Liz Scherer
April 06, 2023
New clinical practice guidelines for cannabis in chronic pain management have been released.
Dr Alan Bell
Developed by a group of Canadian researchers, clinicians, and patients the guidelines note that cannabinoid-based medicines (CBM) may help clinicians offer an effective, less addictive, alternative to opioids in patients with chronic noncancer pain and comorbid conditions.
“We don’t recommend using CBM first line for anything pretty much because there are other alternatives that may be more effective and also offer fewer side effects,” lead guideline author Alan Bell, MD, assistant professor of family and community medicine at the University of Toronto, Toronto, Ontario, Canada, told Medscape Medical News.
“But I would strongly argue that I would use cannabis-based medicine over opioids every time. Why would you use a high potency-high toxicity agent when there’s a low potency-low toxicity alternative?” he said.
The guidelines were published online March 27 in the journal Cannabis and Cannabinoid Research.
Examining the Evidence
A consistent criticism of CBM has been the lack of quality research supporting its therapeutic utility. To develop the current recommendations, the task force reviewed 47 pain management studies enrolling more than 11,000 patients. Almost half of the studies (n = 22) were randomized controlled trials (RCTs) and 12 of the 19 included systematic reviews focused solely on RCTs.
Overall, 38 of the 47 included studies demonstrated that CBM provided at least moderate benefits for chronic pain, resulting in a “strong” recommendation — mostly as an adjunct or replacement treatment in individuals living with chronic pain.
Overall, the guidelines place a high value on improving chronic pain, functionality, and addressing co-occurring conditions such as insomnia, anxiety and depression, mobility, and inflammation. They also provide practical dosing and formulation tips to support the use of CBM in the clinical setting.
When it comes to chronic pain, CBM is not a panacea. However, prior research suggests cannabinoids and opioids share several pharmacologic properties, including independent but possibly related mechanisms for antinociception, making them an intriguing combination.
In the current guidelines, all of the four studies specifically addressing combined opioids and vaporized cannabis flower demonstrated further pain reduction, reinforcing the conclusion that the benefits of CBM for improving pain control in patients taking opioids outweigh the risk of nonserious adverse events (AEs), such as dry mouth, dizziness, increased appetite, sedation, and concentration difficulties.
The recommendations also highlighted evidence demonstrating that a majority of participants were able to reduce use of routine pain medications with concomitant CBM/opioid administration, while simultaneously offering secondary benefits such as improved sleep, anxiety, and mood, as well as prevention of opioid tolerance and dose escalation.
Importantly, the guidelines offer an evidence-based algorithm with a clear framework for tapering patients off opioids, especially those who are on > 50 mg MED, which places them with a twofold greater risk for fatal overdose.
An Effective Alternative
Commenting on the new guidelines for Medscape Medical News, Mark Wallace, MD, who has extensive experience researching and treating pain patients with medical cannabis, said the genesis of his interest in medical cannabis mirrors the guidelines’ focus.
“What got me interested in medical cannabis was trying to get patients off of opioids,” said Wallace, professor of anesthesiology and chief of the division of pain medicine in the department of anesthesiology at the University of California, San Diego. Wallace, who was not involved in the guidelines’ development study, said that he’s “titrated hundreds of patients off of opioids using cannabis.”
Wallace said he found the guidelines’ dosing recommendations helpful.
“If you stay within the 1- to 5-mg dosing range, the risks are so incredibly low, you’re not going to harm the patient.”
Dr Christopher Gilligan
While there are patients who abuse cannabis and CBMs, Wallace noted that he has seen only one patient in the past 20 years who was overusing the medical cannabis. He added that his patient population does not use medical cannabis to get high and, in fact, wants to avoid doses that produce that effect at all costs.
Also commenting on the guidelines, Christopher Gilligan, MD, MBA, associate chief medical officer and a pain medicine physician at Brigham & Women’s Hospital in Boston, Massachusetts, who was not involved in the guidelines’ development, points to the risks.
“When we have an opportunity to use cannabinoids in place of opioids for our patients, I think that that’s a positive thing…and a wise choice in terms of risk benefit,” Gilligan said.
On the other hand, he cautioned that “freely prescribing” cannabinoids for chronic pain in patients who aren’t on opioids is not good practice.
“We have to take seriously the potential adverse effects of [cannabis], including marijuana use disorder, interference with learning, memory impairment, and psychotic breakthroughs,” said Gilligan.
Given the current climate, it would appear that CBM is a long way from being endorsed by the US Food and Drug Administration, but for clinicians interested in trying CBM for chronic pain patients, the guidelines may offer a roadmap for initiation and an alternative to prescribing opioids.
Bell, Gilligan, and Wallace report no relevant financial relationships.
Cannabis Cannabinoid Res. Published online March 27, 2023.
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