and prescription opioids and also test if a mortality effect associated with recreational cannabis was present with more localized data within a single US state.”
The study acknowledges that while opioid-related mortality rates appeared unaffected by proximity to retail marijuana, it’s possible that other measures of opioid harms, for example hospitalizations, may nevertheless show an impact.
“While mortality rates do not appear to be driven by changes in cannabis access,” it says, “hospitalizations related to overdoses may be impacted. An extension of this work assessing hospitalizations in lieu of mortality…may yield further insight.”
Authors said in the email to Marijuana Moment that the issue of hospitalizations “was raised during peer review of the article and our discussion in the paper on hospitalizations is meant to convey that mortality reduction is just one metric that could be impacted by reduced opioid prescriptions.”
“For example, it may be possible that the same number of people succumb to opioid misuse, while fewer people are hospitalized,” they added.
Asked about recent findings that many people use cannabis therapeutically without identifying as medical marijuana patients, Beasley and Dundas noted their study used aggregate prescription data, not individual survey responses, “so we simply cannot know what the exact reasons are for people to make this substitution.”
“However, this type of use is reflective of our initial hypothesis about why we might find a substitution away from prescription opioids when cannabis is more accessible,” they continued. “In other words, yes this is a very plausible explanation for our results, but we cannot know for sure that this type of behavior is driving the effect.”
The earlier study, in Journal of the American Medical Association (JAMA), found most cannabis consumers—76 percent—“reported using cannabis to manage a range of symptoms,” such as pain, stress and sleep issues. But only 16 percent said they were medical marijuana users, and just 31.1 percent said their use was for both nonmedical and medical purposes.
“Less than half the patients who used cannabis reported using it for medical reasons, even though the majority of patients reported cannabis use to manage a health-related symptom,” that report says. “This aligns with another study that found that this type of cannabis use is clinically underrecognized.”
Other recent research also indicates that cannabis may be an effective substitute for opioids in terms of pain management.
A report published recently in the journal BMJ Open, for instance, compared medical marijuana and opioids for chronic non-cancer pain and found that cannabis “may be similarly effective and result in fewer discontinuations than opioids,” potentially offering comparable relief with a lower likelihood of adverse effects.
A federally funded study published last month, meanwhile, concluded that even some cannabis terpenes may have pain-relieving effects. That research found that an injected dose of the compounds produced a “roughly equal” reduction in pain markers in mice when compared to a smaller dose of morphine. Terpenes also appeared to enhance the efficacy of morphine in mice when the two drugs were given in combination.
Another study, published late last year, found that marijuana and opioids were “equally efficacious” at mitigating pain intensity, but cannabis also provided more “holistic” relief, such as by improving sleep, focus and emotional wellbeing.
That same month, research published in the Journal of Dental Research found that pure CBD could alleviate acute dental pain about as well as an opioid formula commonly used in dentistry.
The impact of cannabis reform on opioid use and prescription rates has been a topic of inquiry and debate since the earliest state cannabis laws. While findings have been mixed, generally research has indicated that expanding access to cannabis has led to declines in opioid use.
A study published last summer linked medical marijuana use to lower pain levels and reduced dependence on opioids and other prescription medications. Another, published by the American Medical Association (AMA) in February, found that chronic pain patients who received medical marijuana for longer than a month saw significant reductions in prescribed opioids.
About one in three chronic pain patients reported using cannabis as a treatment option, according to another AMA-published report last year. Most of that group said they used cannabis as a substitute for other pain medications, including opioids.
Other research published last year found that letting people buy CBD legally significantly reduced opioid prescription rates, leading to 6.6 percent to 8.1 percent fewer opioid prescriptions.
A 2022 research paper that analyzed Medicaid data on prescription drugs, meanwhile, found that legalizing marijuana for adult use was associated with “significant reductions” in the use of prescription drugs for the treatment of multiple conditions.
Researchers who looked at opioid prescription and mortality rates in Oregon found that nearby access to retail marijuana moderately reduced opioid prescriptions, though they observed no corresponding drop in opioid-related deaths. Specifically, communities located within a mile of state-licensed cannabis outlets had prescription opioid rates that were 1.0 percent to 3.9 percent lower than surrounding Read More
