Medicinal cannabis: the facts

The use of medicinal cannabis has been a popular and often controversial topic for public conversation in recent months. We’ve explored the issue in depth and in this article, cut through the background noise to bring you the facts about its potential use in the treatment of breast cancer.

Recent changes in Commonwealth and state laws mean that medicinal cannabis products can now be used in Australia to assist in the treatment and management of cancer-related symptoms and side effects.

In terms of cannabis and its relationship with cancer, it’s important to note there is currently no evidence that medicinal cannabis is an effective treatment for cancer. Anecdotal evidence from people diagnosed with cancer say it helps to relieve symptoms such as pain, nausea and vomiting, and there is some evidence to support this.

Equally, there are many conventional drugs available that also help to manage these symptoms, meaning medicinal cannabis may not be the answer for everybody.

There is a crucial distinction to be made between medicinal and recreational cannabis.

According to the Australian Alcohol and Drug Foundation, medicinal cannabis is prescribed to relieve symptoms of a medical condition, such as epilepsy, while recreational cannabis is the form of cannabis that people use to get ‘high’.

There are more than 100 cannabinoids in the cannabis plant including THC, the cannabinoid associated with the psychoactive effect associated with smoking or ingesting marijuana recreationally.

The pharmaceutical products derived from the cannabis plant involve isolating useful cannabinoids and refining their production to minimise harm.

Legalisation of medicinal cannabis in Australia

With the exception of one type (for multiple sclerosis), medicinal cannabis products are not registered for use in Australia. This means they can only be legally accessed through Australian pathways for unapproved medicines.

Doctors can apply for approval to prescribe a medicinal cannabis product through two pathways: The Special Access Scheme (SAS) is for individual doctors wishing to apply on behalf of an individual patient. The Authorised Prescriber Scheme (APS) is for individual doctors wishing to prescribe for a class of patients with the same indication.

Some people may also be able to access medicinal cannabis through a clinical trial; your breast cancer clinician will be able to tell you if there are any suitable trials available for you.

Who can prescribe medicinal cannabis?

Medicinal cannabis can only be prescribed by a registered medical practitioner if they receive approval from the Therapeutic Goods Administration (TGA) and the relevant state or territory government.

Before prescribing medicinal cannabis, your doctor will assess you to decide whether a medicinal cannabis product is appropriate for your condition and individual circumstances. Your doctor will take a medical history and a family health history, while also taking into consideration your current medications and any problems with drug dependence and substance abuse.

If your doctor decides a medicinal cannabis product is appropriate, they will apply on your behalf for approval to import and supply these products through the SAS.

If the particular medicinal cannabis product recommended for you is not currently available in Australia, your doctor can apply to the Office of Drug Control to import it.

What does it cost?

Reports indicate most medicinal cannabis products are very expensive and as it is not included on the Pharmaceutical Benefits Scheme (PBS) individuals will pay the full cost.

If you are enrolled in a medicinal cannabis clinical trial, the cost is covered by the trial.

How is medicinal cannabis taken?

Medicinal cannabis can be taken in a number of ways: raw cannabis, which is vaporised (not smoked), cannabis extract in oil, tinctures (extracts soaked in ethanol), oro-mucosal spray (i.e. spray onto the cheek inside the mouth), and topical gel, cream or patch.

Smoking the cannabis plant is harmful and is not recommended.

What are the side effects of medicinal cannabis?

The side effects of medicinal cannabis are not well understood and can vary depending on the type and dose of the product, and between individuals. Known side effects include: fatigue and sedation, vertigo, nausea and vomiting, fever, decreased or increased appetite, dry mouth, diarrhoea, impaired coordination and anxiety.

Cannabis and palliative care

There is minimal evidence around the effectiveness of medicinal cannabis for people suffering chronic pain caused by metastatic cancer.

It is also possible that medicinal cannabis may interact with chemotherapy and other palliative care medications, making them less effective.

For this reason, medicinal cannabis is generally only considered after standard conventional treatments have stopped working.

More research is needed

Research is currently being undertaken in Australia and overseas to understand the potential benefits, limitations and safety issues associated with medicinal cannabis for people with cancer.

In Australia, trials are investigating a range of uses, including whether medicinal cannabis can improve quality of life in people with metastatic (advanced) cancer, and whether it can prevent chemotherapy-induced nausea and vomiting where standard treatments are ineffective.

Where to find more information

Your breast cancer specialist will be the best person to talk to about whether medicinal cannabis may be helpful for you.

If you are looking for information about medicinal cannabis online, ensure it is accurate and up to date.

Issue 86
Autumn 2020