Medical cannabis is conditionally condoned in many countries including Bangladesh, Canada, Columbia, Finland, Germany, Italy, North Korea, Poland, Portugal, Spain, Sweden, the United Kingdom, Uruguay and in much of the United States. Although there have been a wide variety of indications in the past few decades for which medical cannabis has been purported to be both efficacious and safe (e.g. glaucoma), the most common use of medical cannabis today is for chronic pain. There is a developing basic science evidence base linking the cannabinoid neurotransmitter system to nociception. The cannabinoid (CB1) receptors are localized in several structures important for pain like the periaqueductal gray, spinal trigeminal nucleus, amygdala, and basal ganglia. Endogenous retrograde signaling molecules anandamide and 2-arachidonlyglycerol, or exogenous tetrahydocannabinol (THC), bind presynaptic CB1 receptors and inhibit neurons that are engaged by pain. The CB2 receptors, localized outside of the central nervous system, have also been implicated in pain management. Importantly, other cannabinoids besides THC also contribute to the nociceptive properties of medical cannabis.
Chronic pain is a complex construct which has cellular, anatomical, and psychological substrates and has been proposed to be viewed within a biopsychosocial lens. Pain, and especially chronic pain, exists within a context of biological and psychological variables such as genetics, gender, sleep, stress, and others. Despite extensive research and efforts at treating chronic pain, the efficacy of most pharmacologic and interventional modalities is incomplete. Increasingly, it is recognized that there is heterogeneity and overlap in chronic pain conditions. Pain management strategies are often limited by variable efficacy, side effects, toxicity and safety concerns, addiction, and expense. As such, the search continues for effective, safe, and ideally affordable treatments for chronic pain.
Medical cannabis, like all drugs, exists within a socio-cultural environment that incorporates historical, legal, and extra-nociceptive elements which influences the perceptions of both patients and healthcare providers. Surveys have consistently identified efficacy in symptom management and improved quality of life with medical cannabis. The majority of Australians indicated that cannabis provided “great relief” (55%) or “good relief” (45%) from pain.
The largest positive theme identified related to health benefits. Respondents from the survey described in great depth how medical cannabis improved their treatment of chronic-pain and enhanced their quality of life. These results are consistent with prior quantitative examinations of medical cannabis among patients from the United Kingdom, Canada, and Australia, as well as more regionally focused efforts in the US. In addition to pain, the next most frequent health benefit was to improve sleep. Sleep impairments such as problems falling asleep and sleep maintenance are commonly experienced by patients with chronic pain. However, sleep disruption (including nightmares) is also an important component of Post-Traumatic Stress Disorder (PTSD symptomology and one-quarter of this sample had been diagnosed with PTSD.
Overall, this report identified many beliefs about the efficacy, and cost, of MC among patients. Independent of an individual providers, or their institutions, views about MC or its evidence base, an awareness of patients’ perspectives about these topics could enhance an open-discussion about MC and its role as part of a multimodal approach to chronic pain. Although this study is limited in some ways, it does provide a window into the chronic pain patient’s favorable and unfavorable experiences with MC. It is increasingly apparent that the patient’s perspective is important.
Excerpt from ncbi.nlm.nih.gov/pmc/articles/PMC5845915/
Piper, Brian J et al. “Chronic pain patients’ perspectives of medical cannabis.” Pain vol. 158,7 (2017): 1373-1379. doi:10.1097/j.pain.0000000000000899