Medical cannabis is cannabis and cannabinoids that are prescribed by your doctor for various illnesses. The history of cannabis for medical purposes dates back to ancient times and is believed that China was among the first countries to use it as medicine. As cannabis is the most common trafficked and abused illicit drug worldwide its use in medicine has not been thoroughly researched yet for its safety and efficacy due to various restrictions worldwide.
In recent years however therapy with medical marijuana has garnered much attention for positive reasons worldwide. The use of cannabis for medical purposes is on the up and there are currently 42 countries that have legalized the use of medical cannabis. In addition to these countries, some countries have legalized the use of only certain cannabis-derived medicines. 35 states and the District of Columbia in the United States have legalized its medical use. Despite the growing use of cannabis for medical purposes, there are still more than 100 countries where its use is prohibited.
Medical Uses of CannabisYou can use medicinal cannabis in different forms including capsules, sprays, vapors, or through smoking dried flowers of cannabis. Though much needs to be learned about the safety and efficacy of cannabis for medical purposes, evidence has shown it to be somewhat effective in:
- Alleviating Chronic Pain: Chronic pain following different medical conditions is associated with long term disability. The use of medical cannabis is observed to be an effective alternative in managing chronic pain. Peripheral nerves in your body that detect pain have shown to have multiple cannabis receptors; cannabinoids are shown to reduce pain by modulating these receptors. Also, chronic pain in cancer caused due to nerve damage, inflammation, and invasion of sensitive structures in your body is also said to be reduced by the use of cannabis.
- Chemotherapy-induced nausea and vomiting: Cannabinoids have been shown to improve nausea and vomiting caused by chemotherapy in cancer patients. Though the exact mechanism is not known it is thought to be caused by blocking certain receptors that trigger vomiting.
- Parkinson’s disease: Significant amounts of cannabinoid receptors are found to be present in part of your brain called the basal ganglia and there is increasing evidence that suggests it has a modulatory function in the basal ganglia. Parkinson’s disease is caused by a defect in nerve cells of basal ganglia The use of medical cannabis has been observed to improve slow movement (bradykinesia), rigidity, and tremor, increase sleep, and alleviate pain in Parkinson’s disease.
- Glaucoma: Glaucoma is a condition of your eye where increased pressure leads to optic nerve damage. The use of cannabis has been shown to reduce the pressure in your eyes thus improving the condition and staking its claim as a viable alternative to traditional methods of treatment.
- Post-Traumatic stress disorder: Studies have shown cannabis to reduce activity in the amygdala- the part of the brain that controls response to fear and threat thus reducing past trauma-related anxiety in these patients.
- Inflammatory Bowel Disorder: Some evidence have shown cannabis and cannabinoids to improve symptoms in these disorders by reducing inflammation through its receptors present in the GI tract (tract for food passage)
- Multiple Sclerosis: It is a disorder where your immune system acts against myelin sheath which covers your central nervous system producing various symptoms. Spasticity (stiffness) caused by multiple sclerosis is thought to be improved by the use of cannabinoids.
- Anorexia: Medical cannabis used in conjunction with cognitive behavioral therapy has shown to improve anorexia. This is because active ingredients of cannabis have appetite-stimulating properties.
The current knowledge on medical cannabis use suggests that it is an appropriate alternative therapy option for patients who have chronic pain, multiple seizure episodes, and movement disorders. Further study is required to understand its exact use in improving GI disorders, managing patients with MS, anorexia, and headache. Caution should be taken while prescribing cannabis products.
Clinical TrialsVarious trials are underway to assess the efficacy and safety of medical cannabis, as this is a field with limited knowledge yet having vast potential.
- A study is being carried out to see how they use medical cannabis (using a soft gel form) affects opioid analgesic effects in treating chronic pain as well as the associated adverse effects. This study also helps assess if cannabis can be suitable replacement therapy instead of opioids.
- Children with CNS tumors are being observed for their quality of life following treatment with medical cannabis. Through this study, the researchers will also evaluate immune-modulation caused by cannabis in immunocompromised patients by collecting blood samples from them.
- A study on the effects of cannabis in treating neuropathic pain caused in HIV patients is also being studied and it is in the second phase of its trial. Along with the efficacy, the consequences of long-term chronic use of cannabis and the relationship between HIV pain and cannabis will also be assessed through this study.
- Multiple new therapies and prevention strategies are being tested to combat the current COVID-19 pandemic. An online questionnaire model has been developed to assess the effectiveness of medical cannabinoids in the prevention and treatment of COVID-19. It will be compared to other methods in preventing and treating the disease.
- The role of cannabis and cannabinoid agonist dronabinol given in low doses as an adjunct to antipsychotic medication is being studied for its effect in improving schizophrenia by ameliorating brain reward circuit dysregulation.
- The pain healing mechanism of medical marijuana is being tested for providing effective relief from chronic neck and back pain by comparing its functions with Oxycodone and placebo. This study is currently in Phase 3 of its trial.
- The effectiveness of low dose Cannabis and its metabolites in treating drug-resistant cases of epilepsy is also being studied. Cannabis is thought to reduce the incidence of seizures in these patients.
- A multistate, multicenter clinical study which is under Phase 2 of trial which includes the assessment of safety and efficacy of cannabis in treating multiple medical conditions including:
- Chronic Pain Syndrome
- Hepatitis C
- Crohn Disease
- Multiple Sclerosis
- Traumatic Brain Injury
- Sickle Cell Disease
- Post- Traumatic Stress Disorder
- Tourette Syndrome
- Ulcerative Colitis
- Inflammatory Bowel Diseases
- Parkinson Disease
- Amyotrophic Lateral Sclerosis
- Chronic Traumatic Encephalopathy
- Opioid-use Disorder
- Bipolar Disorder
Yara Mouhamed et al. Therapeutic potential of medicinal marijuana: an educational primer for health care professionals. Drug Healthc Patient Saf. 2018; 10: 45–66. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6001746/)
Misty Pratt et al. Benefits and harms of medical cannabis: a scoping review of systematic reviews. Syst Rev. 2019; 8: 320.( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6905063/)
Mary Barna Bridgeman, Daniel T. Abazia et al. Medicinal Cannabis: History, Pharmacology, And Implications for the Acute Care Setting. P T. 2017 Mar; 42(3): 180–188.( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5312634/)