Medicinal cannabis is controversial. Read about the pros and cons, and what the latest research says. Click To Tweet

Medicinal cannabis. It’s a topic that most people are interested in. Some are for, some are against, and some of us just aren’t sure what to believe.

I recently wrote a patient information brochure on medicinal cannabis for a client. When I posted on my social media what I was writing about, there were many comments and opinions. It was clear that my followers at least, had an opinion on the benefits of medicinal cannabis. And a number of others were interested in reading what I discovered.

While I can’t share my client’s copy, I figured that I should compile all my research into a blog post that I can share with you.

My research was extensive. In fact, it was the most research I have ever done when writing on a health topic. It involved reading clinical trials, medical journals, excerpts of medical books, and lots of other information found on various medical and industry-related websites.

The topic is quite complex, but hopefully I’ve relayed the information here in a way that’s easy to understand. And I’ve included references — just in case you want to go and do some of your own reading on the topic.

So here it is — the answers to the questions most of us have regarding medicinal cannabis.

How long has cannabis been around for?

Cannabis has been used for over 5000 years [i] and is one of the oldest medicinal herbs to be documented.

In ancient times, cannabis was a common, versatile crop. grown for food (high-protein seeds and oils) and fibre, used to make rope and clothes. However, it wasn’t long before people discovered that it could be used medicinally. The ancient Chinese were the first to use it in a medical context. It eventually spread throughout Asia, the Middle East and Africa.

In ancient civilisations, cannabis was often used to treat pain and a variety of other conditions including gout, rheumatism, malaria and poor memory. Over time, people found more uses for the plant and it was touted as a cure for almost anything including coughs, jaundice, skin inflammation and incontinence. Interestingly, doctors throughout the ages cautioned against excessive use of cannabis, believing it had the potential for harmful side effects.

Due to its hallucinogenic properties, cannabis was also used for religious, spiritual and recreational purposes.

By the 1930s, the word cannabis had been substituted with marijuana. Because of the increasing popularity of the plant being used as a recreational drug (and the growing medical and social concerns associated with such use), cannabis was outlawed in Australia and many other countries.

Despite the criminalisation of cannabis, research into its medicinal properties continued, with some of the findings leading to strong support from various sectors of the medical field, advocating to make medicinal cannabis legal.

In 1996, California became the first US state to legalise medicinal cannabis, while Canada became the first country to legalise medical use of cannabis nationwide, in 2003. Many other countries have also legalised medicinal cannabis, including Australia.

However, recreational use of cannabis is still illegal in Australia.

What is medicinal cannabis?

Medicinal cannabis shouldn’t be confused with recreational cannabis. Medicinal cannabis is prescribed medication used to treat or relieve symptoms of a medical condition, or side effects of other conventional medications. It may also be referred to as medicinal marijuana.

Recreational cannabis (or marijuana) is the form of cannabis that people use to get ‘high’.

Medicinal cannabis is prescribed medication used to treat or relieve symptoms of a medical condition, or side effects of other conventional medications. Recreational cannabis is the form that people use to get ‘high’. Click To Tweet

How does medicinal cannabis work?

Researchers believe medicinal cannabis acts upon the body’s endocannabinoid system — a communications system in the brain and body that affects mood, memory, sleep, and appetite. Both our peripheral (outside the brain and spinal cord) and central nervous systems contain cannabinoids, which play a role in inhibiting pain. [ii]

Cannabinoids are also found in cannabis. To date, over 100 cannabinoids have been identified in cannabis. [iii] These act upon our endocannabinoid system in a similar manner to the cannabinoids our body makes. [iv]

I’ve heard the terms ‘THC’ and ‘CBD’. What do they mean?

The two major cannabinoids in cannabis that have been found to have medicinal benefits are called delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD).

THC is the compound that has a strong psychoactive effect — that means it changes the way someone thinks, feels and even behaves — and it’s the chemical that causes a person to get ‘high’. [v] In addition to the euphoric, relaxing and drowsy effects associated with this compound, THC has been found to relieve pain and have anti-inflammatory and antioxidant properties. [vi] Some research has also found it may help prevent or reduce vomiting. [vii]

CBD on the other hand, has anti-psychoactive effects — that means it controls or moderates the ‘high’ caused by THC. [viii] Research has also shown that CBD may reduce some of the other negative effects caused by THC, such as anxiety. [ix]

Medicinal cannabis products contain both THC and CBD.

What’s the difference between recreational and medicinal cannabis?

Both recreational and medicinal cannabis are made from the plant, cannabis sativa.

Both recreational and medicinal cannabis are made from the plant, cannabis sativa. However, their uses are totally different. Click To Tweet

Recreational cannabis is made from the dried leaves and buds of the plant. Typically, recreational cannabis contains more THC than CBD. Because recreational cannabis is unregulated, the amount of THC can vary between growers and farming methods and may be impacted by things such as soil quality, bacterial or fungal contamination, toxic chemicals, animal waste and heavy metals. This means the quality and purity of recreational cannabis may be in doubt.

Medicinal cannabis on the other hand is highly regulated. Generally, it contains higher levels of CBD, which means that users don’t experience the ‘high’ associated with recreational cannabis. Medicinal cannabis can be formulated to contain differing levels of CBD and TCH and is tightly controlled. That means that the specialists prescribing the drug know exactly what the medication contains. Because medicinal cannabis is made to stringent guidelines, there is no danger of it being contaminated by external factors.

In Australia medicinal cannabis comes in the form of oral capsules or oils, oral lozenges or spray, vaporisation disks, and creams.

The effectiveness of cannabis for various medical conditions will depend upon the types and amounts of cannabinoids in the product. [x]

Can’t you just smoke marijuana for the same effect?

No. Smoking cannabis for medicinal purposes is not recommended. Cannabis smoke associated with recreational cannabis contains significant amounts of toxic chemicals, such as ammonia, hydrogen cyanide and nitric oxide. [xi] In addition, recreational marijuana is not regulated like medicinal marijuana, which means there is no control as to what other substances may be present, which may also do harm. There is also no guarantee that recreational cannabis contains the components required for medicinal benefit.

Smoking cannabis cannot be used instead of medicinal cannabis. Click To Tweet

What are the benefits of using medicinal cannabis?

Scientific research supporting the benefits of medicinal cannabis as a treatment for a variety of conditions is still limited. However, evidence has found that it may be beneficial in some circumstances. Click To Tweet

Despite anecdotal evidence, and cannabis having a long history in treating a range of disorders, scientific research supporting the benefits of medicinal cannabis as a treatment for a variety of conditions is still limited. However, evidence has found that it may be beneficial in some circumstances.

Chronic pain

The most encouraging research is related to chronic pain, which is the most common reason patients turn to medical cannabis. [xii] The Australian Therapeutic Goods Administration (TGA) has reviewed the data from numerous published studies and believes the evidence supports the use of medicinal cannabis to treat chronic pain to a ‘moderate’ degree. [xiii]

There is also evidence that patients who use medicinal cannabis use fewer opiod drugs. [xiv] For example, one study found that patients who used medical cannabis for chronic pain recorded:

  • a 64% decrease in opioid use
  • better quality of life in patients with chronic pain, and
  • fewer medication side effects and medications used. [xv]

Multiple sclerosis (MS)

There is some evidence that cannabinoids can reduce pain in both MS-related neuropathic pain and non-MS-related neuropathic pain, but pain relief for many people may be modest. [xvi] There is modest-quality evidence in using medicinal cannabis for spasticity due to MS. [xvii]

Epilepsy in paediatric and adult patients

There is some evidence to support using medicinal cannabis in the treatment of certain childhood epilepsies.[xviii]

Cancer

There is modest-quality evidence for using medicinal cannabis chemotherapy-induced nausea and vomiting in adults. [xix] However, there is no evidence at this time that medicinal cannabis has any anti-cancer activity or that it can slow the progression of these conditions.[xx]

Arthritis and fibromyalgia

There is insufficient information regarding using cannabinoids for the treatment of pain associated with arthritis and fibromyalgia.[xxi]

While thousands of people around the globe swear that using medicinal cannabis helped them manage a number of medical conditions, there is currently inadequate scientifically-based evidence to support it being used to treat other conditions.

It’s also important to note that medicinal cannabis use is only recommended when other approved treatments have been tried and have failed to manage conditions and symptoms.

Are there any side effects?

All prescribed and over-the-counter medications have the potential for side effects. Medicinal cannabis is no different. Like other medications, the extent of side effects can vary between individuals, and may depend upon the type of product used, and the concentration levels of cannabinoids found in each product.

The side effects of medicinal cannabis are still being studied. Currently known side effects [xxii] [xxiii](both THC and CBD) include:

  • drowsiness
  • vertigo (dizziness) or problems with balance
  • difficulty concentrating, thinking and memory
  • nausea and vomiting
  • fever
  • increased or decreased appetite
  • dry mouth
  • diarrhoea.

THC and products high in THC have been associated with[xxiv]:

  • convulsions
  • feeling high or feeling dissatisfied
  • depression
  • confusion
  • hallucinations, paranoid delusions, or psychosis
  • cognitive distortion (having thoughts that are not true).

Like all medications, medicinal cannabis has side effects, and so isn't suitable for everyone. Click To Tweet

Is it safe for everyone to use?

No. Medicinal cannabis isn’t suitable for everyone. In particular, it’s not recommended for patients who [xxv]:

  • have a previous psychotic or concurrent active mood or anxiety disorder
  • are pregnant, planning to become pregnant, or breastfeeding
  • have unstable cardiovascular disease.

Because there is very limited evidence regarding how medicinal cannabis interacts with other medications, caution is advised if medicinal cannabis is to be taken with other medications.

It’s also important to know that anyone using medical cannabis should not drive nor operate machinery. Levels of THC, (the main psychoactive substance in cannabis) can still be detected in urine for quite some time after the last dose. [xxvi] As drug-driving is a criminal offence in Australia and carries penalties, anyone taking medicinal cannabis should discuss safe and legal driving with their doctor.

Doesn’t using cannabis lead you to use other drugs?

This has been a common argument among those opposed to medicinal cannabis. For many years, it has been believed that cannabis is a ‘gateway drug’ — a drug that leads people to try more harmful substances such as cocaine and heroin. This long-held theory is controversial and relates to smoking illegal cannabis, rather than taking medicinal cannabis. Using medicinal cannabis is tightly controlled and closely monitored by specialist doctors.

That said, a new study has found that heavy use of recreational cannabis is not related to injected drug use, and in fact is related to slower rates of injection initiation. [xxvii]

Why isn’t medicinal cannabis a mainstream medicine when civilisations have been using it for thousands of years?

In Australia, all medicines must be approved for sale by the TGA. For a medicine to be approved, it must meet strict guidelines. This involves reviewing the evidence to assess a medicine’s safety and efficacy (effectiveness), and ensuring the medicine meets manufacturing quality standards. Once approved, the TGA also decides how freely available the medication will be — whether via prescription or non-prescription.

The strongest evidence about the effects of medicines comes from clinical trials. These are research studies that are conducted in order to discover how well medicines work. Before it is available for sale, a medicine must pass a series of experiments, trials and approval processes.

As mentioned earlier, research into medicinal cannabis is still ongoing. In many cases there is very limited data available which makes it difficult to provide specific recommendations for treatment. Often, the products, doses and research methods used vary between studies, making it problematic to come to firm conclusions on the best way to use particular medicinal cannabis products. There is also limited information regarding dosages and potential side effects.[xxviii]

Who can access medicinal cannabis?

Medicinal cannabis is tightly regulated in Australia and is therefore subject to legal requirements. The TGA regulates the supply of medicinal cannabis in Australia.Currently, patients can only access medicinal cannabis through a specialist, who must meet certain requirements, obtain permits, and comply with relevant state laws. The laws surrounding medicinal cannabis vary from state to state and may affect whether a patient can access this type of treatment.Doctors who meet the above requirements can apply to the TGA to supply medicinal cannabis to certain patients through the Authorised Prescriber Scheme and the Special Access Scheme. Patients may be able to access medicinal cannabis through a specialist, their GP or if they are taking part in a clinical trial.

Research into the therapeutic benefits of medicinal cannabis is ongoing, and it may be some time until we have significant knowledge about using this as a treatment drug. Click To Tweet

What does the future hold?

While it shows therapeutic potential, cannabis is a highly complex plant and significant gaps remain in our knowledge. Research into the therapeutic benefits of medicinal cannabis is ongoing, and it may be some time until we have significant knowledge about using this as a treatment drug.Some of the research currently being conducted is looking at the potential for medicinal cannabis to treat epilepsy, schizophrenia and other psychotic disorders, type 2 diabetes, inflammatory bowel disease, some tumours, and drug dependency.[xxix]As you can see, the topic of medicinal cannabis is a complex one. As research continues, there are sure to be more discoveries, and perhaps better treatment and access to patients who need it.If you enjoyed this article and you’d like me to write an in-depth, highly researched article like this one, why not contact me.

Cheers
Nerissa

References:

[i] Honorio T. Benzon,et al., Essentials of Pain Medicine, 4th edition, 2018 Elsevier, p 509

[ii] ibid. Essentials of Pain Medicine, 4th edition, 2018 Elsevier, p 17

[iii] Hindocha, Chandni et al., Acute effects of delta-9-tetrahydrocannabinol, cannabidiol and their combination on facial emotion recognition: A randomised, double-blind, placebo-controlled study in cannabis users, European Neuropsychopharmacology, March 2015, Volume 25 , Issue 3 , 325 – 334 https://www.europeanneuropsychopharmacology.com/article/S0924-977X(14)00325-3/fulltext

[iv] Hill, Kevin P. et al. Cannabis and Pain: A Clinical Review. Cannabis and Cannabinoid Research2.1 (2017): 96–104. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5549367/

[v] op.cit. Essentials of Pain Medicine, 4th edition, 2018 Elsevier, p 454

[vi] Russo, Ethan B. Cannabinoids in the Management of Difficult to Treat Pain. Therapeutics and Clinical Risk Management 4.1 (2008): 245–259. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503660/

[vii] Victorian Law Reform Commission, Medicinal Cannabis. August 2015, p 40 http://lawreform.vic.gov.au/sites/default/files/VLRC_Medicinal_Cannabis_Report_web.pdf

[viii] Zuardi AW et. al, A critical review of the antipsychotic effects of cannabidiol: 30 years of a translational investigation, Current Pharmaceutical Design, 2012;18(32):5131-40 https://www.ncbi.nlm.nih.gov/pubmed/22716160

[ix] World Health Organisation, Update of Cannabis and its Medical Use, 2015 p 17 http://www.who.int/medicines/access/controlled-substances/6_2_cannabis_update.pdf

[x] op.cit, Medicinal Cannabis, p 20.

[xi] op cit. Update of Cannabis and its Medical Use, p 5

[xii] National Academies of Sciences, Engineering, and Medicine, The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research, 12 January 2017, p 85 http://books.nap.edu/openbook.php?record_id=24625

[xiii] Therapeutic Goods Administration, Guidance for the use of medical cannabis in Australia: Patient Information, 21 December 2017 https://www.tga.gov.au/publication/guidance-use-medicinal-cannabis-australia-patient-information

[xiv] op.cit The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research, 12 January 2017 p 87

[xv] Boehnke, Kevin F. et al., Medical Cannabis Use Is Associated With Decreased Opiate Medication Use in a Retrospective Cross-Sectional Survey of Patients With Chronic Pain, The Journal of Pain, June 2016, Volume 17 , Issue 6 , 739 – 744, https://www.jpain.org/article/S1526-5900(16)00567-8/abstract

[xvi] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xvii] op.cit The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research, 12 January 2017, p85

[xviii] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xix] op cit.  The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research, p 85

[xx] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xxi] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xxii] healthdirect, Medicinal Cannabis, https://www.healthdirect.gov.au/medicinal-cannabis

[xxiii] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xxiv] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xxv] op.cit. Guidance for the use of medical cannabis in Australia: Patient Information

[xxvi] op.cit. Guidance for the use of medical cannabis in Australia: Patient Information

[xxvii] Reddon, Hudson et. al, Cannabis use is associated with lower rates of initiation of injection drug use among street‐involved youth: A longitudinal analysis, Drug and Alcohol Review, 12 February 2018, https://onlinelibrary.wiley.com/doi/abs/10.1111/dar.12667

[xxviii] op.cit Guidance for the use of medical cannabis in Australia: Patient Information

[xxix] op.cit, Medicinal Cannabis.

Other References:

Alcohol and Drug Foundation, Medicinal Cannabis, last updated 6 June, 2018 https://adf.org.au/drug-facts/medical-cannabis/

Medical Daily, A Brief History of Medical Cannabis: From Ancient Anesthesia to the Modern Dispensary, 21 January 2016, https://www.medicaldaily.com/brief-history-medical-cannabis-ancient-anesthesia-modern-dispensary-370344

Therapeutic Goods Administration, Access to medicinal cannabis products, 21 March 2018, https://www.tga.gov.au/access-medicinal-cannabis-products-1

Therapeutic Goods Administration, Guidance for the use of medicinal cannabis in the treatment of chronic non-cancer pain in Australia, 21 December 2017, https://www.tga.gov.au/publication/guidance-use-medicinal-cannabis-treatment-chronic-non-cancer-pain-australia#s1

Therapeutic Goods Administration, Guidance for the use of medicinal cannabis in Australia: Overview, 21 December 2017 https://www.tga.gov.au/publication/guidance-use-medicinal-cannabis-australia-overview

Penny F.Whiting et. al Cannabinoids for Medical Use: A Systematic Review and Meta-analysis, Journal of the American Medical Association, 2015 Jun 23-30; 313(24): pp2456-73 https://www.ncbi.nlm.nih.gov/pubmed/26103030

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