Last published: July 30, 2019
Note: The information given on this page is not medical advice and should not be relied on in this way. Individuals wanting medical advice on this issue should consult a health professional.
What is medicinal cannabis?
Broadly speaking, medicinal cannabis is cannabis prescribed to relieve the symptoms of a medical condition, such as epilepsy. It is important to make the distinction between medicinal cannabis and recreational cannabis. Recreational cannabis is the form of cannabis that people use to get ‘high’.1
For some people suffering from chronic or terminal illnesses, conventional medicines do not work, or do not work as effectively as medicinal cannabis. Also, for some patients, conventional medicines may work but cause debilitating side effects that cannabis can help to relieve.2
What are cannabinoids?
The main psychoactive ingredient of cannabis is tetrahydrocannabinol (THC), which acts on specific receptors in the brain known as cannabinoid or CB1 receptors.3
Research has found that the cannabis plant produces between 80 and 100 cannabinoids and about 300 non-cannabinoid chemicals. The two main cannabinoids that have been found to have therapeutic benefits are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). There have been claims that a number of other cannabinoids have therapeutic properties, but these have not yet been proven.1
The main difference between the two cannabinoids is that THC has strong psychoactive effects, meaning it makes a person ‘high’, whereas CBD is thought to have an anti-psychoactive effect that controls or moderates the ‘high’ caused by the THC. CBD is also thought to reduce some of the other negative effects that people can experience from THC, such as anxiety.4
The psychoactive effects of THC, such as euphoria and feeling relaxed or sleepy, are well known, but THC has also been found to have analgesic, anti-inflammatory and antioxidant properties, as well as being able to prevent and reduce vomiting.1
Research is being conducted into CBD for its potential to treat epilepsy, schizophrenia and other psychotic disorders, type 2 diabetes, inflammatory bowel disease, some tumours, and drug dependency.1
The endocannabinoid system
The endocannabinoid system is a unique communications system found in the brain and body that affects many important functions.5 It is made up of natural molecules known as cannabinoids, and the pathways they interact with. Together, these parts work to regulate a number of activities, including mood, memory, sleep and appetite. It is thought that medicinal cannabis can treat various illness by acting on the endocannabinoid system.6
Types and forms of medicinal cannabis
There are three main forms of cannabis that can be used medicinally:
- Pharmaceutical cannabis products that are approved by an organisation such as the Therapeutic Goods Administration (TGA), including nabiximols (Sativex®) and synthetic cannabinoids such as Dronabinol®. Sativex, which comes as a nasal or oral spray, has been approved in over 24 countries for treating spasticity due to multiple sclerosis.
- Controlled and standardised herbal cannabis (plant products), such as the products produced in the Netherlands.
- Unregulated and illegal herbal cannabis (plant products), which contains unknown concentrations of cannabinoids and potentially harmful impurities such as bacteria and mould (USA only).7
Why smoking cannabis for medical purposes is not recommended
A number of people make the claim that smoked cannabis should be considered as a treatment for various medical conditions or even as a cure for cancer. However, there are two major concerns regarding this type of cannabis and this method of administration. Firstly, smoking is a particularly harmful way of taking cannabis, mainly because carcinogenic substances are inhaled directly into the lungs. Smoking cannabis is not recommended by health authorities, as the smoked form contains at least 50 of the same carcinogens as tobacco.8
Secondly, the majority of medicines used in Australia are produced under strict conditions: that way, doctors who are prescribing them (as well as people who are using them) know exactly what is in them. It is important that doctors know that medicines have been tested and that each dose is the same. This means doctors can monitor the effects of the drug and doses can be adjusted according to a patient’s needs. When recreational cannabis is used as medicine, doctors and patients can’t be sure of these things – they don’t know how strong it is or what mix of chemicals is in it, and as a consequence, one dose will never be the same as another.8
It is understood that smoked cannabis will not be prescribed in Australia because smoked plant products will not satisfy governmental requirements that enable it to be classed as a therapeutic good.9
There is a considerable need for medicines and therapies that can help and alleviate the painful symptoms of a number of illnesses and diseases. An increasing number of studies suggest that medicinal cannabis in the form of oral extracts, sprays or pills can reduce these symptoms and aid in the treatment of some illnesses. However, as with many other drugs, medicinal cannabis can also cause unwanted side effects, such as difficulty with concentration, dizziness, drowsiness, loss of balance, and problems with thinking and memory.10
Special Access Scheme
Under the TGA Special Access Scheme, some forms of medicinal cannabis are currently available. The scheme provides for the import and supply of an unapproved therapeutic good to individual patients on a case-by-case basis. Recently, the TGA has made changes to its Special Access Scheme that will make it easier for medical practitioners to prescribe cannabis-based medicines for patients in need, under certain conditions.
Legislation to allow for the cultivation of cannabis in Australia for medical or scientific purposes has been passed by the federal government. This involved an amendment to the Narcotics Drugs Act 1967 and will allow for cultivation through a national licensing scheme.
The Narcotic Drug Amendment Bill 2016 provides a legislative framework that will permit cannabis cultivation in Australia for medicinal and related research purposes. The legislation also ensures that when the cultivation, production and manufacture of cannabis begin, Australia will remain compliant with its international obligations.
The Commonwealth will control all regulatory aspects of the cultivation of cannabis for medicinal purposes through one national scheme. Manufacture will be a joint responsibility between the Commonwealth and the states and territories. Access to any cannabis products manufactured under the scheme will also be a joint responsibility, with supply being controlled by provisions under the Therapeutic Goods Act 1989 working in tandem with state and territory drugs and poisons legislation.11,12
The Office of Medicinal Cannabis has been established within the Department of Health and Human Services and is responsible for establishing the Victorian medicinal cannabis framework. The office will work closely with the medical profession as well as patients and families as the scheme is implemented.
The NSW Government has established the Centre for Medicinal Cannabis Research and Innovation to further the understanding of cannabis and cannabis products for therapeutic purposes, and support evidence-based innovation.
The Centre will draw on local and international researchers to advance the formal understanding of medicinal cannabis, monitor the NSW-funded clinical trials, educate the community and help stakeholders navigate regulatory processes.
Queensland is making the use of approved medicinal cannabis products possible as a treatment for certain conditions when the patient has already tried the conventional treatments available for their condition or symptoms, and these have failed or cause intolerable side-effects.
Since November 2016, medical practitioners in South Australia can legally prescribe medicinal cannabis products with Commonwealth and relevant state approvals.
From 1 November 2016 it will be legal for a doctor to prescribe, and a pharmacist to dispense, medicinal cannabis in Western Australia. Despite this change in legislation, supplies of medicinal cannabis are not expected to be available until early 2017 at the earliest.
The Hodgman Liberal Government is supporting Tasmanians to get access to medical cannabis through the Controlled Access Scheme from September 1.
In order to prescribe cannabis as a controlled medicine, doctors should obtain authority from the ACT Chief Health Officer (CHO) under the same process which currently applies for other controlled medicines such as opiates and amphetamines.
A patient living in the Northern Territory must access medicines containing cannabinoids through a Northern Territory doctor who is authorised under the Special Access or Authorised Prescriber Schemes administered by the Therapeutic Goods Administration.
- Victorian Law Reform Commission (2015). Medicinal Cannabis. Retrieved from the Victorian Law Reform Commission.
- Rattenbury, S. (2014). ACT Greens Medicinal Cannabis Discussion Paper.
- Hall, W. (2015). US policy responses to calls for the medical use of cannabis. Journal of Biology and Medicine 88: 257-264.
- Mechoulam R. Cannabis—a valuable drug that deserves better treatment. InMayo Clinic Proceedings 2012 Feb 1 (Vol. 87, No. 2, pp. 107-109). Elsevier.
- NSW Parliament. (2000) Report of the Working Party on the Use of Cannabis for Medical Purposes. Sydney: NSW Parliament.
- Scholastic. (2011). The science of the endocannabinoid system: how THC affects the brain and the body.
- Belackova V, Ritter A, Shanahan M, Chalmers J, Hughes C, Barratt M & Lancaster K. (2015). Medicinal cannabis in Australia: framing the regulatory options.
- American Lung Association; Marijuana and Lung Health. [Chicago, United States]: [updated 2015 March 23; cited 2019 March 15].Callaghan, R. C., Allebeck, P., Sidorchuk, A. (2013) Marijuana use and risk of lung cancer: a 40-year cohort study. Cancer Causes Control, 24, 1811–1820.Schwartz, D.A. Int J Ment Health Addiction (2018) 16: 797.
- Therapeutic Goods Administration; Medicinal cannabis – guidance documents. 2018 May 29
- Therapeutic Goods Administration. (2018). Guidance for the use of medicinal cannabis in Australia: Patient information: The side effects of medicinal cannabis treatment
- Health Department, Australian Government. (2016). Narcotic Drug Amendment Bill 2016 public information paper.
- Parliament of Australia. (2016). Narcotic Drugs Amendment Bill 2016.