Medical Cannabis for Pain Management Save

Recent research and publications have underscored the use, efficacy, safety and limitations to the use of cannabis for arthritis and pain patients.

Chronic pain affects more than one in five American adults, yet practitioners are limited in treatment alternatives. Even if we exclude the use of narcotics and opioids, many of the drugs we have relied upon in the past have either shown to be unsafe or of little or no benefit – including acetaminophen, propoxyphene, tramadol, gabapentin, NSAIDs, etc.

Widespread, state regulated availability of medical cannabis isa potential option, with approximately 27% of US and Canadian adults reporting they have used cannabis for medical purposes.  In the USA, cannabis is legal in 40 of 50 states for medical use and 24 states for recreational use.

However, most clinicians report lacking confidence in their knowledge of cannabis therapeutics, largely owing to a lack of well-done clinical trials to demonstrate their safe use and efficacy.  This summary examines four recent studies exploring the efficacy and safety of medical cannabis for pain management, including its role in reducing opioid use, its impact on rheumatic conditions, and comprehensive clinical guidance for healthcare providers.

The research presents a complex picture of medical cannabis in pain management. A comprehensive JAMA review emphasizes that evidence remains insufficient for most medical indications beyond the few FDA-approved uses, and highlights significant risks including cardiovascular complications, psychiatric effects, and cannabis use disorder. A prospective study from New York State demonstrated that participation in a pharmacist-supervised medical cannabis program was associated with meaningful reductions in prescription opioid use among chronic pain patients over 18 months. Expert consensus from Argentina identified fibromyalgia and osteoarthritis as rheumatic conditions showing the most promise for cannabis treatment, though researchers emphasized the need for more rigorous trials. Meanwhile, a Canadian population study revealed concerning evidence that increased exposure to cannabis retail stores was linked to higher rates of cannabis-related emergency department visits, highlighting potential public health risks associated with easier access to cannabis products.

Medical Cannabis and Opioid Use Reduction (JAMA Internal Medicine)

A Montefiore Medical Center, 18-month prospective cohort study of 204 adults with chronic pain taking prescribed opioids (pain scores of ~6.8/10) examined the benefits of also taking medical cannabis. Nearly half had moderate to severe depression, and many had insomnia, anxiety, or PTSD. After 18 mos. of the state approved medical cannabis program average daily opioid doses had decreased by 22% (73.3 to 57.4 morphine milligram equivalents (MME) daily). Most participants used lower-risk cannabis products like edibles, rather than smoked forms.  Those who took medical took ~3.5 fewer MME per day   The findings support a medicalized approach to cannabis dispensation involving trained pharmacists and clinicians.

Cannabis for Rheumatic Pain (Medscape)   

The 58th Argentine Congress of Rheumatology reviewed evidence for medical cannabis in treating rheumatic conditions. Fibromyalgia and osteoarthritis had the strongest supporting evidence as second-line options. A systematic review examining 28 studies found reports of significant improvements in pain, sleep, and mood in fibromyalgia. Studies in rheumatoid arthritis showed pain reduction and decreased inflammatory markers in some cases. Research also suggested potential benefits for scleroderma symptoms like digital ulcers and pain. A 2020 meta-analysis found that one in five rheumatology patients actively use cannabis and experience significant pain relief. An Israeli clinic survey of 319 patients (82% with fibromyalgia) reported a 77% decrease in pain intensity and 78% improvement in sleep quality. While these reports suggest efficacy, safety was described as generally mild, with common side effects including drowsiness, dizziness, and dry mouth. The addiction potential of medical doses appears comparable to commonly prescribed benzodiazepines or opioids. The recommended approach involves starting with CBD-dominant formulations for chronic pain patients, adding small amounts of THC at night if needed for sleep and enhanced pain relief. These researchers noted significant limitations in the current evidence and the need for further research.

Cannabis Retail Store Exposure and Harms (Annals of Internal Medicine) 

Canadian researchers conducted an Ontario population-based natural experiment (2017 to 2022) where they tracked the opening of cannabis retail stores (Canada legalized in 2018) and subsequent cannabis-attributable emergency department visits. They found that before cannabis stores opened, cannabis-related ED visits were already increasing. After stores opened in exposed neighborhoods, these visits remained constant, while they decreased in unexposed neighborhoods. Thus, the exposed neighborhoods experienced an additional 1.30 cannabis-attributable ED visits per 100,000 persons monthly, representing a 12% relative increase compared to unexposed areas.  Hence, physical proximity to cannabis retail outlets is associated with increased cannabis-related harms at the population level. This study demonstrates that how cannabis legalization is implemented (local and density) may significantly influence public health outcomes.

Comprehensive Clinical Review of Cannabis Therapeutics (JAMA)

A comprehensive review published in JAMA by Hsu and colleagues synthesized evidence across 124 studies to provide clinical guidance on therapeutic cannabis use. The review showed FDA-approved cannabinoids have modest benefits but a few approved indications:

• HIV/AIDS-induced anorexia: dronabinol moderately increased body weight
• Chemotherapy-induced nausea and vomiting: dronabinol and nabilone are modestly better than placebo or active comparators
• Certain pediatric seizure disorders: oral cannabidiol reduced seizure frequency

But for most conditions where cannabis is used (chronic pain, insomnia, anxiety) evidence of efficacy is insufficient.

Risks associated with cannabis use were higher with high-potency products (10% or more THC) compared to low-potency cannabis. High potency was associated with increased rates of psychotic symptoms (12.4% versus 7.1%) and generalized anxiety disorder (19.1% versus 11.6%). Among individuals using cannabis for medical purposes, 29% met criteria for cannabis use disorder. Daily inhaled cannabis use, compared to non-daily use, was linked to increased risk of coronary heart disease (2.0% versus 0.9%), myocardial infarction (1.7% versus 1.3%), and stroke (2.6% versus 1.0%).

The authors advised clinical screening recommendations before initiating cannabis or cannabinoids. They advised against use in patients with:

• substance use disorders
• mental illness
• cardiovascular disease
• pregnancy or breastfeeding
• individuals under age 25 (due to neurodevelopmental concerns)

Other recommendations:

• Screen for cannabis use disorder and cannabis hyperemesis syndrome
• Watch drug-drug interactions,
• Watch for CBD's effects on liver enzymes (especially in patients taking warfarin and immunosuppressants)
• Use lower potency products, non-inhaled routes, lower doses
• Avoiding concurrent use with other central nervous system depressants
• Purchasing cannabis products only from regulated sources

While cannabis appears to be a tempting, and increasing, option for patients with pain, caution is still necessary as there is NO FDA approval for cannabis use in managing chronic pain and insomnia.  Studies in fibromyalgia and osteoarthritis are sorely needed. 

(The author disclosed that artificial intelligence was used to research and organize this content)