Medicinal Cannabis & Pain Management

A new era in contemporary healthcare has begun with the legalisation of cannabis products for medical purposes. Another name for marijuana, this has been used for recreational and medicinal purposes for centuries. In all Australian states and territories, any use at all was illegal until recent changes to the law in February 2016.

What is in medicinal cannabis?

Cannabis is a plant that contains hundreds of chemicals, which are of interest due to their possible medicinal effects on the human body. These chemicals are thought to be associated with a number of therapeutic benefits, including pain relief and anti-inflammatory effects. The nature and degree of benefit remains the focus of ongoing research.

The main chemicals available in the prescribed cannabis preparations are tetrahydrocannabinol (THC) and cannabidiol (CBD). Essentially, these chemicals resemble those that occur naturally in the human nervous system in the endocannabinoid pathways, so delivering more of them to the body may promote or enhance their effects.

THC is a psychoactive substance, and like any medicine, has positive and negative effects. THC is the component that is responsible for the “high” that can accompany cannabis use, yet it also appears to be associated with pain relief. Importantly, THC is not essential to achieving effective pain relief, which is particularly relevant given most studies demonstrate common neurocognitive side effects, that include altered thinking, headache, mood elevation, poor concentration, and sedation or sleepiness. More worrying psychiatric effects are uncommon yet can occur and probably occur at higher dosages. More commonly, effects on mood, stress, and sleeplessness are considered helpful for many people with persistent pain.

CBD is not associated with psychiatric effects and is thought to offer an array of therapeutic benefits. These might include improvements in pain, physical function, and sleep quality. As for THC, CBD can cause minor temporary adverse effects, such as dizziness and slower thinking.

Prescribed cannabis preparations, obtained with a prescription from your pharmacy generally contain THC or CBD, or a combination of these. Your prescribing doctor may discuss these options with you and prescribe according to your individual symptoms and needs.

Can I obtain and use cannabis and marijuana without a prescription?

The use of any type of cannabis without a prescription is illegal in all Australian states and territories.

Prescribed pharmaceutical-grade cannabis preparations have important advantages over cannabis obtained by other means. Firstly, the precise quantities of active ingredients are known to your prescriber and have been chosen according to your symptoms and needs. Also, the concentrations of chemical remain consistent with each prescription dispensed over time, ensuring that any benefits remain predictable. Any change in your clinical condition can be assessed with the knowledge that your dose of medication has not altered. Finally, you and your doctor may decide to minimise THC or CBD intake so as to customise the effects & side-effects of your prescription.

Will I collect my cannabis on the same day?

Once you have found yourself with a doctor who prescribes these products, there may be some delay while government authorisation is given for you to use cannabis medicinally. When you have obtained your prescription, it may take a number of days for the pharmacy to receive that from the supplier before it can be dispensed to you.

How do I use medicinal cannabis? Is it easy to administer?

These products can be taken in several ways, depending on the type of preparation obtained. Some formulations are smoked or inhaled via a vaporiser, and these provide the most rapid rise of chemicals in your bloodstream, and subsequently may have a faster (and sometimes briefer) clinical effect when compared with other forms of administration. Also, 40% or more of the useful chemical content is destroyed by heat during smoking, so the dose administered is not always clear.

Vaporising is less destructive to the chemicals due to lower temperatures, and there is less production of toxins. This is thought to produce less unwanted negative effects from smoking, and also means “passive” exposure (to others nearby) is less concerning. Both approaches to inhaling medicinal cannabis, smoked or vaporised, are said to have a duration of 2-4 hours per dose. Both approaches are associated with other health concerns such as respiratory (breathing) damage.

Some forms are absorbed from under the tongue, by spraying the inside of the mouth or by swallowing. These approaches provide a slower rise of chemicals in the blood and therefore a slower and less intense clinical effect, but a longer duration of 8-24 hours. Effectiveness of skin preparations is unclear.

How much does it cost?

Any visit to a GP is subsidised by the Medicare fee. If the GP bulk bills the cost of the visit is then 100% paid for under Medicare. GPs who do not bulk bill will charge the patients an additional fee (out of pocket expense). Visits to a MC prescriber are generally not bulk billed. There will be a private fee consultation. Most MC prescribers use Telehealth for consultations. Telehealth is not subsidised by Medicare and the full fee is charged to the patient.

The products must be obtained from a pharmacy and can be expensive. Sometimes a prescriber will advise the use of different formulations for different parts of the day; however, more prescriptions will increase your expenses . Depending on the level of any private cover you have purchased, you may be eligible for some prescription cost rebate through private health insurance. You may also need to consider the costs of any devices required, such as vaporisers.

Can I drive while taking this medicine?

Driving laws vary from region to region and should be discussed with your prescriber before commencing any of these medicines.

In most states and territories, it remains illegal to drive with evidence of THC in your body. Unfortunately, many preparations of CBD alone may still contain small amounts of THC which, if detected at a roadside testing, may see you in breach of the law. It may also disqualify you from claiming driving related injuries or property damage on insurance in the event of a motor vehicle accident.

Can I take my medicine overseas?

Many countries continue to prohibit all forms of cannabis. They do not allow a person to bring these products with them, even when prescribed. Failing to comply with the laws may result in very serious consequences.

Refer to the Australian’s Government’s Office of Drug Control for more information.

Why do so many doctors oppose medical use cannabis in chronic non-cancer pain?

A standard ethic of medical care is to ensure that whatever else you do, never bring harm to your patient. Of course, there are many examples where treatment approaches bring unpleasant results, but these are accepted in the context of more important benefits which are also achieved; an example is a leg amputation to arrest the spread of a cancer. Doctors are already aware of some disadvantages associated with cannabis ingestion. When trying to balance this against any proven advantages, there is thought to be insufficient research evidence to prove benefit. That is substantially because the research studies currently available are not sufficient to provide adequate conclusions from which doctors can reliably form opinions and advise patients. Accordingly, the current advice from the specialist bodies is that the use of cannabis products for chronic non-cancer pain is not supported. (Links are provided below.)

Will prescribed cannabis improve my activities of daily living and quality of life?

As with all treatments, regardless of their level of impact, the most important aspect of treatment is the gradual rebuilding of behaviours and involvements which have slipped away over the preceding months and years. This is usually challenging, yet may be at least somewhat achievable if undertaken carefully, sensibly and especially gradually, and often with professional input.

Treatments which reduce pain and distress serve only to do just that, but will not ever rectify the deterioration that is caused through long periods of lost activities and involvements. Only reactivation can address these.

Ideally this important process will be assisted by involvement with a health professional or team in functional restoration. There are also some self-help resources discussed elsewhere on this website.

Resources and references

Australian Government – Therapeutic Goods Administration

Royal Australian College General Practitioners

ANZCA Faculty of Pain Medicine

The Royal Australian & New Zealand College of Psychiatrists

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