Cannabis and Chronic Non-Cancer Pain (CNCP)

May 29, 2019

Cannabis and Chronic Non-Cancer Pain (CNCP)

Dr. Matthew Green, Ph.D.

 

The prevalence of chronic pain reported among Canadians over the age of 18 is between 15 – 29%, with approximately 50% of those suffering for over 10 years1,2. Lower back pain is the most common type of pain, and arthritis the most common cause1. While considerable research has been conducted on the effects of cannabis on pain management, the greatest number of human clinical trials have focused on chronic non-cancer pain (CNCP), with a majority reporting a significantly greater reduction in pain (30% reduction) with cannabis use3,4.

Examples of CNCP include:

  • Neuropathic pain (central/peripheral),
  • Diabetic peripheral neuropathy
  • Fibromyalgia
  • HIV-associated sensory neuropathy
  • Refractory pain due to MS or other neurological condition
  • Rheumatoid arthritis (RA)
  • Musculoskeletal pain

How Cannabis Works in Pain Management

Cannabinoids, such as THC, act on cannabinoid receptors that are located throughout the body and are involved in relaying and processing sensory information from painful stimuli 8. Animal studies have shown that activation of cannabinoid receptors following a painful event has analgesic properties (e.g., neuropathic pain, inflammatory pain)7,9. While it is still unclear how exactly cannabinoids can lead to a reduction in pain, research suggests that their effects involve both CB1  and CB2  receptors, with some actions being tied to modulation of inflammatory responses7. More research involving placebo-controlled clinical trials are needed, however, to understand the actions and efficacy of cannabis/cannabinoids for treating chronic non-cancer pain.

Opiates and Cannabis in the Treatment of Pain

Opiates are among the most commonly prescribed medicines to combat chronic non-cancer pain, however they are also associated with high abuse and potential for overdosing5,6. There is  growing evidence that suggests cannabis may serve as a substitute for opiates in the treatment of chronic pain, and that when used in combination, provides greater relief then either treatment alone, thereby allowing for a reduction in the amount of opiates required7.

Given the evidence that cannabis may be an effective alternative to opioids, which have greater risk for abuse, cannabis may be useful as an adjunct treatment for reducing certain types chronic non-cancer pain. As with all medications, patients considering cannabis as a treatment for chronic pain should first speak to a health care practitioner to determine the options that are right for them and an appropriate treatment plan.

References

  1. Schopflocher et al. (2011). The prevalence of chronic pain in Canada. Pain Res Manage, 16(6), 445-450. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3298051/
  2. Boulanger et al. (2007). Chronic pain in Canada: Have we improved our management of chronic noncancer pain? Pain Res Manage 12: 39-47. https://www.ncbi.nlm.nih.gov/pubmed/17372633
  3. Stockings et al. (2018) Cannabis and cannabinoids for the treatment of people with chronic noncancer pain conditions: a systematic review and meta-analysis of controlled and observational studies Pain 159: 1932-1954. https://www.ncbi.nlm.nih.gov/pubmed/29847469
  4. Whiting et al. (2015) Cannabinoids for medical use: A systematic review and meta-analysis JAMA, 313: 2456-73. https://jamanetwork.com/journals/jama/fullarticle/2338251
  5. Canadian Drug Summary (2011). Canadian Centre on Substance Use and Addiction.
  6. Kim and Nelson (2015). Reducing the harm of opioid overdose with the safe use of naloxone: a pharmacologic review. Expert Opinion on Drug Safety 14: 1137-1146. https://www.ncbi.nlm.nih.gov/pubmed/25865597
  7. Manzanares et al. (2006). Role of the cannabinoid system in pain control and therapeutic implications for the management of acute and chronic pain episodes. Current neuropharmacology 4: 239-257. https://www.ncbi.nlm.nih.gov/pubmed/18615144
  8. Elikottil et al. (2009). The analgesic potential of cannabinoids. Journal of opioid management, 5(6), 341. https://www.ncbi.nlm.nih.gov/pubmed/20073408
  9. Richardson, J. D. (2000). Cannabinoids modulate pain by multiple mechanisms of action. The Journal of Pain 1: 2-14. https://www.sciencedirect.com/science/article/pii/S1526590000900828