Tuesday November 10, 2020
pic of cannabis leaf and author Kylie Nabata
People with spinal cord injuries (SCI) commonly experience pain and spasticity, as well as other issues including difficulties performing activities of daily living, pressure sores, and cardiorespiratory problems. Limitations of current treatments have generated interest in medicinal cannabis as a possible therapy. Cannabis is currently legalized in Canada and in parts of the United States. Public acceptance of cannabis for both medical and recreational purposes is increasing, with a recent survey reporting that two-thirds of medical cannabis users felt support from friends and family.
SCIRE authors Janice Eng and Matthew Querée with Dr. Andrei Krassioukov and members of his lab at ICORD recently conducted the world’s first systematic review focused on cannabis and its therapeutic potential for people with SCI.
The most important findings are:
– Four randomized controlled trials (RCTs) found that cannabis significantly reduced pain compared to a placebo in people with SCI.
– Two RCTs found that some dosages of cannabis reduced spasticity in people with SCI compared to a placebo.
There were many more survey studies found that did not test the effects of cannabis but rather asked people with SCI about their experience using cannabis. Most of these studies reported that people with SCI experienced a mild, moderate or complete reduction in spasticity, a mild to moderate reduction in pain, and that participants preferred cannabis to other pain relieving medication (e.g., opioids) primarily due to fewer and less severe side effects. However, cannabis also has side effects though most are mild to moderate in severity. In these same studies, people with SCI reported a variety of side effects from cannabis use including fatigue or drowsiness, memory-concentration disturbances, abdominal discomfort, increased hunger, dry mouth, and itchiness.
Results should be interpreted with caution, however, for several reasons. Even the experimental studies we found had some methodological issues, including small sample sizes and using a variety of ways to measure study outcomes. The greatest variability in all studies found was the type, concentration and dosage of cannabis used (e.g., THC:CBD ratios, percentages, concentrations); only two of 22 studies reported mean dosage of cannabis administered. Without standardization in types and dosages of cannabis tested, it is difficult for health care practitioners to prescribe or recommend cannabis as they would with other medications.
As cannabis has only been legal for a short time, we expect better studies with standardized concentrations and dosages will be conducted soon. It will also be important for studies to be longer in duration, allowing researchers to monitor any lingering side effects, cognitive deficits that develop, and ensure the safety and clinical significance of cannabis usage for people with SCI.
Kylie Nabata, BSc., a medical student at the University of British Columbia, was the lead author of ‘The Therapeutic Potential and Usage Patterns of Cannabis in People with Spinal Cord Injuries: A Systematic Review’.
Full citation: Nabata KJ, Tse EK, Nightingale TE, Lee AHX, Eng JJ, Querée M, Walter M, Krassioukov AV. The Therapeutic Potential and Usage Patterns of Cannabinoids in People with Spinal Cord Injuries: A Systematic Review. Current Neuropharmacology. 2020 Apr 19. doi: 10.2174/1570159X18666200420085712. Online ahead of print.