Opinion

Medicinal cannabis: A GP examines the evidence


Vicki Kotsirilos


9/05/2018 12:06:07 PM

GP and integrative medicine practitioner Dr Vicki Kotsirilos writes for newsGP about existing evidence for the provision and use of medicinal cannabis.

Medicinal cannabis products are oil-based or liquid-based cannabis or cannabinoid extracts that are more slowly absorbed with oral administration. (Image: AAP/Alex Murray)
Medicinal cannabis products are oil-based or liquid-based cannabis or cannabinoid extracts that are more slowly absorbed with oral administration. (Image: AAP/Alex Murray)

Due to strong demand and lobbying from patient advocacy groups, Australia’s federal and state governments improved lawful accessibility of medicinal cannabis in 2016. This has put increasing demands on many Australian GPs to prescribe medicinal cannabis products for their patients.
 
The Therapeutic Goods Administration (TGA) defines medicinal cannabis products as ‘a range of cannabis preparations intended for therapeutic use, including pharmaceutical cannabis preparations, such as oils, tinctures and other extracts’.
 
These products should not be confused with marijuana smoking for recreational use (an important social issue of its own), usually heated and inhaled with tobacco. This is a harmful process that causes serious health problems, such as respiratory disease, addiction, depression, anxiety and psychotic episodes, the latter mainly seen in young people with frequent use. The smoking of any substance is likely to have an adverse effect on health and cause respiratory diseases.
 
Medicinal cannabis products are cannabis or cannabinoid extracts in very small doses. They are oil-based or liquid-based and are more slowly absorbed with oral administration. Other methods of administration include transdermal, oro-mucosal spray and vaporising. They are usually not heated, (apart from vaporising methods with lower temperature heats), usually swallowed, absorbed sublingually or applied transdermally. They do not share the same risks as the recreational variety and are only recommended in unwell patients for therapeutic purposes.
 
Medicinal cannabis products are emerging around the world as important agents for relieving distressing symptoms in people with certain conditions, especially if conventional medicines have not been effective. 
 
The cannabis plant consists of a number of active constituents, including terpenes and many cannabinoids. The delta-9 tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) are the most well known and active components and their ratios determine choice of product for treatment of disease.  
 
Medicinal cannabis products in Australia are now accessible only to appropriate patients for certain medical conditions. Anecdotal evidence suggests overseas medical doctors and Australian GPs are finding them of value, particularly for patients who have suffered side-effects and are not finding symptomatic relief with their usual medications and treatments.
 
The majority of patients seeking medicinal cannabis products are those with chronic severe pain, and those who are experiencing terminal illnesses (such as cancer) and intractable conditions (such as spasticity associated with multiple sclerosis and severe uncontrolled epilepsy).
 
In Australia, Nabiximols (Sativex oromucosal spray), an extract of cannabis, is available on the Australian Register of Therapeutic Goods (ARTG) on authority by specialists for its clinical benefits of muscle relaxation for spasticity associated with multiple sclerosis, if intolerant or not responding to anti-spasmodic medication.
 
International scientific research suggests there may be clinical benefits to support the use of medicinal cannabis products for certain medical conditions. There is no evidence it is more harmful or riskier than opiates, which are widely prescribed by GPs and may actually help reduce mortality from opioid overdose.
 
Due to heterogeneity of medicinal cannabis products (the mixture of cannabinoids can change from crop to crop), dosages being tested in studies and research methods varying between studies, it is still not clear what products, strains, types, dosages and strengths of these products are particularly useful for which conditions. This has made it difficult to extrapolate findings, make generalised conclusions and create firm clinical guidelines around their use. (Refer to the TGA website for more information.)
 
A number of systematic reviews and guidelines on prescribing exist. A recent review of the evidence in the European Journal of Internal Medicine suggests medicinal cannabis products may be useful for chronic pain in adults, chemotherapy-induced nausea and vomiting and spasticity associated with multiple sclerosis, and assist with secondary sleep disturbances.
 
As medicinal cannabis products are considered unapproved drugs in Australia, they can only be accessed through the TGA Special Access Scheme or Authorised Prescriber Scheme.
 
The application process for a medicinal cannabis permit is onerous, lengthy and difficult for GPs, as it involves obtaining two permits – from the TGA Special Access Scheme and the relevant state poisons department for a schedule 8 permit. This has been a deterrent for GPs to prescribe medicinal cannabis for suitable patients.
 
The announcement following the recent Council of Australian Governments (COAG) Health Council in Sydney on 13 April – to streamline application and approval process for unregistered medical cannabis products – is encouraging and will hopefully improve and streamline prescribing for GPs.  
 
In addition, it is necessary to obtain approval by another specialist for the use of medicinal cannabis for each patient prior to an application. This often delays prescribing for patients who may benefit, as these specialists are often booked out for months and may disapprove of its use.
 
Medicinal cannabis products are considered of low toxicity by the TGA, but are best contraindicated in patients with a history of psychotic disorder, concurrent active mood or anxiety disorder, pregnancy, breastfeeding, planning pregnancy and unstable cardiovascular disease until further research is available. They can also interact with medication, particularly with drugs metabolised by, or inhibit or induce, cytochrome P450 (CYP450) enzymes.
 
While medicinal cannabis is still experimental and new in Australia, there should be no delay in treatment for unwell patients who are in need, such as those experiencing severe chronic pain not relieved by usual medication, chemotherapy-induced vomiting and nausea, and spasticity associated with multiple sclerosis. It is important to note that the TGA advocates that medicinal cannabis be used as a last resort treatment.
 
Further clarification is needed in the near future, such as advice that a patient cannot drive while undergoing treatment with medicinal cannabis containing THC, as research has shown a patient may test positive to a random drug test while being treated with medicinal cannabis and will be subject to current laws that prohibit driving under the influence of cannabis.
 
There is a need for more research and it is encouraging that institutions such as the University of Sydney and University of Western Sydney are actively researching medicinal cannabis products.
 
The RACGP believes GPs who hold a Fellowship are recognised as specialists GP. GPs are in an excellent position to safely prescribe medicinal cannabis products, without the need to refer to other specialists for approval. GPs can monitor for risks and side-effects, identify drug interactions, and report adverse events to the TGA.
 
Just as GPs are well trained to provide prescriptions for drugs of dependency and analgesia for patients when appropriate, the same principles would apply to prescribing medicinal cannabis products.
 
Access the RACGP’s Medicinal use of cannabis products position statement for more information.



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FS   11/05/2018 7:04:12 AM

Good way to fuel the discussion, but as professionals we should be careful what message regarding cannabis we want to put out in the public realm.

There is no good evidence for using it as primary option for anything other than N/V in chemo patients. It is at best 3rd or 4th line in treating pain and there are various other meds with WAY better evidence in spasticity.

On the flipside, we should not overstate the harms/side effects as some side effects are probably what makes them effective in some instances. And comparing them with other meds like opioids, why try to play the 2 against each other? Each will have their place if use appropriately with proper training and selecting the correct individuals to trail it on.

We should learn form the opioid crisis (we created ourselves), and maybe step into this with caution and use the best available evidence (not the 'some studies show it may help with...') and pick out patients carefully before initiating

Treat it like a regular medication, add it to the armoury, but don't compare to other medication or drugs of abuse and therefore get caught up in the public outcry/demand for its unsolicited use.


vineet Jadhav   11/05/2018 10:18:29 AM

"The RACGP believes GPs who hold a Fellowship are recognised as specialists GP. GPs are in an excellent position to safely prescribe medicinal cannabis products, without the need to refer to other specialists for approval. ".
It is so disappointing to see such a comment from the RACGP which is meant to be an advocacy for General Practitioners. This is the standard comment, used be various government run programs which are excuses for cost cutting, and deprive patients of specialist services, as Medicare/Government agencies do not want to increase specialist services/doctors as it costs them too much. So the best idea they can come up with is to dump this on GP's who are "in a unique position" to provide this service.
Just as a reference to this article can I ask how many doctors on this forum/GP'S/specialist alike have had training in prescribing cannabis, how many are familiar with dosing, which MIMS guide has this information. ?? Which pharmacology text has this information.
The introduction of any drug with narrow therapeutic index should rightly be introduced via specialist services, or training programs be available for GP's who are interested in the same.


Ian Brighthope   11/05/2018 12:54:14 PM

Medicinal Cannabis (tincture of oil of Cannabis) is a herbal medicine and must be recognised as such. Until 1937 it was available through pharmacies in Australia. There were over 100 indications for its clinical use in the US Pharmacopeia. There are many GPs in Australia with training and qualifications in herbal medicine who should be permitted to prescribe it without specialist backing. There is a special course being conducted in Melbourne on the 19 and 20 May.
www.medicalcannabiseducation.org.au
A time to learn the facts, data and reality.


Ruth Gawler   11/05/2018 1:55:12 PM

This is such an appalling situation presently with many patients seeking illegal channels for medical treatment. What a ridiculous run around with the TGA and individual applications. Why not just make it an S8 drug and put it with all the others !


Simone Merkin   11/05/2018 11:07:12 PM

Well meaning but misleading information. Fact: NDARC’s most thorough review published Dec 2017, NNT: overall 1 person in 22 gets 30 % chronic pain relief using a cannabinoid prep. Get real, acupuncture is better without the harms. Are our specialists in life this desperate not to check their facts ?


Joe Kosterich   13/05/2018 7:07:17 PM

Excellent piece Vicki. Certainly Medicinal cannabis is not first line, nor a panacea and not side effect free. However, it is much safer option than opioids in chronic pain. There have been no recorded deaths from overdose. It needs to be looked at like any other medication and used where benefit outweighs risk. It should not be harder to prescribe than more harmful medications. Note- the commenter is medical advisor to Little Green Pharma a medicinal cannabis company. www.lgpharma.com.au


Simone Merkin   15/05/2018 6:39:42 AM

Cannabinoids are not safer than opioids. Fact: The Respected US NASEM 2017 review shows 20% cannabis users with Cannabis Use Disorder (p333); that suicide (p314) anxiety (p318) and psychosis (p289) are increased; cognitive - motor effects are noted from use in the last 24 hours affecting pilots, skippers and drivers on roads near our children (p267/217). We are GP Specialists, we work with scientific fact, beware of glib false claims.


Simone Merkin   15/05/2018 8:36:10 AM

Cannabinoids are not safer than opioids. Fact: The Respected US NASEM 2017 review shows 20% cannabis users with Cannabis Use Disorder (p333); that suicide (p314) anxiety (p318) and psychosis (p289) are increased; cognitive - motor effects are noted from use in the last 24 hours affecting pilots, skippers and drivers on roads near our children (p267/217). We are GP Specialists, we work with scientific fact, beware of glib false claims.


Dr Vicki Kotsirilos AM   1/06/2018 6:36:53 AM

This study highlights that Medicinal Cannabis helps reduce Opioid pain reliever (OPR) hospitalizations:

“Conclusion:
Medical marijuana policies were significantly associated with reduced OPR-related hospitalizations but had no associations with marijuana-related hospitalizations. Given the epidemic of problematic use of OPR, future investigation is needed to explore the causal pathways of these findings.“

Source:
https://www.drugandalcoholdependence.com/article/S0376-8716(17)30076-5/abstract


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