A specific cannabis extract may relieve chronic lower back pain without causing addiction, according to a clinical trial published Monday that some experts say demonstrates for the first time that the substance, specially developed for this research, can treat pain.
According to the World Health Organization (WHO), lower back pain, which affects more than half a billion people worldwide, is the leading cause of disability.
But the medications used to treat this pain are limited to common pain relievers such as ibuprofen, which can have serious side effects with prolonged use, or opioids, which are highly addictive and can be dangerous.
The booming cannabis industry claims that a range of marijuana or cannabidiol (CBD) products can help relieve pain, but researchers say there have been no reliable studies supporting this efficacy.
- " Tremendous " -
On Monday, the results of a placebo-controlled phase 3 clinical trial—considered the gold standard in drug research—testing a cannabis extract were published in the journal Nature Medicine.
This trial involved more than 800 people whose chronic lower back pain was not relieved by medication: participants were asked to rate their pain level on a scale of 1 to 10, after taking this cannabis extract called VER-01, or a placebo, for a period ranging from 3 months to a year.
After 12 weeks, those who took the cannabis extract—a dose of VER-01 containing 2.5 milligrams of THC, the main active ingredient in marijuana—reported a 1.9-point reduction in pain, compared with a 0.6-point reduction for those who took the placebo.
After six months, participants taking the extract reported a further 2.9 points reduction in their pain. They also reported improvements in their sleep, physical abilities, and quality of life.
According to the study, the extract taken at this dose did not cause addiction or serious side effects. And the most commonly observed side effects—transient dizziness, drowsiness, dry mouth, and some nausea—reduced over time.
Matthias Karst, lead author of the study and professor of pain medicine at the Hannover Medical School in Germany, told AFP that no "euphoric effects" were observed during the trial.
Andrew Moore, a pain researcher at Oxford University who was not involved in the work and is now retired, told AFP that the "great" study was "the first to provide good-quality evidence that a component of cannabis can be useful in relieving pain."
– Call for caution –
However, Mr Moore urged caution over claims that the extract was not addictive, warning that such claims may have subsequently been invalidated in the past.
Additionally, the concentration and purity of cannabis products vary widely, making it difficult for doctors to safely prescribe them, Karst said.
And the VER-01 strain was specifically developed to be approved by medical authorities and prescribed for chronic pain, he added: so the trial doesn't prove that "all cannabis/CBD products would be equally useful," he said.
Jan Vollert, a pain researcher at the University of Exeter who was not involved in the study, also pointed out that this "very specific substance" was not similar to regular marijuana, comparing it to the differences between "hazelnuts" and "Nutella": "They may have a similar basis, but they are simply not comparable."
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