What are the most common medical cannabis routes of administration?
For doctors looking to prescribe cannabis medicine to eligible patients, selecting the most suitable administration method is important.
With more than medicinal cannabis products now available on the Australian market, medical practitioners can apply to access cannabis products in various forms, depending on the most suitable dosing method for each patient.
To put it simply, there are two main methods of consumption for cannabis: inhalation and ingestion. Both of which have different absorption effects on the body.
To help you find the best product for each patient, let’s take a look at the common administration routes available for cannabis medicine:
Smoking medical cannabis (Inhalation)
When it comes to cannabis use, inhalation by smoking is the most associated route of administration, particularly with recreational use. However, this is not the recommended method of consumption.
Did you know, at least 40% of the THC dose in cannabis is lost in side stream/combustion when smoked? Not only does this waste product but the variability makes it hard to determine the exact THC or CBD dose the person is receiving.
As smoking anything can cause exposure to byproducts of combustion, including carbon monoxide, smoking of cannabis products should not be supported.
Vapourising medical cannabis (Inhalation)
For patients who require a fast onset with rapid relief, vapourising can be a suitable method of administering medical cannabis. Heated at a lower temperature than smoking, vapourising produces fewer toxins with no side stream smoke.
By heating the cannabis without burning it, the cannabinoids and terpenes are released in the form of vapour, which is then inhaled by the user.
As vapourising produces consistent temperatures, patients are better able to predict onset while finding their optimal dose under medical supervision. The amount of THC and other cannabinoids delivered to the patient through a vapouriser can be variable depending on the temperature of the vape and the duration of the vapourisation.
Currently, there are no vapourisers registered in Australia as therapeutic goods. However, medical practitioners can still prescribe vapourisers with a TGA approval using BHC’s CanView.
Oral administration (Ingestion)
Oral administration is the most commonly prescribed route of administration for medical cannabis in Australia. With low bioavailability (around 10-20%), oral cannabinoids are absorbed at a much slower rate than inhaled cannabinoids.
As the peak effects can still be noticeable two to four hours after consumption, allowing at least three hours before administering another dose is critical to avoid taking too much.
In fact, unlike the inhalation routes, patients can still experience effects of ingested cannabis anywhere from eight to 24 hours after taking their first dose.
With a slower onset and longer duration than inhalation methods, cannabis oils or liquid capsules are becoming increasingly favoured among prescribing health professionals. In fact, according to the , oral liquid and oil are the top prescribed dosage forms in Australia.
Data retrieved from TGA Medicinal Cannabis Access Data Dashboard (Special Access Scheme Category B data).
My patient doesn’t like the taste of cannabis oil – Is there anything they can do to make the taste better?
As cannabinoid extracts can be quite bitter when consumed orally, some patients may not be too fond of the taste when it comes to cannabis oils.
However, there are a few simple ways you can advise them to mask the taste without losing any quality.
- Eat something with fat in it – Suggest to your patient to try coating their mouth first by eating something containing fat, like avocado or yoghurt, before and after taking the oil. This will not only help alleviate the strong taste but will assist with absorption.
- Try capsules instead of oil – Capsules are a convenient way for patients to avoid any unpleasant tastes of cannabis oils. However, as not all CBD or THC oils come in capsule form, this may not be an option for patients requiring certain cannabis products.
Oro-mucosal sprays (Ingestion)
Derived from the name ‘Oral Mucosa’, which is the mucous membrane lining inside the mouth, oro-mucosal sprays are administered as a spray directly under the tongue. The effects typically begin at about 90 minutes after administering the first dose. Similarly, to the oral administration route, the effects tend to last anywhere from eight to 24 hours.
Although self-titration is much easier with this administration route, it’s important to let your patients know that due to the high alcohol content in oro-mucosal sprays, overuse may cause lesions in the mouth.
Topical medical cannabis
Medical cannabis products can also be prescribed to eligible patients in a topical form. Unlike popular belief, topical products do not penetrate beyond the skin.
While topicals can potentially be ideal for surface-level symptoms, such as skin conditions or skin inflammation, they are often not recommended for patients seeking deeper symptom relief. This is because most topical CBD products do not make it passed the epidermis (first layer of skin) and into the bloodstream where the full effects are achieved.
When to stop using medical cannabis
Prescribing doctors should monitor the effects of medicinal cannabis on each patient and cease the medication when the following occurs:
- the desired effect is not apparent after 4–12 weeks; and
- psychoactive or other side-effects are prohibitive (particularly for THC preparations).
When dosing medical cannabis to patients, no matter the administration route, always advise your patients to “Start low and go slow” to find their minimum effective dose.
The contents in this article do not constitute legal advice, are not intended to be a substitute for legal advice and should not be relied upon as such. You should seek legal advice or other professional advice in relation to any matters you or your organisation may have. Information in this article was correct at time of publishing but please check your own state regulations for updates.
CanView does not endorse the use of medicinal cannabis without lawful prescription. Just like any medicine, medicinal cannabis may have both positive and negative side effects on the user and should only be prescribed to patients by a health professional with the authority and expertise to do so. The information provided by CanView is for informational and educational purposes and is of a general nature. Patients considering medical cannabis are advised to speak to their general practitioner first to see if it’s a suitable therapy.