Medical Cannabis and Back Pain: Opioid Use Has Dropped by 90 % in 10 Years

A ten-year study conducted in Israel suggests that treatment with medical cannabis could be associated with a substantial and lasting reduction in the opioid use in patients with chronic back pain.

The researchers also observed significant improvements in pain intensity and functional disability, although the observational nature of the study does not allow for the establishment of a direct causal relationship.

Published in the’European Spine Journal, this study followed 1,000 patients with chronic low back pain who had never used cannabis before. The participants were recruited through an orthopedic clinic specializing in pain management and were followed up annually for ten years.

Opioid use has fallen by nearly 90 % over the past ten years

Researchers from the’Tel Aviv University, from Rabin Medical Center and Clalit Health Services reported an 89.8% reduction in opioid use, measured in milligrams of morphine equivalent, over the course of the study.

According to the researchers, this decline occurred particularly rapidly after the start of treatment with the medical marijuana : «Opioid use declined rapidly during the first year and remained stable through the tenth year.»

Among the participants, 91 % met the threshold predefined by the study, namely a reduction of at least 50 % in opioid use.

The changes were not limited to prescription pain relievers. Researchers reported an 84.2 % reduction in pain intensity and a 30.4 % decrease in functional disability. Approximately 62 % of the patients achieved the predefined clinically significant improvement in pain, while the same proportion achieved the target for functional disability.

«Medical cannabis treatment has been associated with a reduction in opioid use, pain intensity, and functional disability over a 10-year period, accompanied by a decrease in polypharmacy and acceptable tolerability.»

The use of other prescription medications has also decreased

The study also highlighted substantial changes in terms of polypharmacy, an important issue for people undergoing long-term treatment for chronic pain.

The consumption of tramadol or tapentadol use decreased from 89.7 % of participants to 5.6 %, while benzodiazepine use fell from 78.8 % to 5.3 %. The proportion of patients taking SSRIs fell from 77.7 % to 5.8 %, and the use of gabapentinoids dropped from 31.3 % to just 0.6 %.

According to the authors, these changes were not mandated by the study protocol. On the contrary, the treatment adjustments resulted from decisions made jointly by each patient and their doctor, based on their symptoms and their response to treatment.

Researchers suggest that this trend could indicate that the medical marijuana It affects several aspects of the symptoms commonly associated with chronic pain, including pain itself, sleep disturbances, anxiety, and depression. However, the study does not demonstrate that cannabis is directly responsible for the decrease in use across each of these categories of medications.

Participants used various cannabis-based preparations, including dried flowers administered via vaporization and oils taken orally or sublingually.

Significant limitations behind these striking results

Despite the scope and duration of these findings, the authors call for caution in interpreting them.

Of the initial 1,000 participants, 638 completed the final 10-year follow-up. More importantly, this study was a single-arm observational study, which means there was no randomized control group against which to compare the results.

Consequently, the researchers explicitly acknowledge that no causal link can be established. They also note that the improvements observed were considerably greater than those typically reported in randomized controlled trials, raising the possibility that observational biases may have contributed to these results.

This study stands out, however, for the length of its follow-up period. According to its authors, it is the longest study specifically focusing on Medical Treatment of Chronic Low Back Pain with Cannabis.

These findings add to a growing body of research aimed at determining whether cannabis-based treatments could play a role in the chronic pain management and potentially reduce the use of opioids and other prescription medications.