The term cannabis-based products covers several types of products that may be prescribed to treat various medical conditions.
What is the difference between medicinal cannabis and recreational cannabis?
Medicinal cannabis is the use of cannabis-based products for medicinal purposes, to relieve the symptoms of a medical condition. Recreational cannabis is the use of cannabis without any medical reason for the purpose of getting ‘high’.
Cannabis-based medical products
- The medicinal cannabis scheme was set up in April of 2020 so that all cannabis-based products meet strict good manufacturing practice (GMP) standards to ensure their safety. Read more about the medicinal cannabis scheme.
- Evidence of the safety and efficacy of most individual products from clinical trials is lacking. This is why cannabis-based products are considered 'unapproved medicines'. Read more about unapproved medicines.
Read more prescribing cannabis-based products (Medsafe, NZ)
What are cannabis-based products?
Cannabis-based products generally contain 2 main ingredients – cannabidiol (CBD) and tetrahydrocannabinol (THC). They may also contain other chemicals related to CBD and THC (called cannabinoids) and natural aromatic and potentially beneficial compounds called terpenes.
Cannabis-based products either come from the cannabis plant (marijuana) or they can be synthetic. Synthetic products are human-made chemicals that have the same chemical structures as CBD and THC.
All cannabis-based medicines currently available are derived from the cannabis plant and are not synthetic.
|Cannabidiol (CBD)||Tetrahydrocannabinol (THC)|
Medicinal cannabis products in New Zealand
In New Zealand most medicinal cannabis-based products (except Savitex – see below) are classified as ‘unapproved medicines’. This means that although they are legal, they are not registered by Medsafe to treat a specific condition or symptom. Read more about unapproved medicines.
There are currently no New Zealand-made medicinal cannabis products. They are all imported from overseas. Currently the following importing companies have CBD products available:
- Nubu Pharmaceuticals
- Mercury Pharma
Although THC products are available on prescription, there are no products available on the market to be prescribed without approval. This means that THC prescriptions require a Ministry of Health approval by your specialist to allow you to gain access. The only exception to this is Sativex.
Savitex is approved in New Zealand for use in people with multiple sclerosis to improve symptoms of moderate-to-severe spasticity (muscle tightness, stiffness or spasms). Any other use of Sativex is an unapproved use of this medicine in New Zealand. Any New Zealand-registered medical practitioners can prescribe Sativex.
Sativex contains both THC and CBD. It is available as an oromucosal spray (mouth spray) and is not funded, which means that you have to pay for it. Read more about Sativex.
Formulations of medicinal cannabis
Medicinal cannabis is NOT usually smoked. It is usually available as:
- oral drops, lozenges, capsules
- oromucosal spray (mouth spray)
- inhaled via a medical vapourisor device (non-combustion)
- gel or patches that are applied to your skin.
Do cannabis-based medicinal products work?
The scientific evidence for the effectiveness and safe use of cannabis-based products is not considered strong. In general there is not yet enough information to fully recommend their use. One of the main issues is that there are limited pharmaceutical grade cannabis-based products available for use. Certain cannabis-based products may provide some moderate improvements in symptoms for people with:
- multiple sclerosis-associated spasticity
- seizures associated with refractory epilepsy such as Dravet syndrome or Lennox-Gastaut syndrome
- chronic pain, specifically nerve pain
- nausea and vomiting caused by cancer therapy
- sleep problems.
Trialling a cannabis-based product is only a suitable option for people who have ongoing symptoms after trying available conventional treatments. Evidence is lacking to support the use of cannabis-based products for depressive disorders, post-traumatic stress disorder (PTSD), Parkinson’s disease, anxiety, obsessive-compulsive disorder (OCD), autism, ulcerative colitis, Alzheimer’s disease, glaucoma and Crohn’s disease.
Doctors usually recommend starting a cannabis-based product at a low dose and gradually increasing it to avoid possible side effects.
The recommended dose is difficult to ascertain due to individual differences: some people are very sensitive to it whereas others need to use more to feel an effect. Other reasons that make dosing difficult to determine include the following:
- Products have different ratios of CBD and THC which can affect the body in different ways when used in a combination. This means that finding the right dose needs trying first and then adjusting.
- Individual differences exist and some find that their dosage needs to change when the product brand is changed.
- Cannabis-based products intended for inhalation are harder to dose. Flower-based products require the use of a medical vaporizer, which helps control the dose received by adjusting the temperature and amount of product used. However, this is not an exact science and it makes dosing harder to determine.
Cannabis-based products can cause many side effects and these differ between products. Common mild side effects include:
- nausea (feeling sick)
- indigestion, stomach upset
- stomach pain or cramps
- diarrhoea (runny poos)
- dry mouth.
No studies have yet assessed the long-term adverse effects of cannabis-based products. The THC component of cannabis-based products is not appropriate for people who:
- have a personal or strong family history of psychosis
- have active mood disorder
- are pregnant and breastfeeding
- have heart rhythm problems
- have had recent heart attacks or strokes
- have severe liver problems.
Travelling with cannabis
New Zealand law allows people arriving in New Zealand to bring in up to 1 month’s supply of a controlled drug, as long as they have been lawfully supplied this in the country of origin for the purpose of treating their medical condition. Some countries have limitations in place restricting people from leaving with cannabis-based products. For further information on bringing medicines into New Zealand, see bringing medicines into New Zealand.
Sativex® Oromucosal Spray Medsafe, NZ
Savitex (Nabiximols) Multiple Sclerosis NZ
CBD products Ministry of Health, NZ
Medicinal cannabis scheme Ministry of Health, NZ, 2020
Medicinal cannabis agency Ministry of Health, NZ, 2020
- Medicinal cannabinoids: current regulations for prescribing BPAC, NZ, 2018
- Committee on the Health Effects of Marijuana. The health effects of cannabis and cannabinoids: The current state of evidence and recommendations for research The National Academic Press, 2017
- Allan MG, Finley CR, Hauptman R, Beahm NP. Missing ‘high’ quality evidence for medical cannabinoids for pain? Alberta College of Family Physicians, Tools for Practice. 2017
- Whiting PF, Wolff RF, Deshpande S et al. Cannabinoids for medical use; a systematic review and meta-analysis Journal of the American Medical Association 2015;313(24):2456-73
- Newton-Howes G, McBride S. Medicinal cannabis: moving the debate forward New Zealand Medical Journal. 2016; 129(1445).
- Walitt B, Klose P, Fitzcharles MA et al. Cannabinoids for fibromyalgia. Cochrane Database of Systematic Reviews, 2016
- Mouhamed Y, Vishnyakov A, Qorri B, et al Therapeutic potential of medicinal marijuana: an educational primer for healthcare professionals Drug Healthc Patient Saf. 2018 Jun 11;10:45-66. doi:10.2147/DHPS.S158592
|Dr Waseem Alzaher is a GP with a special interest in medicinal cannabis. His interest and belief in plant-based medicine led him to start the Cannabis Clinic.|