Cannabis is widely used in health and wellness arenas all over the world. Across all medical cannabis (marijuana) laws in the United States, marijuana is legally recognized as a form of therapy or medicine for more than 50 qualifying conditions, including Alzheimer's disease, anorexia, arthritis, cancer, chronic pain, epilepsy, and post-traumatic stress disorder. I am going to focus on the use of cannabis for musculoskeletal problems such as arthritis, chronic pain, neuropathic pain, post-operative pain, fibromyalgia, and rheumatoid arthritis. It is also used in the treatment of muscle spasms or spasticity associated with multiple sclerosis.
The federal government still has cannabis listed as a schedule 1 drug (no accepted medical use and high risk for addiction). Therefore, it makes it difficult to do research on the drug because funding is limited. There have been inconsistencies with the strengths and percentages of the two primary compounds (cannabinoids) in cannabis in dispensaries across the nation.
There are four main cannabinoids found in cannabis. Two types of THC (THC and THCa) and two types of CBD (CBD and CBN). The THC cannabinoids are responsible for the psychoactive effects, or the “high” one feels when taken. The other two CBD cannabinoids are responsible for the anti-inflammatory, pain relieving, or the anti-anxiety properties of the drug.
Products sold have a mixture of CBD and THC. For example, ratios of CBD to THC are sold in 20:1, 18:1, 4:1 to allow for the fine tuning of these compounds to work with the many different ailments. I have a current patient, Ron (not his real name) that have tried various strengths of THC. A low dose of THC would be found in a 20:1 tincture. This has allowed him to stay away from the “high” and get the benefits of the anti-inflammatory properties for his arthritic knee joints. Ron takes his cannabis in a tincture to avoid the adverse side effects of smoking it. Taking the cannabis orally he gets the quick effects of the drug (0 – 15 minutes). I have observed many patients use marijuana over the years because patients want relief without side effects. People like the benefits of pain relief and the anti-inflammatory effects they are getting from cannabis with minimal to no THC without the side effects of their prescription anti-inflammatories. This is where it gets tricky. I recommend all my patients to talk with their primary care physician about their choice to experiment with cannabis for pain relief. Your physician will be able to tell you if it is safe for you considering your whole medical history and current medication use.
As a PT, our national and state associations do not allow us to recommend the use of cannabis for any condition. We are also prohibited from consuming any cannabinoids that have a level of THC to be > 0.4%. Therefore, for example, I can only take a product with a 20:1 ratio of CBD: THC to stay within the federal law to manage my knee arthritis. Of all the delivery methods of ingesting cannabis to the body, edibles, tinctures, capsules, and topicals are the most common I have seen in my practice. The other two, smoking and vaporizing, have substantially more side effects and the apparent problems of causing potential lung and airway pathologies from tobacco.
The Research
The FDA has approved a few drugs that contain CBD for specific diagnoses. Epidiolex is used to treat seizures as a complication to Lennox-Gastaut syndrome or Dravet syndrome in patients > 2 years old. Marinol and Syndrose (Dronabinol) are used in the treatment of anorexia associated with weight loss, and Cesamet (Nabilone) used for chemotherapy patients suffering from severe nausea and vomiting.
When I look for quality research, I find systematic reviews or meta-analyses. This is a group of researchers that have synthesized all the current research that passed the test of being a good quality study. They put them all together and discuss the overall findings. A study by Whiting (2015) Cannabinoids for medical use: A systematic review and meta-analysis had these conclusions after reviewing 79 studies. They ranked studies as moderate or low level of quality evidence. The moderate quality evidence was found in treating patients with chronic neuropathic or cancer pain and spasticity related to multiple sclerosis. The low-quality evidence was found in the treatment for nausea and vomiting due to chemotherapy, weight gain in HIV, sleep disorders, and Tourette syndrome.
Adverse Effects
It goes without saying that the most common side effect is the increase in appetite, which can lead to an increase in weight. Dry mouth and fatigue are other side effects primarily from smoking. High THC levels are known to be risk factors for mental illness, impaired memory, create paranoia, and dependency. Based on genetics, psychotic effects can vary depending on genes. Pregnancy and the use of cannabis should never be used due to the impact it has on the fetus. And lastly, no one under the age of 18 should be using cannabis for medical reasons or recreation due to the high risk of dependency and potential impaired brain development. It is still early in the area of consistent research and product. If you are suffering from pain, and hope to try an alternative plan for pain control, talk with your physician about your idea and make it a well-informed decision.