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Original Investigation
Health Care Policy and Law
May 2018

Association Between US State Medical Cannabis Laws and Opioid Prescribing in the Medicare Part D Population

Author Affiliations
  • 1Department of Public Administration & Policy, University of Georgia, Athens
  • 2Department of Health Policy & Management, University of Georgia, Athens
JAMA Intern Med. 2018;178(5):667-672. doi:10.1001/jamainternmed.2018.0266
Key Points

Question  What is the association between US state implementation of medical cannabis laws and opioid prescribing under Medicare Part D?

Findings  This longitudinal analysis of Medicare Part D found that prescriptions filled for all opioids decreased by 2.11 million daily doses per year from an average of 23.08 million daily doses per year when a state instituted any medical cannabis law. Prescriptions for all opioids decreased by 3.742 million daily doses per year when medical cannabis dispensaries opened.

Meaning  Medical cannabis policies may be one mechanism that can encourage lower prescription opioid use and serve as a harm abatement tool in the opioid crisis.

Abstract

Importance  Opioid-related mortality increased by 15.6% from 2014 to 2015 and increased almost 320% between 2000 and 2015. Recent research finds that the use of all pain medications (opioid and nonopioid collectively) decreases in Medicare Part D and Medicaid populations when states approve medical cannabis laws (MCLs). The association between MCLs and opioid prescriptions is not well understood.

Objective  To examine the association between prescribing patterns for opioids in Medicare Part D and the implementation of state MCLs.

Design, Setting, and Participants  Longitudinal analysis of the daily doses of opioids filled in Medicare Part D for all opioids as a group and for categories of opioids by state and state-level MCLs from 2010 through 2015. Separate models were estimated first for whether the state had implemented any MCL and second for whether a state had implemented either a dispensary-based or a home cultivation only–based MCL.

Main Outcomes and Measures  The primary outcome measure was the total number of daily opioid doses prescribed (in millions) in each US state for all opioids. The secondary analysis examined the association between MCLs separately by opioid class.

Results  From 2010 to 2015 there were 23.08 million daily doses of any opioid dispensed per year in the average state under Medicare Part D. Multiple regression analysis results found that patients filled fewer daily doses of any opioid in states with an MCL. The associations between MCLs and any opioid prescribing were statistically significant when we took the type of MCL into account: states with active dispensaries saw 3.742 million fewer daily doses filled (95% CI, −6.289 to −1.194); states with home cultivation only MCLs saw 1.792 million fewer filled daily doses (95% CI, −3.532 to −0.052). Results varied by type of opioid, with statistically significant estimated negative associations observed for hydrocodone and morphine. Hydrocodone use decreased by 2.320 million daily doses (or 17.4%) filled with dispensary-based MCLs (95% CI, −3.782 to −0.859; P = .002) and decreased by 1.256 million daily doses (or 9.4%) filled with home-cultivation–only-based MCLs (95% CI, −2.319 to −0.193; P = .02). Morphine use decreased by 0.361 million daily doses (or 20.7%) filled with dispensary-based MCLs (95% CI, −0.718 to −0.005; P = .047).

Conclusions and Relevance  Medical cannabis laws are associated with significant reductions in opioid prescribing in the Medicare Part D population. This finding was particularly strong in states that permit dispensaries, and for reductions in hydrocodone and morphine prescriptions.

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    3 Comments for this article
    EXPAND ALL
    Cannabis and pain
    DAVID KELLER, MD, MS | Retired internist
    The authors cite 7 papers as providing "clinical evidence that cannabis can be used to manage pain," references 17-23. The PubMed abstracts for these papers reveal that only three were clinical studies of the efficacy of cannabis as an analgesic; one was a safety study that did not report on efficacy, and 3 were review papers that generally pointed out the dearth of good studies of cannabis as an analgesic.


    The 3 clinical studies tested smoked cannabis versus placebo, but not against an opioid, NSAID, or other analgesic known to be effective against moderate to
    severe somatic pain. No assessment of blinding efficacy was reported, a crucial deficiency when testing a drug with obvious psychoactive effects that could easily lead to unmasking of the active drug and expectation effects rivaling the modest reported analgesic efficacies of cannabis. Finally, the pain indications tested in the 3 clinical trials were all rare neuropathic syndromes, a type of pain which is known to respond poorly to opioids and thus be an unlikely source for reduction of opioid prescribing.

    The proven benefits of cannabis do not yet, and might never, live up to the high hopes of its advocates, who would do well to remember that cannabinoids, like caffeine, nicotine and other plant neurotoxins, evolved to make the plant less likely to be eaten, by injuring or impairing the CNS of animals that consume too much of the plant.
    CONFLICT OF INTEREST: None Reported
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    Adding a Personal Experience
    Kristina Etter | Patient
    I am not a doctor. I am, however, college educated and spent a couple of decades in the business world. In other words, I can read and I'm definitely no idiot. I'd like to add a personal experience for anyone doubting the statistics in this report.

    My husband is one of those statistics - an opioid survivor. He spent 10 years being told by physicians in the Midwest that opioids would just be a part of his life. A failed cervical neck fusion, degenerative disk disease, and spinal stenosis were turning my 40-year-old husband into an invalid, and
    the pills the doctors prescribed were only making matters worse. Every month we would beg his doctors for alternatives to the drugs, but every month we were told it was just part of the treatment plan. At one point in time they had him taking four hydrocodone, 4 percoset, and 2 fentenyl patches a day. He was NOT the man I married.

    When his prescriptions would lapse, withdrawal would set in within hours. If the physical aspects didn't start on their own, the mental aspects of anticipating the sickness would. I would watch as tremors, insomnia, agitation, nausea, and vomiting would overcome him. I would have to call and beg for bridge prescriptions just to keep him functional until his next doctor appointment.

    In  2016, after uprooting our lives to move to a different state - my husband stopped taking his prescriptions. Completely. Walked away. He didn't experience one single day of withdrawal. Not one. He started taking high dose CBD's to control withdrawal and THC edibles to control the pain. Today, two and half years later, my husband is walking, talking, living proof it CAN work. The sooner we stop pretending it can't... the more lives will be saved.


    Stop doubting and start advocating for better research.
    CONFLICT OF INTEREST: None Reported
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    Reply to "Patient's Personal Experience", revised
    DAVID KELLER, MS, MD | David Louis Keller, MS, MD, FACP
    A cannabis advocate has submitted a touching anecdote regarding cannabis, along with an urgent plea for doctors to make greater medical use of cannabis derivatives for analgesia.

    I wish cannabis were completely legal to grow, sell and use in private, with safety restrictions similar to those on tobacco and alcohol. Total federal and state cannabis legalization would yield important benefits, including fewer testimonials submitted by cannabis advocates to medical journals, and fewer demands that physicians prescribe more cannabis.

    Until it is legalized, however cannabis patient anecdotes and testimonials should be scrutinized.

    It's hard to believe that the
    patient's physicians insisted on "him taking four hydrocodone pills, 4 percocet, plus 2 fentanyl patches a day". This mixture of oral oxycodone and hydrocodone (including up to 4 grams of acetaminophen per day) sounds, at best, like a misunderstanding. And why would "his doctors" turn down the patient's request for alternatives to opioids? Were they seeking to endanger their medical licenses, and their freedom, by prescribing opioids the patient did not want?

    We learn that his opioid prescriptions were "lapsing", and the patient had to "call and beg" for a "bridge prescription", which seems to indicate that someone was forgetting to follow up monthly. Physicians who insist on prescribing a  mix of opioids, but refuse to provide a sufficient supply to last until the patient's next visit, are frequent culprits in these tales.

    Unfortunately, cannabis remains Schedule I, illegal to prescribe in the United States, even in states which have legalized it. And the FDA has not approved cannabis derivatives, except for rare, narrow indications, such as intractable infantile seizures and AIDS wasting.

    Cannabis apparently helped this patient get off opioids, but we cannot really draw any conclusions from this case, or any number of similar testimonials and anecdotes.  

    CONFLICT OF INTEREST: None Reported
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