‘In terms of Australia, there are mistakes that can be learnt from Canada’: we speak with an expert about the clinical use of medicinal cannabis
Medicinal cannabis is a burgeoning area in Australia, with the Federal Government recently announcing $3 million in investment from the Medical Research Future Fund (MRFF) to examine the benefits of medicinal cannabis for pain, symptom and side effect management for cancer patients.
Medicinal cannabis products are not registered medicines in Australia, and none are subsidised through the PBS, so they can only be accessed through special pathways available for unapproved medicines (SAS) or the Authorised Prescriber Scheme.
To date, the TGA has approved SAS applications including, but not limited to, indications such as chemotherapy-induced nausea and vomiting; refractory paediatric epilepsy; palliative care indications; cancer pain; neuropathic pain; spasticity from neurological conditions; and anorexia and wasting associated with chronic illness (such as cancer).
Medicinal cannabis can only be prescribed by a registered medical practitioner after a thorough assessment to decide if the treatment is appropriate for the patient’s condition and individual circumstances.
The AJP sat down with Canadian physician Dr Danial Schecter, Director of Global Medical Services at Spectrum Therapeutics*, to discuss the benefits, risks and future of medicinal cannabis in Australia.
1. How would you describe the Canadian policy landscape for medicinal cannabis, and how could this translate to Australia – would it look similar or quite different?
Across any country, it is important for doctors to be able to communicate with their patients about a range of treatment options, including medicinal cannabis.
In Canada, a key area for reform was education. There needs to be more balanced and regular education programs in place to support issues such as endocannabinoid science, dosing of THC and CBD, patient screening and monitoring, safety concerns and adverse event reporting.
In terms of Australia, there are mistakes that can be learnt from Canada. This includes the struggle to find a way to balance the need for education with the need for independent review and the interests of the emerging cannabis industry.
Finding a balance between these important factors is critical to supporting and protecting patients seeking treatment with medicinal cannabis.
2. What are the main health uses and benefits of medicinal cannabis?
Medicinal cannabis represents a unique class of medicine, as it’s rare for any one class of drug to have such a broad spectrum of effects. This includes treating a wide range of symptoms across pain, spasticity, nausea, anxiety and seizures.
From experience in the medical field, these effects are supported by enormous scientific advances in our understanding of the body’s own endogenous system (also known as the endocannabinoid system) of cannabinoid molecules and receptors, which plays an important role in a variety of conditions and processes.
This endocannabinoid system (ECS) is involved in many physiological functions, including inflammation, sleep, pain, memory, digestion, immune function, neuroprotection and more. The phytocannabinoids (such as THC and CBD) are produced by the cannabis plant and also interact with the receptors of your ECS. This could partly explain why cannabis seems to affect such a vast range of conditions and symptoms.
3. Are there any risks that come with medicinal cannabis use?
Like any drug, there are potential side effects. The impact of THC on the cannabinoid receptors in the brain may have both positive and negative effects.
Negative effects often depend on the mode of administration (whether taken through inhalation or oral), dose (especially related to THC), experience with cannabis, age of patient and frequency of use.
Under medical supervision, at therapeutic doses, cannabinoids are very well tolerated and may have only mild-moderate effects, such as dizziness and drowsiness. Non-medicinal or field cannabis, as used for recreational purposes and often in large doses, may have important effects, especially in young people on cognition, brain development and psychosis in people at risk of schizophrenia.
In medical use, side effects can be reduced by using low doses and by comprehensive screening for patients with an active history of mental health disorders.
4. How is cannabis used for pain reduction and reducing the use of opioid medications?
I was part of a team at McGill University that led one of the largest studies looking at the long-term safety of medical cannabis use by patients with chronic pain. The study enrolled more than 400 adults with severe and intractable chronic pain, half of whom used a standardised cannabis product under real-world conditions, and half of whom did not.
We observed no difference between groups in serious adverse events, cognitive function, biochemistry, and hematology. Yet over the one-year follow-up period, the cannabis group experienced a significant improvement in their levels of pain, symptom distress, mood, and quality of life.
There are a number of ways medicinal cannabis can help reduce patient opioid dosage. The first is that it can work synergistically with opioids, meaning that using both (opioids and cannabinoids) can lead to greater results. Essentially, if 1+1=2, you now have 2+2=4.
Secondly, pain is very complex and opioids target a specific aspect of pain. Because cannabinoids are a multi-molecule, it impacts a series of functions on how we react and cope with pain, as well as alters our ability to deal with pain for longer.
Another way it can help reduce opioid use is by providing people with better sleep. If you sleep better at night, you generally have more pain resilience the following day as your pain threshold will be higher.
5. What do pharmacists need to know about medication management and cannabis?
Even though medicinal cannabis can only be prescribed by a doctor, it is important that all members of the patient’s healthcare team work together and have a current working knowledge on medicinal cannabis.
As such, we are in the process of creating a free, accredited online education module which will cover topics such as pharmacotherapy; evidence, indications and contraindications; drug interactions; and prescribing and dispensing requirements, including implementing appropriate systems in pharmacy to manage medicinal cannabis. Additionally, future opportunities to be included in pharmacovigilance programs will also be made available.
Any pharmacists who wish to pre-register for access to the module can submit their details at www.praxhub.com/medicinal-cannabis-registration. Pharmacists will be notified when the module is available before the end of 2019.
*Dr Danial Schecter is the Director of Global Medical Services at Spectrum Therapeutics, a biopharmaceutical company that manufactures cannabis-based products and conducts research in cannabinoid science.
Dr Schecter is the co-founder and medical director of Canabo Medical Clinic (formerly the Cannabinoid Medical Clinic), one of the largest referral-only clinics in Canada specialising in cannabinoid medicine. He is also a practising family physician in Toronto.
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