Our position on the use of Medical Marijuana and Medicinal Cannabis in Parkinson’s
There are many endorsements of cannabinoids for Parkinson’s symptoms in the social media. However, the science tells a different story.
Statement of Position
Further research into the efficacy and safety of medicinal cannabis in the treatment of symptoms in Parkinson’s disease is necessary before Fight Parkinson’s will advocate its use for people with Parkinson’s disease.
Medicinal Use of Cannabis
The two main active ingredients used for medical care are tetrahydrocannabinoids or THC and cannabidiol or CBD. Both are referred to as cannabinoids. THC is the part that produces the ‘high’ favoured by recreational users of cannabis and may have benefits in reducing nausea. CBD produces no ‘high’and may be used to treat pain inflammatory conditions and seizures. Generally, the use of either form of medicinal cannabis is for symptom relief and is not a ‘cure’.
The Evidence Base for Medicinal Cannabis
Many people with a range of serious conditions such as cancer have reported symptom benefits from cannabis or medical marijuana. A review of current scientific research suggested there was reasonable evidence that cannabinoids can help symptoms of chronic pain and spasticity including that experienced in Multiple Sclerosis. In other conditions, such as in nausea and vomiting due to chemotherapy, weight gain in HIV infection, sleep disorders, and Tourette syndrome use of cannabinoids remains unproven.
There are many endorsements of cannabinoids for Parkinson’s symptoms in the social media. However, the science tells a different story.
In the case of Parkinson’s, there are concerns that taking marijuana may cause confusion or in some cases lead to psychotic symptoms. Also, the evidence to date that cannabinoids can reduce symptoms of Parkinson’s disease is extremely low. This does not mean that cannabis has no benefits for people with Parkinson’s; it may well be related to the standards of the research conducted. Most of the studies conducted on cannabis in Parkinson’s have been via self-report surveys, case studies, observational studies and four small, short term randomised placebo-controlled trials. Most of these studies are limited due to the very small numbers of participants, or lacked data on the consistency and quality of the cannabis products. Five of the ten studies reported some benefits, but most studies were too short term or too small to record any adverse events or harms. Most studies considered that far more research using randomised double-blind placebo-based trial methodologies is necessary (Stampononi Bassie et al). Stampononi Bassi et al note that: “Results from available clinical studies are controversial and inconclusive due to severe limitations, including small sample size, lack of standardised outcome measures, and expectancy bias”.
The US-based Committee on the Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research reviewed current evidence and concluded that “There is insufficient evidence that cannabinoids are an effective treatment for the motor system symptoms associated with Parkinson’s disease or the levodopa-induced dyskinesia.” (National Academies of Science 2016)
Changing Legal Framework
The Access to Medicinal Cannabis Act 2016 was passed by the Victorian Parliament in April 2016. Children with intractable epilepsy were the first to be given access to an imported CBD product. At the same time the Act also made way for the establishment of a medicinal cannabis industry to produce consistent, high quality products for medicinal use. This was followed by changes in regulations in NSW to allow medical practitioners to prescribe medicinal cannabis in a range of conditions including cancer, MS, arthritis and anxiety and depression. More recently Queensland Parliament passed legislation to make medicinal cannabis available to certain groups of patients who have exhausted other treatments through prescriptions.
Currently, Parkinson’s disease is not included by any of the States’ lists of conditions where medicinal cannabis is considered to have benefits. This does not mean that access is completely banned. An individual with Parkinson’s in some States can approach a medical practitioner and request it if they consider that all other options have been exhausted. Fight Parkinson’s recommends that individuals should fully explore all their options and be fully informed of any side effects and costs beforehand.
All legislation underlines that the unregulated use of cannabis products remains illegal and that the legislation does not equate to the decriminalisation of marijuana for recreational use or for the personal use of marijuana for self-treatment purposes.
Prescribing of Medicinal Cannabis
Much has been put in place by the Therapeutic Goods Administration (TGA) to provide the basis for prescribing medicinal cannabis. Medicinal cannabis is imported at the moment but is regulated by the TGA. Patients will need a prescription from the treating doctor to obtain medicinal cannabis. This will come under the Special Access Scheme (SAS). If the prescribed medicine is more than 2% THC (the part of cannabis that creates a “high”) then it is considered very restricted and the doctor needs to apply for an additional Schedule 8 permit. CBD that contains 2% or less THC and is then a Schedule 4 drug and does not require anything more than the SAS permit.
Driving Motor Vehicles and Use of Cannabis Products
Driving while impaired by any drug, prescribed or not, is an offence.
Prescribed CBD is not an illicit drug under the Road Safety Act in Victoria. However, CBD would be considered a drug by the Road Safety Act if it deprives the person consuming it of any of his/her mental or physical capacities.
Prescribed THC is an illicit drug for the purposes of the Road Safety Act and any presence of THC in blood is a driving offence.
When being prescribed a medicinal cannabis product it is important to use it in accordance with the prescribing doctor’s directions and to seek advice as to driving a motor vehicle while using that specific product.
Summary of the Position of Fight Parkinson’s
The renewed interest in the potential for Cannabis or its extracts to provide some symptom benefit in Parkinson’s disease is encouraging.
Fight Parkinson’s in collaboration with leading neurologists and the Chronic Illness Alliance has evaluated the small number of randomised controlled trials, and noted that the studies were too small and found inconsistencies and a lack of information on safety and efficacy of the cannabis products. Fight Parkinson’s concludes that there is a lack of evidence about the benefits and safety of medicinal cannabis products in treating symptoms of Parkinson’s disease.
Fight Parkinson’s is supportive of appropriate ethically approved scientific research into the therapeutic benefits of medicinal cannabis. In the face of limited evidence we recommend that individuals who wish to access medicinal cannabis fully inform themselves of any benefits, risks and costs, discuss these with a medical practitioner and also explore any other treatment options.
For further information, please Contact Us.
References
Kluger B, Triolo P, Jones W, Jankovic J. The Therapeutic Potential of Cannabinoids for Movement disorders, Movement Disorders Vol 30 No 3, 2015
Carroll CB, Bain PG, Teare BM, Lui X, Joint C, Wroath BA, Parkin SG, Fox P, Wright D, Hobart J, Zajicek JP, Cannabis for dyskinesia in Parkinson Disease. Neurology October 2004
Stampanoni Bassi M,Sancesario A, Moreace R, Centonze D, Iezzi E Cannabinoids in Parkinson’s Disease Cannabis and Cannabinoid Research Vol 2.1 2017