Medicinal Cannabis

Cannabis plant with oil

MEDICINAL CANNABIS IS ONLY OFFERED BY CERTAIN DOCTORS IN THE CLINIC. An upfront deposit is generally required to make this long appointment. Please do not book on-line. And ideally prepare for the appointment by reading through this page.

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History

Prior to 1937, cannabis had enjoyed a 5000 year history as a therapeutic agent across many cultures. By the late 19th Century, cannabis-based medications were manufactured by Burroughs-Welcome & Co. (GSK), Bristol-Myers Squib, Parke-Davis (Pfizer) and Eli Lilly. During hearings on marijuana law in the 1930’s, claims were made about marijuana’s ability to cause men of color to become violent and solicit sex from white women. This imagery became the backdrop for the Marijuana Tax Act of 1937 which effectively banned its use and sales.

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Indications

Medicinal cannabis is now legal and available for medicinal use in Australia. Treatment with medicinal cannabis is not about curing the condition being treated. It is about alleviating symptoms, generally with mild side effects, and improving quality of life. There is the potential for one medication to assist with multiple symptoms. The main uses at present are listed below. According to the National Academies of Sciences, there is substantial or moderate evidence for the first 6 in the list, and limited evidence (ongoing trials) for the remainder.

  • Chronic pain in adults – in particular neuropathic
  • Intractable childhood epilepsy (e.g. Dravet Syndrome)
  • Spasticity in multiple sclerosis
  • Chemotherapy induced nausea and vomiting
  • Sleep problems
  • Palliative Care
  • Anxiety including PTSD
  • Fibromyalgia
  • Symptoms of IBS
  • Cancer treatment, incl glioma and cancer-associated anorexia
  • Achieving abstinence in the use of addictive substances
  • Mental health outcomes in individuals with schizophrenia

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Dependency & Safety

Medicinal cannabis is NOT street cannabis where the composition is unknown, and which may even be contaminated with strongly addictive drugs such as heroin or ICE. This may be why it used to be said that teenagers would "start on weed and end up on heroin."

Cannabis is actually less addictive then caffeine, and much less addictive than opioids.

No-one has ever died from an overdose of medicinal cannabis due to the lack of CB1 receptors in the brainstem cardiorespiratory centres.

Medicinal cannabis is relatively expensive. It is not on the PBS (subsidised by government). You need to budget for $200 per month, or more, depending on symptoms and dose needed.

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Entourage effect

Medicinal cannabis is a combination of two main cannabinoids, the psychoactive THC, and the more immune stimulating CBD, along with hundreds of other compounds (terpenes, which give cannabis its odour, and flavonoids). None of the individual cannabinoids have medicinal broad-spectrum properties. Even a trace of THC makes the CBD more effective. This is why synthetic (lab-derived) cannabinoids such as Nabilone have limited effects, or even cause problems. The benefit arises from the combination of all these compounds, called the entourage effect.

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Endocannabinoid system

The human body as and in-built (endogenous) cannabinoid system. This means that, like endorphins (natural opioids), the body can produce cannabinoids on its own. This endocannabinoid system comprising of CB1 & CB2 receptors is a signalling system central to homeostasis. Reference: Green Leaf Options Endocannabinoids bind to the receptors to down-regulate neural pain signals and inflammatory responses.

CB1 receptors are mostly found in the brain and CNS and appear to affect cognitive function. CB2 receptors are mostly found in the immune system. THC mainly attaches to CB1 receptors, producing the psychoactive euphoric "high" of cannabis. CBD does not bind strongly to either receptor but interacts with other pathways such as activating serotonin receptors and encourages higher levels of endocannabinoids such as anandamide, our "happy molecule".

THC is more euphoria-producing so very useful for any painful condition, while CBD is more focus-producing so is more useful in ADD, bipolar, PTSD etc.

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Routes of administration

Cannabinoids need to be heated to become active. Traditionally, people smoked cannabis using a pipe or bong. This burns the cannabis. Cannabis smoke delivers 50-70% more carcinogenic hydrocarbons than tobacco smoke and a higher risk of cardiac arrhythmias.

Although there are a variety of oral options, OILS are the most widely used form of medicinal cannabis. Oils can be made with a variety of THC to CBD ratios. Sprays can be more convenient to administer (personal preference and cost). Juicing & teas do not allow adequate decarboxylation of raw plant to activate the cannabis.

Topicals may help for localised symptoms. Suppositories may be useful for patients with cancer, gastro-intestinal symptoms and in young children or the elderly.

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Oil versus vaping (inhaling)

This chart illustrates the different duration of effects between oral and inhaled cannabis. The oral dosing takes longer to start working but lasts much longer, whereas vaping gives an instant effect but wears off quickly. It is thus possible to use a combination of products – oil for the baseline effect and vaped for breakthrough symptoms, especially with respect to pain and corresponds to long and short-acting opiates.

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Suitability

Medicinal cannabis may not be suitable for everyone:

  • Medicinal cannabis products containing THC are often not appropriate for patients who:
    • Have a previous psychotic or concurrent mood or anxiety disorder
    • Are pregnant or planning on becoming pregnant or breastfeeding
    • Have unstable cardiovascular disease as it may worsen arrythmia
    • Cannabis should be avoided in patients with severe cardiovascular, immunological, liver or kidney disease, especially in acute illness

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Side-effects

  • Medicinal cannabis can have side-effects, but these are generally mild. Notably, there were actually no significant differences between the side-effects reported by people receiving medical cannabis and those who received either placebo or nothing at all -
    • Tiredness
    • Dizziness
    • Psychological effects, especially in adolescents
    • Dry mouth
    • Changes in memory
    • Other physical effects (hypotension - low BP, tachycardia - rapid heart rate)
    • Tolerance can develop quickly
    • Dependence has been reported, estimated at 1:10 illicit users
    • A very small number of patients develop Cannabinoid Hyperemesis Syndrome (CHS), basically an allergy to cannabis.
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    Warning re driving

    Beware of driving while using medicinal cannabis.
    While it is legal to take it for medical purposes, current Victorian law still prohibits driving while there is any THC in your body. Certainly do not drive or operate machinery if you feel impaired.

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      Dosing schedule

      Starting medicinal cannabis oil - start low, go slow, stay low

      Take the oil in your cheek or under the tongue, although you can just swallow it. Start with 0.25ml at night for 3 nights, then increase to twice daily dosing for another 3 days.
      Increase the evening dose to 0.4ml for 3 nights, then to 0.4ml twice daily.
      After these 12 days, you should feel some effect. You now need to decide when in the day you need more (if you do), so you can increase by 0.2ml sometime in the day (morning, middle of the day or night).

      People typically end up needing somewhere between 1.2ml per day up to 2ml per day in divided doses. Occasionally people need more but this can get expensive. What works for you is correct. Take it slowly.

      Review in a week. After a month, the ratio may need to be tweaked. Build up the cannabis dose first then gradually reduce opioids etc. Don't come off routine medications suddenly, but many patients find they can reduce their use of pregabalin, benzodiazepines and even opioids. Discuss any intended changes with the doctor.

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      Vaping flower

      Vaporisation heats the cannabis leaf (don't put oil in the device!) at 160-230°C which is lower than smoking, thus higher bioavailability and fewer harmful effects (takes out the cancer-causing by-products of burning cannabis). Effects are generally felt within minutes and last up to 2-3 hours. The higher the temperature, the stronger the effect. It generally uses plant leaves which are rich in THC, the psychoactive component. Different strains are available.

      Indica strains are more physically sedating, so better for relaxing or a nightcap before bed.
      Sativa strains tend to deliver more energising effects so are better with physical activity, social events and creative projects. Hybrid strains are a combination from the result of crossbreeding cannabis strains. In addition, the terpenes contribute to the entourage effect. You may need to experiment with several products to see which works best for your needs. We can offer you a choice and recommendations.

      A selection of vapourisers are available at varying prices. The cheaper portable ones may be more convenient but tend to use up more of the product. Desktop models such as the Volcano may work out cheaper in the long run for regular use. Most vapourisers use 0.25 gram per use.

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      Preparing for your first medicinal cannabis appointment

      When you are coming for your appointment, please bring a summary of your medical condition, including previous and current treatments. What symptoms do you want to relieve? Ideally write these points down and bring the list with you. You should also download and complete the I'm new to the practice patient form. Finally, it may not be possible to fully fix the problem, and, at present, the cost of the medicinal cannabis can be significant - over about $200 per month.

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