Pain: Cannabinoids and CBD Research Overview

Pain is a feeling of discomfort that develops after an injury, illness or chronic health condition. Studies have shown cannabinoids are highly effective at lowering all types of pain, including the pain that’s shown to be resistant to other treatments.

Overview of Pain

Pain, which is an unpleasant sensory experience, is designed as a warning system that something in the body is wrong. It can be experienced as a prick, tingle, burn, ache or sting. Pain has the capability of limiting productivity and adversely affecting one’s well-being. Pain is subjective, and according to the National Institute of Neurological Disorders and Stroke, genetics can influence a person’s’ risk for developing pain, as well as how sensitive one is to painful stimuli and whether certain therapies will help alleviate discomfort.

Pain is classified as either acute or chronic. Acute pain is primarily the result of disease, injury or inflammation. It typically comes on suddenly and often subsides once its cause is identified and treated. Chronic pain is the discomfort associated with a chronic disease and it can persist over a long period of time and is often resistant to many medical treatments. Chronic pain can cause serious problems and severely affect a person’s quality of life.

Pain is further classified as nociceptive, neuropathic or psychogenic. Nociceptive pain (“somatic” or “visceral”) is due to the ongoing activation of pain receptors in either the surface or deep tissues of the body and is often associated with inflammation. Examples of conditions that can cause nociceptive pain include fibromyalgia, rheumatoid arthritis, inflammatory bowel diseases, HIV and AIDS, and cancer. Neuropathic pain is attributed to changes in the nervous system that sustain a painful sensation even after an injury is healed. Psychogenic pain is due to a psychological disturbance that causes anxiety or depression.

Pain is typically treated with a variety of medications, which could include acetaminophen, non-steroidal anti-inflammatory agents, and opioids. Opioids, like morphine, are effective at treating most pain but often come with side effects like constipation, nausea, and vomiting, and are highly addictive.

Findings: Effects of Cannabinoids and CBD on Pain

The cannabinoids found in cannabis, tetrahydrocannabinol (THC) and cannabidiol (CBD), have been found effective at lowering pain levels associated with some cancer, neuropathy, spasticity, headache, migraines, and other acute pain and chronic pain conditions^1,4. THC and CBD are able to help in the management of pain because they interact with the two main cannabinoid receptors (CB₁ and CB₂) of the endocannabinoid system within the body. These receptors regulate the release of neurotransmitter and central nervous system immune cells to manage pain levels¹².

The studies supporting cannabis’ effectiveness as a pain reliever are vast. Cannabis has demonstrated the ability to significantly lower pain levels in patients suffering from neuropathic and nociceptive pain, and has even shown it can help manage pain that has proven refractory to other treatments^2,5,8. As a result, cannabis use has been found to be prevalent among the chronic pain population, with improvements in pain, sleep and mood being the most frequently reported reasons for use⁹. One study found that in HIV-positive patients, 94% reported an improvement in muscle pain and 90% reported an improvement in nerve pain after cannabis use¹³. In another study, 12 of 15 chronic pain patients who smoke herbal cannabis for therapeutic reasons reported an improvement in pain¹⁰. A survey study found that most sufferers of chronic pelvic pain syndrome reported that using cannabis improved their pain⁷.

Studies have also demonstrated that using cannabis for the management of pain is safe. After a year of regular use, patients with chronic pain were found to be at no greater risk of serious adverse effects than non-cannabis users¹¹.

Despite the clear pain relief benefits that cannabinoids can offer, health care providers continue to be hesitant to prescribe medical Cannabis for their patients. Just 27% of the health professionals legally allowed to write cannabinoids authorizations in the state of Washington had issued the prescriptions because of a lack of education on scientific basis of cannabinoids or training on the best clinical practices of cannabinoids, according to a 2015 study³.

States That Have Approved Medical Cannabis for Pain

Nearly all states with medical cannabis laws have approved medicinal cannabis specifically to treat “chronic pain.” These states include: Alaska, Arizona, California, Colorado, Delaware, Hawaii, Maine, Maryland, Michigan, Montana, New Hampshire, New Mexico, Ohio, Oregon, Pennsylvania, Rhode Island, and Vermont. The states of Nevada, New Hampshire, Ohio, Vermont, and West Virginia allow medical cannabis to treat “severe pain.” The states of Minnesota, Ohio, Pennsylvania, and Washington have approved cannabis for the treatment of “intractable pain.”

Two additional states will consider allowing medical cannabis to be used for the treatment of pain with recommendation by a physician. These states include: Connecticut (other medical conditions may be approved by the Department of Consumer Protection) and Massachusetts (other conditions as determined in writing by a qualifying patient’s physician).

In Washington D.C., any condition can be approved for medical cannabis as long as a DC-licensed physician recommends the treatment.

Recent Studies on Cannabinoids and CBD’s Effect on Pain

Twelve of 15 chronic pain patients who smoke herbal cannabis for therapeutic reasons reported an improvement in pain.
Cannabis for chronic pain: case series and implications for clinicians.
(http://www.ncbi.nlm.nih.gov/pubmed/12185373)

Using cannabis has been shown to significantly improve neuropathic pain that had proven refractory to other treatments.
The effectiveness of cannabinoids in the management of chronic nonmalignant neuropathic pain: a systematic review.
(http://www.ncbi.nlm.nih.gov/pubmed/25635955)

Resources:

1. Baron, E.P. (2015, June). Comprehensive Review of Medicinal Cannabis, Cannabinoids, and Therapeutic Implications in Medicine and Headache: What a Long Strange Trip It’s Been… Headache, 55(6), 885-916.
2. Boychuck, D.G., Goddard, G., Mauro, G., and Orellana, M.F. (2015 Winter). The effectiveness of cannabinoids in the management of chronic nonmalignant neuropathic pain: a systematic review. Journal of Oral & Facial Pain and Headache, 29(1), 7-14.
3. Carlini, B.H., Garrett, S.B., and Carter, G.T. (2015, September). Medicinal Cannabis: A Survey Among Health Care Providers in Washington State. The American Journal of Hospice & Palliative Care. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/26377551.
4. Jensen, B., Chen, J., Furnish, T., and Wallace, M. (2015, October). Cannabinoids and Chronic Pain: a Review of Basic Science and Clinical Evidence. Current Pain and Headache Reports, 19(10), 524.
5. Lynch, M.E., and Campbell, F. (2011, November). Cannabinoids for treatment of chronic non-cancer pain; a systematic review of randomized trials. British Journal of Clinical Pharmacology, 72(5), 735-744.
6. Pain: Hope Through Research (2015, September 4). National Institute of Neurological Disorders and Stroke. Retrieved from http://www.ninds.nih.gov/disorders/chronic_pain/detail_chronic_pain.htm.
7. Tripp, D.A., Nickel, J.C., Katz, L., Krsmanovic, A., Ware, M.A., and Santor, D. (2014, November). A survey of cannabis (Cannabis) use and self-reported benefit in men with chronic prostatitis/chronic pelvic pain syndrome. Canadian Urological Association Journal, 9(11-12).
8. Wallace, M.S., Marcotte, T.D., Umlauf, A., Gouaux, B., and Atkinson, J.H. (2015, July). Efficacy of Inhaled Cannabis on Painful Diabetic Neuropathy. Journal of Pain, 16(7), 616-27.
9. Ware, M.A., Doyle, C.R., Woods, R., Lynch, M.E., and Clark, A.J. (2003, March). Cannabis use for chronic non-cancer pain: results of a prospective survey. Pain, 102(1-2).
10. Ware, M.A., Gamsa, A., Persson, J., and Fitzcharles, M.A. (2002, Summer). Cannabis for chronic pain: case series and implications for clinicians. Pain Research & Management, 7(2), 95-9.
11. Ware, M.A., Wang, T., Shapiro, S., and Collet, J.P. (2015, September 15). Cannabis for the Management of Pain: Assessment of Safety Study (COMPASS). The Journal of Pain. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/26385201.
12. Woodhams, S.G., Sagar, D.R., Burston, J.J., and Chapman, V. (2015). The role of the endocannabinoid system in pain. Handbook of Experimental Pharmacology, 227, 119-43.
13. Woolridge, E., Barton, S., Samuel, J., Osario, J., Dougherty, A., and Holdcroft, A. (2005, April). Cannabis use in HIV for pain and other medical symptoms. Journal of Pain and Symptom Management, 29(4), 358-67.