Medicinal cannabis

What is medicinal cannabis?

Medicinal cannabis means cannabis products manufactured to a therapeutic standard and supplied on prescription. Most products used in Australia are unapproved therapeutic goods: they are not entered on the Australian Register of Therapeutic Goods, so the TGA has not evaluated them for safety, quality, and effectiveness in the same way as registered medicines.1

Quality, cannabinoid content, and the clinical question all depend on the specific product. Pathway status does not change the pharmacology.2

What are cannabinoids?

Cannabinoids are a family of compounds from Cannabis sativa and related synthetic or isolated substances. Delta-9-tetrahydrocannabinol (THC) is intoxicating at sufficient dose. Cannabidiol (CBD) is not intoxicating in the same way, but it is still a medicine with its own metabolism, adverse effects, and interaction potential.3

Many prescribed products contain both, in different ratios, plus minor cannabinoids and terpenes. Label strength is not interchangeable across routes.4

What does the clinical evidence actually support?

The 2017 National Academies review — the current successor to earlier Institute of Medicine cannabis reports — is still the standard peer-reviewed map of benefits and harms. There is no Institute of Medicine interaction API; conclusions below are taken from that report, not from a live feed.5

Conclusive evidence: oral cannabinoids are effective antiemetics in adult chemotherapy-induced nausea and vomiting.6

Substantial evidence: cannabis is effective for chronic pain in adults, and oral cannabinoids improve patient-reported (not always clinician-measured) spasticity symptoms in multiple sclerosis.7

Those conclusions are population-level evidence grades. They are not an indication list, a product endorsement, or a reason to skip TGA pathway conditions and product information.8

Where is THC-containing medicinal cannabis generally not appropriate?

TGA overview guidance is that THC-containing medicinal cannabis is generally not appropriate in previous or current psychosis, a concurrent active mood or anxiety disorder, unstable cardiovascular disease, or in pregnancy, planning pregnancy, or breastfeeding. Unapproved cannabis products are not ARTG-listed for those conditions.9

The National Academies found substantial evidence of a statistical association between cannabis use and the development of schizophrenia and other psychoses, with the highest risk among the most frequent users, and substantial evidence that maternal cannabis smoking is linked with lower birth weight.10

How is medicinal cannabis accessed in Australia?

Special Access Scheme Category B is a named-patient application before supply. Authorised Prescriber is for a class of patients and is available to medical practitioners; six-monthly reporting applies. From 28 April 2022, compounding an unapproved medicinal cannabis product also requires SAS or AP.11

AHPRA’s position is that most medicinal cannabis products remain unapproved, THC-containing products are typically Schedule 8, and they should be prescribed with the same diligence as other Schedule 8 medicines, including real-time prescription monitoring and My Health Record where they apply.12

What is the difference between S4 CBD and S8 products?

NSW Health notes that an approval from NSW is not needed to prescribe a Schedule 4 cannabis medicine, while Schedule 8 unregistered products attract extra state rules in defined cases. Pharmacists still apply Schedule 8 handling, recording, and monitored-medicine checks to THC-containing products.13

Do not guess the schedule from the brand name. Read the product’s cannabinoid composition and the current Poisons Standard entry.14

How do people take it, and why does route matter?

Common forms include oils and extracts, capsules, oromucosal sprays, pastilles, and dried flower for inhalation. A flower product and an oil with a similar labelled THC or CBD content are not equivalent for onset, duration, or first-pass exposure.15

Why do drug interactions matter?

TGA guidance asks prescribers to consider drug–drug interactions as part of ordinary medicinal-cannabis review. Enzyme-level checking sits beside product information and clinical judgement; it is not a dosing instruction.16

What should a pharmacist check before supply?

In NSW, a pharmacist may dispense an unregistered cannabis medicine if the prescriber holds TGA Authorised Prescriber or SAS approval. Unregistered products cannot be held in stock unless they have been approved for supply to a particular patient. Substitution of products is not allowed. Prescriptions must identify name, strength (not a range), dose, and quantity.17

In Tasmania, unregistered products generally cannot be released by the supplier until the pharmacy provides a copy of the SAS or AP approval. Other jurisdictions have their own monitored-medicine systems (QScript, SafeScript, and equivalents).18

State and territory rules

Commonwealth TGA approval does not replace poisons law. Queensland does not add a second state approval for S4 CBD or S8 THC once TGA approval is held; Tasmania still requires a Section 59E authorisation for each Schedule 8 patient. Pharmacist stocking, substitution, and monitored-medicine systems differ by jurisdiction.19