Medical Marijuana and Opioids (MEMO) Study: Protocol of a Longitudinal Cohort Study to Examine If Medical Cannabis Reduces Opioid Use Among Adults with Chronic Pain
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Open access Protocol BMJ Open: first published as 10.1136/bmjopen-2020-043400 on 29 December 2020. Downloaded from Medical Marijuana and Opioids (MEMO) Study: protocol of a longitudinal cohort study to examine if medical cannabis reduces opioid use among adults with chronic pain Chinazo O Cunningham ,1 Joanna L Starrels,1 Chenshu Zhang,1 Marcus A Bachhuber,2 Nancy L Sohler,3 Frances R Levin,4 Haruka Minami,5 Deepika E Slawek,1 Julia H Arnsten1 To cite: Cunningham CO, ABSTRACT Strengths and limitations of this study Starrels JL, Zhang C, et al. Introduction In the USA, opioid analgesic use and Medical Marijuana and overdoses have increased dramatically. One rapidly ► This study examines how long- term medical can- Opioids (MEMO) Study: expanding strategy to manage chronic pain in the protocol of a longitudinal nabis use affects opioid analgesic use, including context of this epidemic is medical cannabis. Cannabis cohort study to examine if products with different Δ9- tetrahydrocannabinol has analgesic effects, but it also has potential adverse medical cannabis reduces and cannabidiol content. effects. Further, its impact on opioid analgesic use is not opioid use among adults ► The study also examines how long- term medical well studied. Managing pain in people living with HIV with chronic pain. BMJ Open cannabis use affects HIV outcomes and adverse is particularly challenging, given the high prevalence 2020;10:e043400. doi:10.1136/ events. bmjopen-2020-043400 of opioid analgesic and cannabis use. This study’s ► Measurement of cannabis and opioid use will be overarching goal is to understand how medical cannabis ► Prepublication history for precise given 39 self-reported measures every use affects opioid analgesic use, with attention to 9- this paper is available online. Δ 2 weeks, along with dispensing data from New tetrahydrocannabinol and cannabidiol content, HIV To view these files, please visit York’s Prescription Monitoring Program. the journal online (http:// dx. doi. outcomes and adverse events. ► Because medical cannabis products dispensed to org/ 10. 1136/ bmjopen- 2020- Methods and analyses We are conducting a cohort participants have undergone independent laborato- http://bmjopen.bmj.com/ 043400). study of 250 adults with and without HIV infection with ry evaluation, the exact content of these products is (a) severe or chronic pain, (b) current opioid use and (c) known and accurate. Received 03 August 2020 who are newly certified for medical cannabis in New York. ► Because the study design is a longitudinal cohort Revised 29 November 2020 Over 18 months, we collect data via in- person visits every Accepted 30 November 2020 study, analyses examine changes over time within 3 months and web- based questionnaires every 2 weeks. participants, and biases that could affect outcomes Data sources include: questionnaires; medical, pharmacy may be unmeasured. and Prescription Monitoring Program records; urine and blood samples; and physical function tests. Using marginal structural models and comparisons within participants’ on September 26, 2021 by guest. Protected copyright. 2- week time periods (unit of analysis), we will examine with HIV.1–17 To address pain, over the past how medical cannabis use (primary exposure) affects (1) decades, opioid analgesic use has dramat- opioid analgesic use (primary outcome), (2) HIV outcomes ically increased.18 19 Subsequently, opioid (HIV viral load, CD4 count, antiretroviral adherence, HIV risk use disorder and overdose have increased behaviours) and (3) adverse events (cannabis use disorder, 18 20 21 illicit drug use, diversion, overdose/deaths, accidents/ to unprecedented levels. Among injuries, acute care utilisation). people living with HIV, this trend is magni- © Author(s) (or their Ethics and dissemination This study is approved by the fied; as people living with HIV have dispro- employer(s)) 2020. Re- use Montefiore Medical Center/Albert Einstein College of Medicine portionately high chronic pain and opioid permitted under CC BY-NC. No institutional review board. Findings will be disseminated analgesic use, despite their elevated risk commercial re- use. See rights through conferences, peer- reviewed publications and 6 14 22–26 and permissions. Published by of opioid misuse and use disorder. BMJ. meetings with medical cannabis stakeholders. With concerns about opioid analgesic use Trial registration number ClinicalTrials. gov Registry For numbered affiliations see and guidelines recommending non- opioid end of article. (NCT03268551); Pre- results. therapies, medical cannabis has emerged as an important treatment option.27 As of Correspondence to Dr Chinazo O Cunningham; INTRODUCTION November 2020, 35 states and Washington, chinazo. cunningham@ Chronic pain is common among American DC have legalised medical cannabis, with einsteinmed. org adults and particularly among people living pain as the most common indication.28 Cunningham CO, et al. BMJ Open 2020;10:e043400. doi:10.1136/bmjopen-2020-043400 1 Open access BMJ Open: first published as 10.1136/bmjopen-2020-043400 on 29 December 2020. Downloaded from Cannabis contains more than 60 active cannabinoids; (cancer, HIV infection or AIDS, amyotrophic lateral the two most active in cannabinoid receptor activation are sclerosis, Parkinson’s disease, multiple sclerosis, spinal Δ9- tetrahydrocannabinol (THC) and cannabidiol (CBD).29 cord injury with spasticity, epilepsy, inflammatory bowel The main psychotropic cannabinoid in cannabis, THC, can disease, neuropathy, Huntington’s disease, post-traumatic produce euphoria or anxiety, along with having an effect stress disorder, chronic pain, pain that degrades health on pain and other symptoms.29 CBD is non- psychoactive and functional capability as an alternative to opioid use, and also has analgesic, anti-inflammator y, antioxidant, anti- or substance use disorder) and at least one complication convulsant and anxiolytic effects.29 A combination of THC (severe or chronic pain resulting in substantial limita- and CBD may be more effective in treating pain than THC tion of function, cachexia or wasting syndrome, severe alone, as CBD appears to both potentiate and block partic- nausea, seizures, severe or persistent muscle spasms, ular pharmacological effects of THC.30–34 post- traumatic stress disorder or opioid use disorder). Numerous short- term randomised controlled trials Medical cannabis products must be purchased from a have demonstrated that compared with placebo, cannabis state- licensed dispensary which have pharmacists on-site, use reduces pain.35–49 In 2017, a landmark review found companies must offer products with a variety of THC and ‘conclusive or substantial evidence’ that cannabis is effec- CBD content, and all products are tested by an indepen- tive in treating chronic pain.50 While existing randomised dent lab to confirm content. Dispensaries upload records controlled trials provide evidence about the effect of cannabis of all medical cannabis products dispensed to the NY on pain, they were short term, and only one included prod- Prescription Monitoring Program (PMP). Despite states’ ucts with different THC/CBD content.45 Importantly, they widespread legalised medical cannabis policies, at the did not examine the relationship between cannabis and federal level, cannabis remains classified as a Schedule 1 opioid analgesic use. substance with ‘no currently accepted medical use and Limited evidence from cross-sectional and ecological a high potential for abuse’.94 Because of this classifica- studies suggests that cannabis use is associated with reduced tion, federally funded cannabis research is extremely opioid analgesic use. In several cross-sectional surveys, restricted.50 95 From a clinical perspective, physicians patients taking medical cannabis reported taking less opioid cannot prescribe medical cannabis like other medica- analgesics after using medical cannabis or substituting it for tions; they can only certify patients to purchase it. In NY, opioid analgesics.51–56 In population- level studies through unless providers recommend a specific dose or type of 2013, medical cannabis availability was associated with lower product, patients can choose THC/CBD content, dose, rates of opioid analgesic prescription and lower rates of amount and route of administration. fatal opioid overdoses.57 58 To fully understand the potential Because chronic pain is common and difficult to implications of medical cannabis legalisation on the opioid manage, non- opioid pain management strategies are epidemic, longitudinal studies that focus on patient- level recommended, and legalised medical cannabis use opioid analgesic use are necessary. continues to grow, the goal of our longitudinal cohort http://bmjopen.bmj.com/ Cannabis use is common in people living with HIV and study is to improve understanding of how medical can impact HIV outcomes through a variety of mecha- cannabis use affects opioid analgesic use over time, nisms.59–68 Studies examining the relationship between with particular attention to THC/CBD content, HIV cannabis use and HIV outcomes have had conflicting outcomes and adverse events. We hypothesise that: (1) results in terms of HIV viral load, CD4 count and antiret- medical cannabis use will be associated with a reduc- roviral adherence.59 63 69–78 However, one consistent finding tion in opioid analgesic use; (2) the association between is cannabis’s association with high- risk behaviours for HIV medical cannabis and opioid analgesic use will differ by 62 79–83 transmission.