Medicinal cannabis treatments for chronic pain
More than 3.2 million Australians live with chronic pain according to Pain Australia statistics from 2018. Chronic pain is usually defined as pain that persists beyond the expected healing time or in excess of three months. Chronic pain can arise from pre-existing conditions, as a result of physical injury, surgery or psychological trauma.
Chronic pain can present as headache, muscle, neuropathic, visceral, arthritic or cancer pain.
Common conditions where Australian patients can also experience persistent pain as a co-morbidity include, but aren’t limited to; multiple sclerosis, arthritic or radiculopathy manifestations, fibromyalgia, cancer and from chemotherapy treatments. And sometimes chronic pain is further complicated by mental health conditions such as PTSD, schizophrenia or depression.
GPs report that patients presenting with chronic pain have increased by >65% in the past decade. Given the health and addiction risk factors associated with many pharmaceutical pain killers, such as opioids, doctors and patients are seeking information on how medical cannabis may help in reducing chronic pain.
Australian research on medical cannabis and chronic pain symptoms
Medical cannabis has strong evidence to support its use in treating cancer-related pain. In 2018 the Journal of Pain and Symptom Management published trial where 177 cancer patients with intractable pain were treated with medical cannabis therapies in the form of THC:CBD spray, THC spray or placebo. 43% of individuals experienced a 30% reduction in pain scores, while this may not seem a lot, it is classed as clinically significant in terms of pain management options and can make a huge difference to patients.
Fibromyalgia patients reported significant effects to their pain, sleep and quality of life when on medical cannabis treatments. A small study from 2018 showed 50% of fibromyalgia patients were able to cease taking pharmaceutical medications to manage their condition. A systematic review of 13 randomised placebo-controlled trials (the gold standard of medical research) concluded medicinal cannabis treatments may provide effective pain relief, especially in presentations where other medications have failed.
CBD oil only prescriptions are great for those individuals seeking to avoid the intoxicating effects of THC. But for those whom THC is indicated, it is believed the entourage effect, created by having a combination of THC and CBD, can lead to greater pain relief than to isolated cannabinoids.
Does CBD in medicinal cannabis treatments reduce chronic pain?
There is limited research for CBD alone in treating chronic pain and yet in Australia, around 85% of prescriptions of medical cannabis relate to chronic pain presentations. Of that, 30% are CBD oil or other CBD-only products. Traditionally THC is thought of as the main cannabinoid to relieve pain, now we know CBD has analgesic properties in its own right. CBD attaches to and desensitises receptors that respond to heat, pain and inflammation. Small studies in humans suggest CBD is effective in treating peripheral neuropathic pain (nerve pain occurring outside the brain or spinal cord) which can arise from injuries, infections and conditions like diabetes.
Does CBD have side effects?
Everyone is different, but the known possible side-effects from cannabidiol (CBD) in prescribed medicinal cannabis treatments include fatigue and sedation, vertigo, nausea and vomiting, fever, decreased or increased appetite, dry mouth, and diarrhoea.
A recent self-reporting study conducted in New Zealand showed statistically significant reductions in pain, as well as improvements in mobility for non-cancer-pain patients.
Side effects of CBD were reported by 9% of individuals, mostly commonly drowsiness and vivid dreams. Much like any other pharmaceutical drug, side effects are common in patients prescribed with CBD inclusive treatments. General side effects of cannabidiol include drowsiness, gastrointestinal upset and nausea. In most clinical trials and anecdotal reports involving CBD, individuals note these side effects to be tolerable and mild, especially in light of the positive benefits they are receiving.
Medical cannabis guidance and chronic pain in Australia
When it comes to the evidence behind medical cannabis for chronic pain, the science is mixed, yet anecdotes abound. The Therapeutic Goods Administration lists chronic pain under its medical cannabis guidance documents and offers information on its evidence, recommended dosing and prescription.
Experiences with medical cannabis and chronic pain
Australian patients have shared their outcomes with prescribed medical cannabis for pain with the ABC in 2019. One patient, Beth McDougall, diagnosed with advanced lung cancer was experiencing chest pain that caused her to wake and take potent painkillers every two hours throughout the night.
Beth who never had, nor thought she would try cannabis shared that while medical cannabis hasn’t been a miracle cure, it reduced pain enough to aid her sleep and therefore improved her engagement with life. Others such as Christian Read who suffers from Multiple Sclerosis, found that medical cannabis oil has improved his sleep and pain levels, reducing his need for opioids and more generally allowing him to have a positive outlook on life.
Mental health, chronic pain and medical cannabis
For Australian patients experiencing chronic pain, the symptoms can be not only physically debilitating but also take a toll on one’s mental health. According to Pain Australia, 44.6% of chronic pain sufferers also present with mental health conditions. When pain extends past months and into years, with little aid from conventional treatments, it can be a struggle for patients to keep a positive attitude when the one constant in life is pain. In that case, patients should talk to their doctor about exploring alternative therapy options such as medical cannabis.
More research needed for medical cannabis and chronic pain
As with most aspects of the medical cannabis industry, more research is warranted. In the meantime, there is sufficient evidence supporting the use of medicinal cannabis preparations to relieve chronic pain that it is being prescribed with increasing prevalence around the world and in Australia.