Cannabis and chronic pain in Australia

Cannabis and chronic pain in Australia
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Painaustralia tells MCN Quarterly about the use of cannabis to treat chronic pain.

Despite making up around 60% to 70% of the customer base for Australia’s medical cannabis market, chronic pain patients in Australia still face a variety of barriers to access, ranging from issues around cost to the ongoing reluctance of many doctors to prescribe cannabis as a medicine.

MCN Quarterly speaks with Australia’s leading national advocacy body for patients living with pain, Painaustralia, about the benefits and drawbacks of cannabis in the treatment of chronic pain.

Can you tell me a bit about Painaustralia and the National Pain Strategy?

Painaustralia is the national advocacy body working to improve the quality of life of people living with pain, their families and carers, and to minimise the social and economic burden of pain. Painaustralia represents the interests of a broad membership that includes health, medical, research and consumer organisations. Our work and mission is informed by a few key documents, including the National Pain Strategy and the National Strategic Action Plan for Pain Management.

Established in 2011, our focus is to work with governments, health professional and consumer bodies, funders, educational and research institutions, to facilitate Australia-wide implementation of the National Pain Strategy and the National Strategic Action Plan for Pain Management, which is a blueprint for the treatment and management of acute, chronic and cancer pain. Australia was the first country in the world to develop a national framework for pain, and it generated worldwide interest, particularly in the USA, Canada and Europe.

What benefits does medical cannabis offer in the treatment of chronic pain?

Most people who seek medicinal cannabis do so for pain management; and there is growing interest and expectation around the use of these products to treat a range of conditions. So far there is little evidence about suitable doses of individual cannabis products, such as randomised controlled trials or systematic reviews, which could enable definitive statements on the effectiveness of medicinal cannabis. This lack of evidence makes it difficult for practitioners to prescribe medicinal cannabis, despite community expectations that these products will be made available to treat chronic pain.

With chronic pain, there is an overarching need to expand availability of safe and effective treatments; as current treatments are not adequate. Studies to date have not yet systematically addressed this question in a large population of people taking medicinal cannabis for chronic pain. Despite the legalisation and decriminalisation of cannabis in some places in Australia and overseas, there have only been a limited number of well-designed clinical studies on medicinal cannabis1 and its role in treating chronic pain.

We know more about the role of cannabis products in treating neuropathic pain than other forms of pain. Neuropathic or nerve pain is difficult to treat and can be debilitating. It can be caused by damage, injury or dysfunction of nerves due to trauma, surgery, disease or chemotherapy. Neuropathic pain can be the primary symptom of a standalone condition, such as multiple sclerosis or complex regional pain syndrome; or it can be associated with other conditions or forms of pain. There may be a niche role for medicinal cannabis – pending further research – in the management of complex chronic pain with distress, especially in the case of neuropathic pain.

The strongest scientific evidence in favour of medical cannabis relates to its effectiveness in treating childhood epilepsy syndromes, such as Dravet syndrome and Lennox-Gastaut syndrome (LGS), which typically do not respond to antiseizure medications. Painaustralia notes that these indications are the only ones that the Pharmaceutical Benefits Advisory Committee (PBAC) is considering for potential listing of CBD on the Pharmaceutical Benefits Scheme.

In what areas should additional research be conducted to support the role of cannabis in best practice pain management?

Additional randomised controlled trials and systematic reviews are required to understand the effectiveness and safety of medicinal cannabis for pain management, as well as to shed light on suitable doses of individual cannabis products like CBD. Importantly, as the health risks associated with cannabis come under increasing scrutiny, pharmacovigilance (monitoring the effects of medicinal cannabis) during its use may uncover other problems.

The use of cannabis, particularly its principal psychoactive constituent, tetrahydrocannabinol (THC), is associated with health risks including lung disease (when smoked), cardiovascular disease, acute pancreatitis, and cannabinoid hyperemesis syndrome.2 Cannabis users are also at increased risk for occupational injuries; and cannabis-associated ‘drugged driving’ which can be fatal. Finally, the myth that medicinal cannabis is nonaddictive has been dispelled by studies of forced abrupt cessation of use indicating potential rebound hyperalgesia and craving.3

The potential for drug-drug interactions of medicinal cannabis with other commonly used medications is high.4,5,6 It is important to note that medication alone is not helpful for the management of chronic pain and patients need to adopt other strategies. All medications, including medicinal cannabis, have side effects and many can be harmful if used over the long term. We need to monitor the impacts of changes to any scheduling that considers societal costs of overuse of medications and a shift from lifestyle and holistic interventions to pharmaceutical interventions. In short, we need to weigh the costs against the benefits.

How difficult is it for patients with chronic pain to access cannabis-based medicines in Australia? What barriers or challenges do patients and their carers face?

There is little evidence about suitable doses of individual cannabis products like CBD, such as randomised controlled trials or systematic reviews, to enable definitive statements on the effectiveness of medicinal cannabis for pain management. This lack of evidence makes it difficult for practitioners to prescribe, despite community expectations that these products will be made available to treat chronic pain.

Several access issues remain, with poor rates of uptake by both general practitioners and hospitals and multidisciplinary pain services, leaving a large unmet demand across the chronic pain population group. This has made the sector vulnerable and open to exploitation through ‘access clinics’, which are usually supported by the pharmaceutical industry and therefore expose consumers to the increased risk of single modality of care, as well as high out of pocket costs.

Pain specialists have reported encountering many barriers in obtaining the necessary licence to become an ‘Authorised Prescriber’. Even practitioners based at large hospitals who have applied with the support of ethics committees have been denied access, as the requirements include listing every single product they wished to use, which is a difficult task as products are constantly changing. Thus, practitioners are forced to rely on single person applications each time, with a continuous audit and research programme: an additional barrier to access.

Many questions also remain around the effect of medicinal cannabis on legal requirements for driving in Australia. It is illegal to drive with THC in the system, yet trace amounts of THC may be found in CBD products (if plant-derived); and because it is fat-soluble and stored by the body, THC can accumulate to detectable levels (and potentially impairment levels) with regular CBD use. There is a potential for false positive roadside tests and high-sensitivity blood analysis being positive.

Consumers also expect all over-the-counter (OTC) drugs to be regulated for consistency. Consumers may be unaware of small amounts of THC which can remain in plant-derived CBD concentrates, or of the safety of people on high-dose CBD.

Consumer sentiment remains that enabling access to medicinal cannabis will hopefully make it more accessible to those who may benefit from it. This applies to those in regional areas who may not have a choice of doctors or specialists who are up to date with medicinal cannabis as a treatment and may be unlikely to prescribe it, for those who struggle to find the time and the money to get prescriptions regularly, etc.

Is Australia’s medical cannabis licensing process fit for purpose, in terms of helping patients in need?

Research released by the medicinal cannabis sector in Australia indicates that people living with chronic pain, who make up an estimated 60% to 70% of the market for medicinal cannabis, are paying about $350 a month for their treatment using cannabis products.7

As there are currently no medicinal cannabis medications subsidised by the Pharmaceutical Benefits Scheme (PBS), this means patients are required to cover all of the relevant costs out of pocket. OTC access to CBD has the potential to significantly add to the chronic pain related costs incurred by individuals in Australia. The out-of-pocket cost implications of medicinal cannabis will therefore remain a huge barrier in access for consumers.

Painaustralia has been involved in several policy and research forums that discuss the medical efficacy of medicinal cannabis products. In particular we are concerned to note that due to the current provisions of the Special Access Scheme in Australia, many manufacturers of medicinal cannabis products are reluctant to participate in research that can demonstrate the efficacy and effectiveness of these products.

This is a trend that was noted in the Senate report on current barriers to patient access to medicinal cannabis in Australia which notes evidence that large policy changes such as legalisation of marijuana have also removed incentives for the industry to fund controlled clinical research into the safety and effectiveness of cannabis-based medicines. It has also not increased researchers’ access to medical cannabis products for investigator-initiated clinical trials.8

References

1 Op. Cit TGA 2017.

2 Zhang MW, Ho RC. The Cannabis Dilemma: A Review of Its Associated Risks and Clinical Efficacy. J Addict. 2015: 707596.

3 Carr, D, Schatman, M. Cannabis for Chronic Pain: Not Ready for Prime Time. Am J Public Health. 2019 January; 109(1): 50–51. Published online 2019 January. doi: 10.2105/AJPH.2018.304593

4 Huestis, MA, Solimini, R, Pichini, S, Pacifici, R, Carlier, J and Busardò, FP, 2019. Cannabidiol adverse effects and toxicity. Current neuropharmacology, 17(10), pp 974-989.

5 Qian, Y, Gurley, BJ, Markowitz, JS, 2019. The potential for Pharmacokinetic Interactions Between Cannabis Products and Conventional Medications. J. Clin Psychopharmacol. 2019 Sep/Oct, 39 (5) p462-471.

6 Expert Committee on Drug Dependence, World Health Organization, 39th meeting, Geneva, 6-7 November 2017. https://www.who.int/medicines/access/controlled-substances/5.2_CBD.pdf

7 Cannabis Access Clinics 2018. Price of medicinal cannabis halves but still too expensive for many. Access online here.

8 Hall and Farrell, Submission 68, p. 10. Current barriers to patient access to medicinal cannabis in Australia.

Painaustralia
www.painaustralia.org.au

This article is for issue 4 of Medical Cannabis Network. Click here to get your free subscription today.

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1 COMMENT

  1. I cannot believe you are still flogging the dead horse of addictiveness. Please extend your research. It is no more addictive than the general rate of addiction which is a little under 10%. It can successfully be used as an “exit” drug, contrary to popular belief, HELPING people with other addiction. People can crave any substance, so that is not a measure of addictiveness. There are very few physical withdrawal symptoms, rather a return to previous symptom levels. All we ask is to follow the basic tenet of medicine “First, do no harm’. It is the LEAST harmful of ALL the drugs we use for chronic pain, with a comparable favourable side effect profile, with an already proven record of reducing opioid use, and opioid-accociated deaths, and it is impossible to overdose. And please remember, euphoria is an acceptable side effect.

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