Medical marijuana does not reduce opioid deaths
June 10, 2019
Science Daily/Stanford Medicine
Legalizing medical marijuana does not reduce the rate of fatal opioid overdoses, according to researchers at the Stanford University School of Medicine.
The finding contradicts a 2014 study that legal-pot advocates, public officials and even physicians have touted as a reason to legalize marijuana. That study found lower rates of fatal opioid overdoses in the states that had legalized marijuana for medical purposes than in states where marijuana remained illegal.
The Stanford study, which revisited the issue after many more states had legalized medical marijuana, found no evidence of a connection between opioid deaths and the availability of medical cannabis, said Keith Humphreys, PhD, professor of psychiatry and behavioral sciences.
"If you think opening a bunch of dispensaries is going to reduce opioid deaths, you'll be disappointed," Humphreys said. "We don't think cannabis is killing people, but we don't think it's saving people."
A paper describing the new study will be published online June 10 in Proceedings of the National Academy of Sciences. Humphreys is the senior author. The lead author is postdoctoral scholar Chelsea Shover, PhD.
Medical pot now legal in 47 states
In 1996, California became the first state to legalize medical marijuana. By 2010, 13 states, most of them in the West, had legalized medical marijuana. Today, 47 states permit some version of medical pot.
For the new study, the Stanford researchers used the same method employed in the 2014 study to evaluate the connection between legalized medical marijuana and fatal opioid overdoses. They confirmed the findings from the 2014 study, but when they looked at opioid deaths up to 2017 -- by which point most states had legalized some form of medical marijuana, if not recreational marijuana -- they found that the opposite was true: States with legal medical marijuana had a higher rate of deaths due to opioid overdose.
After the 2014 study was released, medical marijuana proponents and some public officials interpreted the results to mean that, given access to legalized pot, people would turn to it rather than opioids for pain relief or recreation. Yet when the Stanford researchers compared states that have more restrictive medical marijuana laws with those that allow recreational marijuana, they found no correlation between opioid overdose mortality and the level of restriction.
"Accounting for different types of laws didn't change the bottom line," Shover said.
Also, given that only 2.5% of the U.S. population uses medical marijuana, it's unlikely that use could affect mortality statistics, the researchers said.
'Something else about those states'
Humphreys said the results of the 2014 study may have reflected policies and conditions in states that legalized medical marijuana early. Those states tended to be wealthier and more politically liberal, with greater access to addiction treatment and to naloxone, which reverses the effects of opioids and can prevent overdose fatalities. The states that legalized pot early also incarcerate fewer people for drug use, Humphreys added. When people are released from prison, where they lack access to drugs and lose tolerance to them, they may try to use the same levels as they did before they were incarcerated, leading to overdose.
The finding of lower death rates "wasn't about the cannabis," Humphreys said. "It was something else about those states."
Humphreys and Shover said they believe that medical marijuana provides benefits and that research into its effectiveness should continue.
"There are valid reasons to pursue medical cannabis policies, but this doesn't seem to be one of them," Shover said. "I urge researchers and policymakers to focus on other ways to reduce mortality due to opioid overdoses."
https://www.sciencedaily.com/releases/2019/06/190610151933.htm
People who use medical marijuana more likely to use and misuse other prescription drugs
New study raises questions about cannabis to reduce opioid use
April 17, 2018
Science Daily/Wolters Kluwer Health
Can medical marijuana help to fight the opioid epidemic? Many believe that it can. But a new study finds that people who use medical marijuana actually have higher rates of medical and non-medical prescription drug use -- including pain relievers. The study appears in the Journal of Addiction Medicine, the official journal of the American Society of Addiction Medicine (ASAM), published by Wolters Kluwer.
Rather than being at lower risk, people who use medical marijuana may be at higher risk for non-medical prescription drug use, suggests the study by Theodore L. Caputi, BS of University College Cork's School of Public Health and Keith Humphreys, PhD, of Stanford University. However, an accompanying commentary questions whether medical cannabis is the cause of higher prescription drug use, or whether other factors explain the association.
Does Use of Medical Marijuana Increase or Decrease Prescription Drug Use?
The researchers analyzed more than 57,000 responses to the 2015 National Survey on Drug Use and Health. Participants were asked about medical and non-medical ("inconsistent with doctor's instructions") use of prescription drugs. The survey also asked about marijuana use, including whether it was recommended by a healthcare professional. The survey identified 776 people who used medical marijuana -- about 1.4 percent of all responders.
People who used medical marijuana were more likely to say they had used prescription drugs in the past year. They were about 60 percent more likely to report any prescription drug use, relative to those who did not use medical marijuana.
People who used medical marijuana were also more than twice as likely to report non-medical use of prescription drugs, including pain relievers, stimulants, and tranquilizers. "Non-medical use of pain relievers is of particular interest because of pain relievers' role in the opioid overdose epidemic," Mr. Caputi and Dr. Humphreys observe.
Higher levels of non-medical prescription drug use by people who used medical marijuana persisted in an analysis limited to people who used prescription drugs. The researchers write, "This suggests that the elevated risk for prescription drug non-medical use among people who use medical marijuana cannot be ascribed simply to their having a medical concern or greater access to prescription drugs."
Previous studies have reported that states where medical marijuana is legal have lower rates of medical and non-medical prescription drug use and related harms -- including opioid overdose. "These reports have led many to believe that use of medical marijuana is a protective factor against non-medical prescription drug use," Mr. Caputi comments. "However, individual-level inferences cannot be made using the ecological studies cited frequently in the debate over medical marijuana."
Mr. Caputi notes the lack of large-scale follow-up data on whether patients are using cannabis together with or in place of prescription drugs. However, he adds, "Physicians and practitioners should know that, from cross-sectional data, medical marijuana use is positively associated with non-medical prescription drug use.
"Our findings don't prove a causal connection between marijuana and opioid use, but they do suggest physicians can use medical marijuana as a marker for high risk of non-medical prescription drug use."
In the accompanying commentary, Marcus A. Bachhuber, MD, MSPH, and colleagues at Montefiore Medical Center/Albert Einstein College of Medicine point out that the findings do not show that medical cannabis causes increased use of prescription drugs. Dr. Bachhuber is author of an ecological study finding a protective effect of medical marijuana regulation on opioid overdose mortality,
"Given that people who take medical cannabis and those who do not are likely to have different underlying medical conditions, it is possible that medical cannabis use reduces prescription drug use yet prescription drug use remains relatively high in that group," Dr. Bachhuber comments, He notes that chronic pain is the most common reason for medical marijuana use.
In other studies, people who take medical marijuana consistently report substituting cannabis for other prescription and illicit drugs. Dr. Bachhuber and coauthors conclude: "To fully understand the effect of medical cannabis on the use of other drugs, prospective longitudinal studies randomizing patients to cannabis versus other treatments are urgently needed."
https://www.sciencedaily.com/releases/2018/04/180417181122.htm
Study questions link between medical marijuana and fewer opioid deaths
Association appears to be changing as medical marijuana laws and opioid epidemic change
February 7, 2018
Science Daily/RAND Corporation
The association between medical marijuana and lower levels of opioid overdose deaths -- identified previously in several studies -- is more complex than previously described and appears to be changing as both medical marijuana laws and the opioid crisis evolve, according to a new RAND Corporation study.
The report -- the most-detailed examination of medical marijuana and opioid deaths conducted to date -- found that legalizing medical marijuana was associated with lower levels of opioid deaths only in states that had provisions for dispensaries that made medical marijuana easily available to patients. Opioid death rates were not lower in states that just provided legal protections to patients and caregivers, allowing them to grow their own marijuana.
In addition, the association between medical marijuana dispensaries and fewer opioid deaths appears to have declined sharply after 2010, when states began to tighten requirements on sales by dispensaries.
"Our findings are consistent with previous studies showing an association between the legalization of medical marijuana and lower deaths from overdoses of opioids," said Rosalie Liccardo Pacula, co-author of the study and co-director of the RAND Drug Policy Research Center.
"However, our findings show that the mechanism for this was loosely regulated medical marijuana dispensaries, and that the association between these laws and opioid mortality has declined over time as state laws have more tightly regulated medical dispensaries and the opioid crisis shifted from prescription opioids to heroin and fentanyl," Pacula said. "This is a sign that medical marijuana, by itself, will not be the solution to the nation's opioid crisis today."
The study was published online by the Journal of Health Economics.
Researchers from RAND and the University of California, Irvine analyzed information about treatment admissions for addiction to pain medications from 1999 to 2012 and state-level overdose deaths from opioids from 1999 to 2013. They also identified state laws legalizing medical marijuana, examining provisions such as whether the regulations made marijuana easily accessible to patients by allowing dispensaries.
When the researchers narrowly focused on the time period from 1999 to 2010 and replicated a model used by other researchers, they obtained results similar to those previously published, showing an approximately 20 percent decline in opioid overdose deaths associated with the passage of any state medical marijuana law. However, these general findings were driven by states that had laws allowing for loosely regulated marijuana dispensary systems.
When researchers extended their analysis through 2013, they found that the association between having any medical marijuana law and lower rates of opioid deaths completely disappeared. Moreover, the association between states with medical marijuana dispensaries and opioid mortality fell substantially as well.
The researchers provide two explanations for the decline in the association between medical marijuana dispensaries and opioid harm. First, states that more recently adopted laws with medical marijuana dispensaries more tightly regulated them, in response to a U.S. Justice Department memo saying it would not challenge state-level medical marijuana laws so long as dispensary sales were in full compliance with state regulations. Second, beginning in 2010, the primary driver of the opioid crisis and related deaths became illicit opioids, mainly heroin and then fentanyl, not prescription opioids.
The study also found no evidence that states with medical marijuana laws experience reductions in the volume of legally distributed opioid analgesics used to treat pain. Even if medical marijuana patients were substituting medical marijuana for opioids in medical marijuana states, these patients did not represent a measurable part of the medical opioid analgesic market.
"While our study finds that medical marijuana dispensaries reduce some of the harms associated with the misuse of opioids, there is little evidence that this is happening because a large number of patients suffering from pain are using marijuana instead of opioid medications," Pacula said. "Either the patients are continuing to use their opioid pain medications in addition to marijuana, or this patient group represents a small share of the overall medical opioid using population."
The RAND study was conducted before any any states had begun to allow retail sales of recreational marijuana.
"Our research suggests that the overall story between medical marijuana and opioid deaths is complicated," Pacula said. "Before we embrace marijuana as a strategy to combat the opioid epidemic, we need to fully understand the mechanism through which these laws may be helping and see if that mechanism still matters in today's changing opioid crisis."
Support for the study was provided by the National Institute on Drug Abuse. Other authors of the study are David Powell of RAND and Mireille Jacobson of UC Irvine.
https://www.sciencedaily.com/releases/2018/02/180207090111.htm#