March 1, 2018
Medical cannabis study shows significant number of patients saw pain reduction of 30 percent or more
Forty-two percent of Minnesota’s patients taking medical cannabis for intractable pain reported a pain reduction of thirty percent or more, according to a new study conducted by the Minnesota Department of Health.
“This study helps improve our understanding of the potential of medical cannabis for treating pain,” said Minnesota Health Commissioner Jan Malcolm. “We need additional and more rigorous study, but these results are clinically significant and promising for both pain treatment and reducing opioid dependence.”
The first-of-its-kind research study is based on the experiences of the initial 2,245 people enrolled for intractable pain in Minnesota’s medical cannabis program from August 1, 2016 to December 31, 2016. Of this initial group, 2,174 patients purchased medical cannabis within the study’s observation period and completed a required self-evaluation before each purchase.
As part of the self-evaluation, patients completed the PEG (pain, enjoyment and general activity) screening tool. On a scale of 0 to 10 (with 0 being no pain and 10 being the highest pain), patients rated their level of pain, how pain interfered with their enjoyment of life and how pain interfered with their general activity.
Using the PEG scale data, 42 percent of the patients who scored moderate to high pain levels at the beginning of the measurement achieved a reduction in pain scores of 30 percent or more, and 22 percent of patients both achieved and maintained a reduction of 30 percent or more over four months. The 30 percent reduction threshold is often used in pain studies to define clinically meaningful improvement.
Health care practitioners caring for program-enrolled patients suffering from intractable pain reported similar reductions in pain scores, saying 41 percent of patients achieved at least a reduction of 30 percent or more.
The study also found that of the 353 patients who self-reported taking opioid medications when they started using medical cannabis, 63 percent or 221 reduced or eliminated opioid use after six months. Likewise, the health care practitioner survey found that 58 percent of patients who were on other pain medications were able to reduce their use of these medications when they started taking medical cannabis. Thirty-eight percent of patients reduced opioid medication (nearly 60 percent of these cut use of at least one opioid by half or more), 3 percent of patients reduced benzodiazepines and 22 percent of patients reduced other pain medications.
The safety profile of medical cannabis products available through the Minnesota program continues to appear favorable. No serious adverse events (life threatening or requiring hospitalization) were reported for this group of patients during the observation period.
About 40 percent of patients reported adverse side effects and of those that did report adverse side effects, about 90 percent said those side effects were mild to moderate. Common adverse effects included dry mouth, drowsiness, fatigue and mental clouding/“foggy brain.”
Fifty-five patients taking medical cannabis for intractable pain reported severe adverse side effects, meaning side effects that interrupted usual daily activities. The assessment of this patient feedback found no apparent pattern in patient age, primary cause of pain or type of medical cannabis product used.
Pain patients also reported improvements related to sleep and reduced anxiety.
“These survey results are a good starting point,” said Dr. Tom Arneson, research manager for the office of medical cannabis. “We need more research into the potential value of medical cannabis in pain management, especially as our communities grapple with the harmful impacts of opioids and other medications now in use for that purpose. We encourage health care providers to read the full report as they consider whether medical cannabis should be part of their strategies for treating patients’ intractable pain.”
Intractable pain, as defined by state law, is a state of pain in which the cause cannot be removed and, according to generally accepted medical practice, the full range of pain management treatments appropriate for the patient have been used without adequate result or with intolerable side effects.
The MDH Office of Medical Cannabis relies on the professional judgment of the certifying health care practitioner as to whether the full range of treatments for an individual patient have been sufficiently used to meet the program’s definition of intractable pain. For example, it is not necessary for a patient to have tried opioid medications.
Minnesota Department of Health Communications