Israeli researchers have found that medical cannabis can significantly ease lower-back pain, but that not all types of marijuana do the job.
Four out of five people have lower back pain at some point in their lives, making it one of the most common reasons people visit their doctors. It usually gets better within a few weeks but may become chronic, with pain ranging from mild to severe, making it difficult or impossible to walk, work, sleep or carry out routine activities.
People over the age of 30 – especially those who are overweight or have jobs with a lot of lifting and bending, diseases like osteoarthritis or scoliosis and poor posture – are at high risk for such pain. Treatments include cortisone injections, manipulation, physical therapy and even surgery.
Dr. Dror Robinson and Dr. Mustafa Yassin of the Orthopedics Department of Hasharon Hospital of the Rabin Medical Center in Petah Tikva, and Sivan Ritter of the University of Haifa, published their new study in the Rambam Maimonides Medical Journal published online by the Rambam Health Care Campus under the title “Comparing Sublingual and Inhaled Cannabis Therapies for Low Back Pain: An Observational Open-Label Study.”
Driven by public demand, medical cannabis is growing as a common treatment in medicine, especially for pain relief, despite the lack of established scientific basis, they wrote.
Two types of cannabis treatment were given to chronic low-back-pain patients. The first was cannabidiol (CBD)-rich sublingual (under the tongue) extract treatment over a period of 10 months.
After a month of no treatment, the same group received Δ9-tetrahydrocannabinol (THC)-rich whole dried cannabis flowers that were smoked in the form of cannabis cigarettes for 12 months. Oral consumption in the form of edibles such as cookies is reserved for children and was not relevant to this group of adult patients.
The number of participants was small – 24 people, seven women and 17 men, whose MRI or CT scans of the spine showed disc herniation or spinal stenosis – but the results were convincing. The most commonly reported initial side effects were nausea, sore throat, drowsiness, dizziness and fatigue, all of which were transient and disappeared after dose tolerance was achieved. Most of these adverse effects were noted in female patients.
Just three patients dropped out of extract therapy treatment but resumed study participation to receive THC-rich smoking therapy. After a minimum of two years, the sublingual extract treatment was not significant in reducing pain, but it was impressive when the cannabis flowers were smoked.
“Our findings indicate that inhaled THC-rich therapy is more effective than CBD-rich sublingual extract therapy for treating low back pain and that cannabis therapy is safe and effective for chronic low back pain," the team concluded.
A recent survey of over 1,000 North American adults who self-administered cannabis for chronic pain found that 58% of those surveyed used it to ease back pain, 36% used inhalation therapy, 45% used both inhalation and non-inhalation therapy, and 19% used non-inhalation therapy only.
Cannabis use in Israel
The differences in cannabis usage between Israel and North America, suggested the authors, may be attributed to the greater variety of legally available medical cannabis products in the US and Canada such as edibles and high-concentration THC, which are not permitted in Israel.
Currently, active medical cannabis licenses have been issued to 110,971 Israelis, and 56.6% of such licenses were prescribed to treat chronic neuropathic non-cancer pain.
“A major obstacle to the widespread legal use of medical cannabinoid-based (CB) therapy is the lack of sufficient evidence-based data. However, the naturally occurring variation among and between the phytoconstituents of different cannabis cultivars makes it difficult to quantitate and compare studies and subjects,” they wrote.
Treating pain with sublingually administered cannabis extracts is preferred by many doctors, as it may be regarded as easier to obtain from the pharmacy and to consume. Sublingual administration might also have the benefit of a more consistent dosing regimen while avoiding the adverse effects of smoking.
But the authors’ real-world clinical experience “indicates a relative lack of efficiency of sublingual extract treatments compared to smoking.” Most Israeli patients seem to prefer smoking cannabis to extract consumption for pain relief. The Health Ministry’s licenses granted to patients included just 10% for sublingual extracts and 90% for smoked cannabis flowers.