Guidance for the use of medicinal cannabis in Australia: Patient information

Disclaimer: This guidance document was developed in 2017 and reflects the research on medicinal cannabis available up to that time. Clinical guidance is not usually the role of the TGA as a therapeutic goods regulator, however, the information was developed to support medical practitioners at the time. The TGA is discussing potential avenues for updating this research in the future.

Version history

• The clinical guidance documents were developed in 2017 and provide a broad overview of the evidence available at that time to support medicinal cannabis use.
• In February 2020, the National Drug and Alcohol Research Centre reviewed the clinical evidence for the use of medicinal cannabis published in refereed medical journals since the clinical guidance documents were released. Additional relevant studies were included in the bibliographies for epilepsy and pain.
• In November 2024, the clinical guidance documents were updated to reflect current regulatory information. 

Important considerations

• Guidance documents are not the same as clinical guidelines. Guidance documents are documents produced to provide advice and further explanations and do not specify requirements that are binding in regulation.
• Healthcare practitioners are encouraged to conduct their own research to ensure their knowledge and prescribing reflects the current state of evidence of medicinal cannabis.

Further information

Visit the TGA’s medicinal cannabis consumer hub for additional information on how the TGA provides legal access to medicinal cannabis products in appropriate circumstances. 

Medicinal cannabis: patient information

Over the past few years, a number of Australians have expressed interest in the use of cannabis for medicinal purposes. The Commonwealth and State and Territory governments have either used their current laws or passed specific laws to allow the prescribing and dispensing of medicinal cannabis products. The Commonwealth, and in some cases, State and Territory governments, have also passed laws allowing cannabis cultivation and manufacture for medicinal purposes.

Currently there is limited evidence about the effectiveness of medicinal cannabis for use in different medical conditions. There is also little known about the most suitable doses of individual cannabis products

For a medicinal cannabis product to be registered in the Australian Register of Therapeutic Goods (ARTG), a sponsor (usually a pharmaceutical company) needs to submit a dossier of evidence including data on the clinical efficacy, safety and manufacturing quality to the Therapeutic Goods Administration.

There are two medicinal cannabis medicines included in the ARTG for use in Australia for specific clinical conditions: nabiximols - external site (Sativex) and cannabidiol - external site (Epidyolex). Other medicinal cannabis products available in Australia are ‘unapproved’ and may be accessed with a prescription from a healthcare practitioner. Further information about access pathways for medicinal cannabis is available on the medicinal cannabis hub.

In 2017, the Australian Government Department of Health and the NSW, Victorian and Queensland state governments commissioned a team from the Universities of New South Wales, Sydney and Queensland under the co-ordination of the National Drug and Alcohol Research Centre (NDARC) to review the available clinical evidence for using medicinal cannabis. The team focused on the five areas for which the largest numbers of studies have been carried out - palliative care, chemotherapy-induced nausea and vomiting, chronic pain, multiple sclerosis and epilepsy in paediatric and adult patients.

The researchers conducted a review of previously published reviews from multiple databases. Searches were guided by a specialist Librarian using specific search terms and were limited to studies published between 1980 and early 2017. Two reviewers independently examined titles and abstracts for relevance and the GRADE (grading of recommendations, assessment, development and evaluation) approach to evaluating the quality of evidence was applied. The GRADE^[1] method is the international standard that applies to weighting of evidence in scientific and medical literature and gives weight to certain evidence based on the level of evidence and strength of recommendation. For example, evidence as a result of randomised control trials (RCTs) are given priority because this study method typically yields more reliable results. RCTs are at the top of the hierarchy of evidence.

This guidance provides a broad overview of the evidence (up to December 2017) to support using medicinal cannabis for the above conditions. It also highlights the cautions surrounding treatment, how medicinal cannabis can be prescribed and future research.

The evidence

Doctors rely on evidence to make informed decisions about the best medications for their patients. For medicinal cannabis, the amount of evidence is currently limited and the products, doses and research methods used vary between studies. This makes it difficult to come to firm conclusions about how best to use particular medicinal cannabis products.

There is also not much information available to help doctors determine the most appropriate and safe doses while minimising potential side-effects. Importantly, at the moment, relatively few studies compare the effects of medicinal cannabis products against currently approved treatments for various conditions and symptoms. In addition, most of the studies reported in the medical literature have either used purified pharmaceutical substances or smoked cannabis.

As there is limited scientific evidence to support the use of medicinal cannabis in most conditions, and in many cases the evidence is for its use together with other medicines, it should be used only when approved treatments have been tried and have failed to manage conditions and symptoms.

Access to medicinal cannabis

Medicinal cannabis can only be prescribed by a registered medical practitioner.

Information about accessing medicinal cannabis as an 'unapproved' medicine is available on the medicinal cannabis hub.

The products

This information is intended to assist prescribers of medicinal cannabis with product selection. It is not intended to be a product guide for patients. Patients should seek advice on the product that is most appropriate for their circumstances from their doctor or nurse practitioner.

A variety of Australian and imported products are available. These include raw (botanical) cannabis, which for medicinal purposes should be vaporised but not smoked, cannabis extracts in oils, capsules, suppositories, pastilles and solvent extracts such as tinctures, and oro-mucosal sprays. Some products for trans-dermal application (patches or topical application of gel or cream) have also been developed.

A challenge to note is that many of the studies described in the medical literature have used either illicit smoked cannabis (which is not recommended on health grounds) or purified synthetic tetrahydrocannabinol (THC) or cannabidiol (CBD), rather than many of the types of whole plant products that are currently available.

There are up to 100 cannabinoids in the cannabis plant. The cannabinoids are most abundant in the female flower head, which is used in the manufacture of medicinal cannabis products.

Tetrahydrocannabinol (THC) is responsible for the psychotropic effects of cannabis and is the reason cannabis is used recreationally. 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.

A second cannabinoid, cannabidiol (CBD) is not psychotropic and may be useful in the management of seizures, pain, and may have anxiolytic and antipsychotic effects. 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). Other cannabinoids under active research include cannabigerol (CBG), tetrahydrocannabivarin (THCV), cannabinol (CBN) and cannabichromene (CBC). The cannabis plant also contains terpenes which give cannabis its flavour and aroma. It is unclear whether terpenes have their own pharmacological effects.

Medicinal cannabis and epilepsy in paediatric and adult patients

There is some evidence to support using medicinal cannabis in the treatment of certain childhood epilepsies

Epidyolex (cannabidiol) was approved by the TGA in September 2020 for use as adjunctive therapy of seizures associated with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) for patients 2 years of age and older.

On 1 May 2021, Epidyolex was listed on the Pharmaceutical Benefits Scheme (PBS) for Dravet syndrome.

The main purpose of epilepsy medications is to reduce the number of seizures and ideally to stop them altogether. There is some evidence to support using medicinal cannabis in the treatment of certain childhood epilepsies.

Cannabidiol (CBD) is the substance featured in most published evidence on medicinal cannabis as an epilepsy treatment. However, this evidence is when it is used as an add-on to current treatments in drug-resistant epilepsy in children and young adults up to 25 years where use of several anti-epileptic drugs has not controlled their condition. In patients with paediatric-onset drug-resistant epilepsy, CBD products reduced seizure frequency by 50 per cent or more in up to half of the patients and achieved seizure freedom in a small number of patients. Several studies have reported improved quality of life in paediatric and adult groups, but overall there are few studies of how effective CBD is in treating adult epilepsy. There is not enough evidence to recommend this treatment for adults.

There is no evidence to support medicinal cannabis as a rescue therapy for status epilepticus (a single seizure lasting more than five minutes or two or more seizures within a five-minute period without the person returning to normal between episodes).

Information is limited on the most effective starting doses to treat epilepsy in children and young adults. As extra care is needed, it is expected that paediatric neurologists would be involved in the management of these children.

Medicinal cannabis and multiple sclerosis (MS)

There is some low to moderate evidence to suggest that medicinal cannabis products may be effective for treating the pain symptoms of MS

There is a TGA registered medicine (Nabiximols, which are an extract of cannabis plant containing roughly equal amounts of THC and CBD) for the use in MS for muscle spasticity. Five of ten studies carried out on other cannabinoids concluded that there was evidence that cannabinoids may be effective for symptoms of pain and/or spasticity and positive effects on sleep and bladder symptoms. It should be noted that the other five studies were inconclusive or did not show that treatment with cannabinoids had any positive effect in MS.

There is some low to moderate evidence to suggest that medicinal cannabis products may be effective for treating the pain symptoms of MS, although this is inconsistent. Studies differ as to whether medicinal cannabis products can help improve bladder function, sleep, quality of life, ataxia/tremor and disability/disease progression.

There are also currently no studies that compare medicinal cannabis products to the most effective and commonly used medications for MS pain and spasticity. Therefore, there is no evidence to support the use of most cannabinoids as a single, primary or initial treatment.

Treating doctors should assess people with MS after 12 weeks to re-evaluate and monitor both the positive and negative effects of the drug.

Treating chronic non-cancer pain

There is some evidence that cannabinoids can reduce pain in both MS-related neuropathic pain and non-MS-related neuropathic pain, but for many people the reduction in pain may be modest. There is, however, insufficient information to make a conclusion about cannabinoids for the treatment of pain associated with arthritis and fibromyalgia

The majority of the studies on the use of cannabinoids in pain have studied THC or THC-rich extracts. The studies are mainly where cannabinoids were "adjuvant" treatments, used in addition to other pain medicines.

Most studies have been on chronic (long-term) rather than acute (short-term) pain. Patients and healthcare professionals recognise that there are two main types of chronic pain. Nociceptive pain, which can be found with or without cancer, is caused by damage to body tissue and usually described as a sharp, aching, or throbbing pain to the bones, muscles, or joints, or that causes the blockage of an organ or blood vessels. Neuropathic pain occurs when there is nerve damage, in particular to those nerves in the spinal cord. The pain is often described as a burning or heavy sensation, or numbness along the path of the affected nerve.

There is some evidence that cannabinoids can reduce pain in both MS related neuropathic pain and non-MS related neuropathic pain, but for many people the reduction in pain may be modest. There is, however, insufficient information to make a conclusion about cannabinoids for the treatment of pain associated with arthritis and fibromyalgia.

Current studies show no evidence that medicinal cannabis can improve overall quality of life or physical functioning. There is also some evidence that it can improve sleep.

There is much interest at present as to whether cannabinoids are "opioid sparing" – in other words, whether use of medicinal cannabis products for pain can result in a reduction of use of strong opioids. If this were the case, deaths and incapacity from opioid overdoses could be reduced, given that cannabinoids have fewer adverse outcomes. While some individuals with pain have reported that their use of opioids has been reduced when they also use medicinal cannabis, clinical studies in this area are still ongoing.

Preventing and managing chemotherapy-induced nausea and vomiting in cancer (CINV)

There are some reports that medicinal cannabis products (in particular THC and related substances) relieved the symptoms of CINV. However, the number of studies is small, and the quality of published evidence is low to moderate. While several studies found that the medicinal cannabis products were as effective as the prescription medicine it was compared with, most of the research studies were carried out some years ago, and in recent years much more effective prescription medicines for nausea and vomiting have become available.

For these reasons, THC-rich medicinal cannabis products for chemotherapy induced nausea and vomiting should be prescribed only after standard approved treatments have failed.

Medicinal cannabis use in palliative care

There is no evidence at this time that medicinal cannabis has any anti-cancer activity or that it can slow the progression of these conditions

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. The published studies in the medical literature showed little effect on appetite, nausea/vomiting, pain, dizziness, mental health or sleep problems. There is also no evidence that medicinal cannabis has any anti-cancer activity in human studies or that it can slow the progression of these conditions.

In people without acquired immunodeficiency syndrome (AIDS), there is also no evidence that medicinal cannabis will increase their appetite, that it will help the patient gain weight or that it will enhance their mood.

It is important to note that some side-effects from medicinal cannabis treatment may be similar to symptoms of distress often experienced by people in end-of-life care.

As there are very few studies on medicinal cannabis treatment in palliative care, it should be used only after standard treatments have failed. It is possible that medicinal cannabis will interact with chemotherapy and other medications used in palliative care. More studies are needed to better understand this.

People with life-limiting conditions may want to enrol in clinical trials to help increase the amount and quality of evidence to support or contradict medicinal cannabis use in this setting.

Summary of evidence by condition

The side effects of medicinal cannabis treatment

Like all prescription medicines, medicinal cannabis products can have side effects. The extent of effects of these can vary with the type of medicinal cannabis product and between individuals. In general, the side effects of CBD-rich products are less than those for high-THC products, but because the required doses for CBD can be quite high in conditions such as paediatric epilepsies, a proportion of patients encounter side-effects with these CBD doses.

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).

General cautions

• Patients should not drive or operate machinery while being treated with medicinal cannabis. In addition, measurable concentrations of THC (tetrahydrocannabinol – the main psychoactive substance in cannabis) can be detected in urine many days after the last dose. It may take up to five days for 80 to 90 per cent of the dose to be excreted. Drug-driving is a criminal offence, and patients should discuss the implications for safe and legal driving with their doctor.
• Medicinal cannabis is not appropriate for:
  • people with an active or previous psychotic or active mood or anxiety disorder
  • women who are pregnant, planning to become pregnant or breastfeeding
  • people with unstable cardiovascular disease.
• Patients with neurological conditions may be more likely to experience negative effects from medicinal cannabis.
• There is no information available on the most effective or safe dose for various conditions and symptoms. For this reason, starting doses should be low and increased over time until patients respond positively or the negative effects outweigh the perceived benefits. Low start doses are particularly important for people with memory and thinking difficulties, liver and kidney disease, and weakness and wasting of the body due to severe chronic illness. Low start doses are also important for young people and the elderly.
• Doctors should:
  • carefully assess elderly and particularly sensitive patients
  • regularly monitor interactions between medicinal cannabis and other treatments
  • assess liver function when deciding to continue or stop treatment.
• Although there may be some evidence to suggest a benefit from medicinal cannabis treatment for one condition or symptom, this does not mean it will have benefits for other conditions, even with the same product and the same dose.

There is very limited evidence to show how medicinal cannabis reacts with other approved medications.

To report a problem or a side-effect with a medicine to the TGA, visit: Report a problem or side effect.

More research is needed

There is a significant need for larger, high-quality studies to better explore the potential benefits, limitations and safety issues associated with medicinal cannabis treatment across a range of health conditions and symptoms.

More research will:

• increase the amount and quality of evidence to either support or contradict the use of medicinal cannabis as an approved treatment
• give a more detailed understanding of the most effective cannabis products, doses and administration methods for treating various conditions
• compare medicinal cannabis with standard first line medication options currently used to treat various conditions
• build a strong knowledge base on how medicinal cannabis interacts with other drug treatments.

Prescribing doctors should also collect data based on first-hand patient experience. This will further inform our knowledge and understanding of how to use medicinal cannabis effectively and safely.