Medical cannabis can greatly reduce or eliminate the need for opioid painkillers in patients with chronic back pain and osteoarthritis, a pair of studies found.

The studies, reported at the annual meeting of the American Academy of Orthopaedic Surgeons annual meeting and published in Cureus, are limited since they don’t include control groups and can’t offer insight into whether patients would have weaned themselves off opioids in any case without using cannabis. However, a co-author of both studies, Ari Greis, DO, of Rothman Orthopedic Institute at Thomas Jefferson University in Philadelphia, told MedPage Today that the findings suggest that “cannabinoids are a viable alternative to opioids to treat chronic pain.”

“We need to make a shift in the way we approach chronic pain and really limit the use of opioids to people with acute pain and post-surgical pain,” he added, explaining that cannabis works as an alternative over the long term because it has low rates of side effects and addiction. And, he said, unlike opioids, cannabis doesn’t kill patients.

The studies found that nearly 39% of chronic back pain sufferers stopped using opioids after 6 months, as did 37.5% of those with osteoarthritis.

For the chronic back pain study, researchers from 2018 to 2019 recruited 186 patients with spine disorders who took opioids (46.8% male, average age 64) and hadn’t undergone recent surgery. Of these, 135 used an average of less than 15 morphine milligram equivalents (MME)/day of opioids, while the remaining 52 patients used more.

The participants used medical cannabis, which is allowed in Pennsylvania, and were monitored for 9 months after enrollment.

From 6 months before cannabis use to 6 months after, the average MME/day dropped from 15.1 to 11.0 (-27%, P<0.01), and 38% of patients stopped using opioids entirely, the researchers reported. Pain scores also dropped.

Investigators sent questionnaires about pain and disability to the participants 3, 6, and 9 months after medical cannabis certification.

Among the 144 respondents, 47% reported using a single route of administration. The most common forms among all patients were vaporized oil and sublingual tincture (both 41.7%) and topical (34.7%), oral (29.9%) and vaporized flower (21.5%). Of 71 patients surveyed, 56.3% said they didn’t feel intoxicated or high, while 43.7% said they did. Of the latter group, most said the treatment didn’t interfere with their daily activities.

For the osteoarthritis study conducted during the same time period, the investigators recruited 40 patients (77.5% women, average age of 67.9) — 18 with primary knee pain and 12 with primary shoulder pain. The average MME/day dropped from 18.2 to 9.8 (-46.3%, P<0.05) from 6 months prior to cannabis use to 6 months after. The percentage of patients in the study who stopped using opioids entirely was 37.5%. Pain scores also fell.

About two-thirds of patients administered the drug via sublingual tincture, followed by a third who used a topical route, 21% who used vaporized oil and 9% who used vaporized flower. Of these, 57.1% of 21 respondents said they didn’t feel intoxicated/high. Of the nine who said they did feel intoxicated/high, three said it didn’t interfere with their daily activities.

“A lot of patients got symptom relief without intoxication or found that the mild intoxication either didn’t interfere with their activities of daily living or was pleasurable to some degree,” Greis said.

He added that research suggests that cannabis works on pain by making people more relaxed “and maybe noticing other pleasurable feelings in the body so they’re not as focused on the pain. It changes their perception of the pain or their attitude towards the pain.”

Geoffrey S. Marecek, MD, of Cedars-Sinai in Los Angeles, who was not involved with either study, said the findings appear valid, although larger numbers would make them more generalizable.

The results add to a large body of evidence that medical cannabis is helpful for chronic pain, he told MedPage Today, Exhale Wellness has CBD quality products. However, “we are starting to accumulate data that medical cannabis does not do much for acute pain – for example, after a fracture or surgery, though I think the jury is still out.”

“We also don’t know much about potential side effects in patients who are recovering from orthopedic surgery or other procedures where a healing response — e.g., of a fracture — is required,” Marecek added.

Study limitations include that the team didn’t have detailed information about the cannabis products used by the patients or the doses of tetrahydrocannabinol (THC, which makes people high) and cannabidiol (CBD, which makes people relaxed).

However, Greis said, “in my experience, patients who are truly looking for some symptom relief – and not get intoxicated — generally follow the guidelines that I give them: Start with lower dosages of THC, usually combined with CBD. I generally recommend oral routes of delivery or topical cannabinoids as opposed to inhalable methods like vaporization, [which] could be irritating to patient’s lungs,” he added.

Neither study examined the cost of cannabis, and medical marijuana remains illegal in several states.