National evidence review
The Commonwealth Department of Health through the Therapeutic Goods Administration (TGA), and with the support of the NSW, Victorian and Queensland state governments, commissioned a team to review the available scientific evidence for the use of cannabis medicines in five areas. Under the coordination of the National Drug and Alcohol Research Centre (NDARC) this included research experts from the University of NSW, the University of Sydney and the University of Queensland.
The NSW Government supported the review to provide a source of credible information about the available evidence to support medical practitioners considering the use of a cannabis medicine for their patient. All medicines have potential benefits and harms and can interact with other medicines. Doctors rely on evidence to discuss treatment options with patients and to make informed decisions.
The review included the use of cannabis medicines in the management of symptoms in epilepsy, multiple sclerosis, nausea and vomiting, palliative care and pain. Advice from the review concluded:
“Currently there is only 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.”
With one exception, cannabis medicines currently available in Australia are not registered on the Australian Register of Therapeutic Goods (ARTG). Detailed evidence about the efficacy, safety and quality of a product is required for registration.
To protect patient safety, unregistered medicines, including cannabis medicines, require approval for use.
Unregistered medicines, including cannabis medicines, can be prescribed. However, because of limited evidence, it is expected that treatment with approved registered medicines have been tried first and that, based on the available evidence, the balance of expected benefits and risks favours treatment with the unregistered medicine.
Research is underway to improve our knowledge about the effects of different cannabis formulations, the best dose and route of administration, and monitoring for adverse effects and drug interactions. As evidence emerges from clinical trials and other studies, advice from the review will be updated.
A summary of the review for consumers has been developed, which can be found here.
Guidance for medical practitioners
Advice developed for medical practitioners includes an overview of cannabis medicines, available here, and guidance in relation to epilepsy (available here), multiple sclerosis (available here), nausea and vomiting (available here), palliative care (available here) and pain (available here).
Practitioners interested in using the guidance as part of an application to prescribe a cannabis medicine should review the criteria for authority to prescribe cannabis medicines in NSW (available here).
Background to the review and development of guidance resources
The researchers commissioned to undertake the evidence review conducted a systematic search of scientific databases. The search included randomised controlled trials conducted since 1980 and observational studies such as case reports, retrospective chart reviews and self-report surveys. Study reports were screened for quality and any potential bias. Information about the review process, including the protocol used can be found here.
The TGA has published the list of randomised controlled trials and other studies identified in the review, including the study reference, study type and a rating (grade) for the quality of evidence in each:
• Epilepsy (22 clinical trials and other studies): www.tga.gov.au/epilepsy-randomised-controlled-trials-and-other-studies
• Multiple Sclerosis (32 clinical trials and other studies): www.tga.gov.au/multiple-sclerosis-randomised-controlled-trials-and-other-studies
• Nausea & vomiting (50 clinical trials and other studies): www.tga.gov.au/nausea-and-vomiting-randomised-controlled-trials-and-other-studies
• Palliative Care (13 clinical trials and other studies): www.tga.gov.au/palliation-randomised-controlled-trials-and-other-studies
• Pain (99 clinical trials and other studies): www.tga.gov.au/pain-randomised-controlled-trials-and-other-studies