Cannabis for Multiple Sclerosis Pain

Nearly one-third of adults with multiple sclerosis report using cannabis for pain management, with oil or tincture being the preferred method of administration, based on data from more than 200 individuals.¹

Cannabis continues to gain popularity as a pain management option, and its use has extended to patients with multiple sclerosis (MS), but data characterizing the types of cannabis products used and the characteristics of people who use them are lacking, wrote Kara Link, a PhD candidate at the University of Washington, Seattle, and colleagues in a recent study.¹

Previous studies of cannabis products used by individuals with MS have been limited in scope and stand out of date with changes in the legality of cannabis products; therefore, a current review was needed, they noted.

Analysis of Cannabis Use in MS

Methods

In their study, published in Multiple Sclerosis and Related Disorders, Link et al conducted a secondary analysis of adults aged 18 years and older (mean age 52.9 years) with confirmed MS diagnoses who were enrolled in an RCT of mindfulness-based cognitive therapy (MBCT), cognitive-behavioral therapy (CBT), and usual care for chronic pain.

Cannabis products were classified as edible, oil/tincture, smoked, tablet/pill/capsule, topical, vaped, or unknown.

The researchers compared cannabis users and non-users in terms of several pain-related variables including pain intensity, pain interference, neuropathic pain, pain medication use, and pain-related coping. To assess differences among cannabis users and nonusers, they used several statistical methods including t-tests, Mann-Whitney tests, chi-square tests, and Fisher’s exact tests.

Findings

Overall, 65 of the 242 study participants (27%) reported using cannabis for pain management. Of these, 42% reported using oil or tincture, 22% reported vaping, and 17% reported use of edible products. A total of 14 cannabis users (22%) reported more than one method of use, and 10 products were categorized as unknown by the participants.

Those who used cannabis were significantly younger than those who did not, with a median age of 51 years vs. 55 years (P=0.019). Cannabis users also reported significantly higher median scores of pain intensity (6.0 vs. 5.0, P=0.022), higher median scores of pain interference (5.9 vs. 5.4, P =0.027), and higher median neuropathic pain levels (20.0 vs. 16.0, P=0.001) compared to nonusers. Pain intensity was measured using an 11-point numeric rating scale (NRS) of 0 to 10. Pain interference was measured using the Brief Pain Inventory – Pain Interference Scale (BPI-I). Neuropathic pain was assessed using the painDETECT questionnaire.

Measures of pain catastrophizing, pain anxiety symptoms, and chronic pain acceptance were not significantly different between cannabis users and non-users.

“The 27% prevalence of current cannabis use in this sample exceeds the prevalence of current use in older studies of people with MS,” by more than double, the researchers wrote in their discussion. “It is unknown whether the increase in current use is due to greater use, more comfort in reporting use now that cannabis is legal in many states, or a combination of these or other factors.”

The findings were limited by several factors including the cross-sectional design, the researchers noted. Other limitations included the lack of collection of data that could explain motivation for cannabis use more specifically than general “pain management.” The study also was not designed to examine differences in pain management outcomes between cannabis users of THC or CBD-dominant products.

The study is, however, the first known to examine profiles of individuals with MS who use cannabis for pain. More work is needed, especially longitudinal studies to explore trends in cannabis use for pain management, as well as the effects of cannabis use on pain-related outcomes over time, they concluded.

Related Data on Cannabis for MS-Related Pain

Although the demand for alternative pain management strategies for MS patients is high, the clinical evidence supporting the effectiveness of cannabis on pain in this population is limited, according to the authors of a 2022 Cochrane Review, “Cannabis and cannabinoids for symptomatic treatment for people with multiple sclerosis.”²

In this review, Filipini et al identified 25 RCTs of cannabinoid use in MS patients. Of these, only one small study (from 2004) assessed neuropathic pain relief in MS.³ The difference in pain relief was significant for cannabis users compared to placebo. However, the study included only 24 patients, and the reviewers described it as “very low-certainty evidence” for whether cannabinoid use reduces the intensity of chronic neuropathic pain.³

In the small study cited in the review, published in the British Medical Journal by Svendsen et al, 24 adults aged 23 to 55 years with MS and central pain were randomized to 3 weeks’ (18 to 21 days) treatment with oral dronabinol at a maximum of 10 mg daily, then crossed over for 3 weeks (18 to 21 days) treatment with placebo capsules, with a washout period of at least 21 days between the two treatment periods.³

The primary outcome was median spontaneous pain intensity in the last week of the treatment period. The researchers found no significant carryover effect for this outcome, but the median spontaneous pain intensity was significantly lower during the last week of dronabinol treatment compared with placebo (4.0 vs. 5.0, P=0.02).³

Despite the small size, the level of pain reduction was similar to the effect of other drugs used to treat neuropathic pain conditions, the researchers noted.

Although more studies are needed, the findings suggest that dronabinol should be available for patients with MS whose central pain is not adequately controlled by other drugs such as anticonvulsants, antidepressants, and opioids, they said.

Disclosures: The study by Link and colleagues was supported by the National Multiple Sclerosis Society. The study by Svendsen and colleagues was supported by the Danish Multiple Sclerosis Society, a grant from manager Ejnar Jonasseon and his wife’s memorial grant, and the Warwara Larsen Foundation, Denmark. Solvay Pharmaceuticals provided study medication and placebo, and financial support for study monitoring and data analysis.