Medicinal cannabis: patient information
The prescribing and dispensing of medicinal cannabis products under specific circumstances is now legal in Australia.
The cultivation and manufacture of medicinal cannabis products have also been legalised by the Commonwealth, and in some cases, State and Territory governments.
What is medicinal marijuana?
The term medicinal marijuana refers to treating a disease or its symptoms with the whole unprocessed marijuana plant or its basic extracts.
There are more than 545 chemical compounds in marijuana; 104 of them are cannabinoids, which are the active ingredients in cannabis (cannabis is how marijuana is referred to when it is in plant form).
The ingredients in different plants and species vary.
The two cannabinoids that have been studied are delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD), and different cannabis strains contain different ratios of THC to CBD.
It is unclear whether THC and CBD act individually or synergistically (in conjunction with each other).
THC is probably best known for being the psychoactive ingredient in marijuana which creates the feeling of being 'high'.
THC may also be responsible for some of the medicinal effects of cannabis such as reduction of nausea, vomiting, pain and muscle spasms as well as improvements in sleep and appetite.
CBD is non-psychoactive and therefore, cannot make you high.
While disappointing to recreational users, this unique feature of CBD is what makes it so appealing as a medicine.
Evidence suggests it may be useful in the management of seizures and pain.
It may also have antipsychotic effects.
Medicinal cannabis products (with the exception of nabiximols) are not registered on the Australian Register of Therapeutic Goods (ARTG) and are not available as registered prescription medicines.
The Australian Government does not subsidise the cost of medicinal cannabis products through the Pharmaceutical Benefits Scheme (PBS) at this time.
Products similar to those available through import from Canada and Europe are being manufactured from locally grown medicinal cannabis and are expected to become available in Australia during 2018.
Until more scientific evidence is available, medicinal cannabis should be used only when approved treatments have been tried and failed to manage conditions and symptoms.
There is no evidence that medicinal cannabis has any anti-cancer activity in human studies or that it can slow the progression of these conditions.
The products will be available for use in bowel cancer patients for the prevention and management of chemotherapy-induced nausea and vomiting (CINV), and in palliative care, but only after standard treatments have failed.
While medicinal cannabis products can be used to treat nausea and vomiting due to chemotherapy, there is little evidence of any benefit to advanced cancer patients with chronic pain.
As there are few studies on medicinal cannabis treatment in palliative care, it is possible that it will interact with chemotherapy and other medications used in palliative care.
It should be used only after standard treatments have failed.
(For a full list of indications, please see the Guidance for the use of medicinal cannabis in Australia Patient information booklet, published by the Australian Government Department of Health.)
Like all prescription medicines, medicinal cannabis products can have side effects.
Side effects vary and depend on the medicinal cannabis product type used and the patient being treated.
The known side-effects from medicinal cannabis treatment (both CBD and THC) include fatigue and sedation, vertigo, nausea and vomiting, fever, decreased or increased appetite, dry mouth, and diarrhoea.
THC (and products high in THC) have been associated with convulsions, feeling high or feeling dissatisfied, depression, confusion, hallucinations, paranoid delusions, psychosis, and cognitive distortion (having thoughts that are not true).
Medicinal cannabis products can only be prescribed by a registered medical practitioner.
With the exception of nabiximols, medicinal cannabis products are not registered medicines in Australia, so they must be accessed through special pathways available for unapproved medicines.
The above information has been drawn directly from the Guidance for the use of medicinal cannabis in Australia Patient information booklet, published by the Australian Government Department of Health.
The Department of Health will update the brochure as new evidence emerges.